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Revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Peru: classification, phylogeny, and a new species, M. romaschenkoi
expand article infoPaul M. Peterson, Isidoro Sánchez Vega§, Konstantin Romaschenko, Diego Giraldo-Cañas|, Nancy F. Refulio Rodriguez
‡ National Museum of Natural History, Smithsonian Institution, Washington, United States of America
§ Universidad Nacional de Cajamarca, Cajamarca, Peru
| Universidad Nacional de Colombia, Bogotá, Colombia
¶ ResearchGate, Berlin, Germany
Open Access

Abstract

A taxonomic treatment, phylogeny based on analysis of six DNA sequence markers (ITS, ndhA intron, rpl32-trnL, rps3, rps16 intron and rps16-trnK) and classification of Muhlenbergia for Peru is given. Seventeen species and one presumed hybrid are recognised. Muhlenbergia romaschenkoi sp. nov. is newly described from the Río Huallaga Valley, northeast of Huánuco. The type of Podosemum angustatum [≡ Muhlenbergia angustata] clearly aligns with what we had been referring to as the hybrid between this species and M. rigida. Therefore, we adopt the next available heterotypic name, Muhlenbergia coerulea, for what we had been calling M. angustata and change the hybrid designation to M. coerulea × M. rigida. Lectotypes are designated for Epicampes coerulea Griseb., Muhlenbergia affinis Trin., Muhlenbergia berlandieri Trin., Muhlenbergia beyrichiana Kunth, Muhlenbergia elegans var. atroviolacea Kuntze, Muhlenbergia elegans var. subviridis Kuntze and Muhlenbergia phragmitoides Griseb.

Resumen

Brindamos un tratamiento taxonómico, una filogenia basado en el análisis de seis marcadores de secuencia de ADN (ITS, intrón ndhA, rpl32-trnL, rps3, intrón rps16, rps16-trnK) y la clasificación de Muhlenbergia para Perú. Se reconocen diecisiete especies y un supuesto híbrido. Muhlenbergia romaschenkoi sp. nov. es descrita como especie nueva procedente del valle de Huallaga, al noreste de Huánuco. El tipo de Podosemum angustatum [≡ Muhlenbergia angustata] se alinea claramente con lo que nosotros habíamos referido como el híbrido entre esta especie y M. rigida. Por lo tanto, adoptamos el siguiente nombre heterotípico disponible, Muhlenbergia coerulea para lo que habíamos estado llamando M. angustata, y cambiamos la designación híbrida a M. coerulea × M. rigida. Los lectotipos son designados para Epicampes coerulea Griseb., Muhlenbergia affinis Trin., Muhlenbergia berlandieri Trin., Muhlenbergia beyrichiana Kunth, Muhlenbergia elegans var. atroviolacea Kuntze, Muhlenbergia elegans var. subviridis Kuntze y Muhlenbergia phragmitoides Griseb.

Keywords

classification, ITS, lectotypification, Muhlenbergia, Peru, phylogeny, plastid DNA sequences, Poaceae, systematics, taxonomy

Introduction

Peru is located in the central and western part of South America between 0° and 18° south latitude. The central Andes or backbone divides Peru into three great regions: coast, mountain, and forest (Weberbauer 1936). The coastal region next to the Pacific Ocean is an extremely xeric, narrow, sandy plain that rises abruptly to the east. This region is occasionally transected by river valleys and the climate is very mild and warm. The mountain region or ‘‘cordillera de Andes’’ consists of high peaks and extensive high plains (altiplano) that are sometimes dissected by deep, narrow valleys. The climate in this region can be very cold and it is not uncommon to have snow above 3800 m. The tropical forest region, east of the cordillera, extends into the Amazonian river basin where there are high levels of biodiversity associated with many different habitats. The climate here is very warm and humid with high levels of precipitation and there are large rivers including the Río Marañon and the Río Ucayali that feed into the Río Amazonas.

The Poaceae is a diverse family occupying a myriad of terrestrial habitats in Peru, with the exception of the permanent snow fields. The taxonomic knowledge of this family in Peru is incomplete and it is still possible to encounter novel species.

Hitchcock (1927), in his treatment of the grasses of Ecuador, Peru and Bolivia, recognised 12 species of Muhlenbergia Schreb., 10 of these being reported in Peru. Standley (1936), in his Flora of Peru, recorded 10 species. More recently, Tovar (1993) produced an integral study of the Peruvian grasses, including 14 species of Muhlenbergia. Brako and Zarucchi (1993) list 13 species as being present in Peru. All of these treatments are out of date and, subsequently, there have been new reports of grasses from Peru. As Muhlenbergia is a relatively large genus in North and Central America and is easily dispersed, a modern investigation was undertaken to more clearly understand its systematics and biogeography. In Peru, we report 17 species of Muhlenbergia (one of these is new) and one proposed hybrid.

The subtribe Muhlenbergiinae Pilg. (tribe Cynodonteae Dumort.) is a diverse assemblage of 182 species represented by a single, monophyletic genus, Muhlenbergia (Peterson et al. 2010a, b; 2016; Soreng et al. 2017; Peterson et al. 2018). Species within Muhlenbergia are morphologically highly variable and are characterised in having membranous ligules (rarely a line of hairs); paniculate inflorescences that are rebranched or composed only of primary branches; spikelets that are usually solitary but sometimes in pairs or triads, with cleistogenes (self-pollinated flowers that do not open at maturity) occasionally present in the leaf sheaths; one floret (rarely more) per spikelet that is perfect, staminate or sterile; glumes that are awned or unawned; lemmas 3-nerved, apex awned or unawned; and a base chromosome number of x = 8−10 (Peterson et al. 1995, 1997, 2007a, b; Peterson 2000, 2003). Two subtypes of C4 photosynthesis based on nicotinamide adenine dinucleotide cofactor malic enzyme (NAD-ME) and phosphoenolpyruvate carboxykinase (PCK) have been found in Muhlenbergia; subtypes in most species have been verified by anatomy and in a few species by biochemical assay (Gutierrez et al. 1974; Brown 1977; Hattersley and Watson 1992).

Based on seven molecular markers (nuclear ITS and plastid ndhA intron, ndhF, rps16-trnK, rps16 intron, rps3 and rpl32-trnL), Peterson et al. (2010b) provided a phylogeny and classification for 124 species (68%) of the Muhlenbergiinae. They recognised five subgenera within Muhlenbergia: M. subg. Bealia (Scribn.) P.M. Peterson, M. subg. Clomena (P. Beauv.) Hack., M. subg. Muhlenbergia, M. subg. Pseudosporobolus (Parodi) P.M. Peterson and M. subg. Trichochloa (P. Beauv.) A. Gray. Here we present an updated phylogeny of 146 species (80%) of Muhlenbergia with 13 new species based on six molecular markers (nuclear ITS and plastid ndhA intron, rpl32-trnL, rps3, rps16 intron and rps16-trnK), classification and a taxonomic revision of the genus for Peru.

Material and methods

Phylogenetic analyses

Detailed methods for DNA extraction, amplification, sequencing and phylogenetic analysis are given in Peterson et al. (2010a, b, 2014a, 2015a, b, 2016). In brief, the phylogeny was estimated among members of Muhlenbergia based on the analysis of six molecular markers (nuclear ITS 1&2, and plastid ndhA intron, rpl32-trnL, rps3, rps16 intron, rps16-trnK). We sampled most species within subtribe Muhlenbergiinae and included outgroups: Distichlis scoparia (Nees ex Kunth) Arechav. (Monanthochloinae Pilg. ex Potztal), Willkommia sarmentosa Hack. (Traginae P.M. Peterson & Columbus) and Sporobolus indicus L. (Zoysieae Benth., Sporobolinae Benth.) [Peterson et al. 2010a, 2015a, 2014b, 2016; Soreng et al. 2017]. Voucher information and GenBank numbers for all samples (including the new ones) are given in Table 1.

The resulting plastid and ITS topologies were inspected for conflicting nodes with posterior probabilities (PP) ≥ 0.95. If no supported conflict was found, plastid and ITS sequences were combined (Figure 1). When conflicting topologies were present, the datasets for inconsistently placed taxa were duplicated in the matrix. One set of the taxon was represented by only the corresponding plastid sequences, the other taxon set by only ITS sequences. The remaining positions for the duplicated datasets were then coded as missing data. We use this “taxon duplication” approach (Pirie et al. 2008; Pelser et al. 2010; Peterson et al. 2015b, 2016) to resolve our phylogenetic tree, minimising the diffusing effects of taxa with strongly supported incongruence between the plastid and ITS data and to represent their alternative placements in relation to the remaining phylogenetic groups, among which relationships are congruent.

Figure 1. 

A, B Maximum-likelihood tree inferred from combined plastid (ndhA intron, rps16-trnK, rps16 intron, rps3, and rpl32-trnL) and ITS sequences. Thick branches indicate posterior probabilities of 0.95−1; species in red occur in South America; scale bar = 2%.

Taxon voucher (collector, number, and where the specimen is housed), country of origin, and GenBank accession for DNA sequences of rps3, rps16-trnK, rps16 intron, ndhA intron, rpl32-trnL, and ITS regions (bold indicates new accession); a dash (−) indicates missing data; an asterisk (*) indicates sequences not generated in our lab.

N Taxon Voucher Country rps3 rps16-trnK rps16 intron ndhA intron rpl32-trnL ITS
Outgroup
1 Distichlis scoparia var. erinacea (Nees ex Kunth) Arechav. Peterson 17475, Soreng & Refulio-Rodriguez (US) Argentina, Neuquen GU360034 GU360501 GU360477 GU359480 GU359803 GU359334
2 Sporobolus indicus (L.) R. Br. Peterson 22025 & Saarela (US) Mexico, Chihuahua GU360161 GU360630 GU360355 GU359504 GU359913 GU359209
3 Willkommia sarmentosa Hack. Schweickerdt 2181 (US) South Africa GU360252 GU360645 GU360343 GU359545 GU359924 GU359194
Muhlenbergia
4 Muhlenbergia ramulosa (Kunth) Swallen Peterson 22447 & Saarela (US) Mexico, Durango GU360254 GU360717 GU360406 GU359444 GU359953 GU359115
5 Muhlenbergia ramulosa (Kunth) Swallen Peterson 24521 & Romaschenko (US) Mexico, Coahuila MK090816 MK090876 MK090848 MK090728 MK090773 MK090686
6 Muhlenbergia ramulosa (Kunth) Swallen Peterson 24697, Romaschenko & Zamudio Ruíz (US) Mexico, Queretaro MK090817 MK090877 MK090849 MK090729 MK090774 MK090687
subg. Bealia
7 Muhlenbergia annua (Vasey) Swallen Peterson 22022 & Saarela (US) Mexico, Chihuahua HM143247 HM143629 HM143534 HM143351 HM143144 HM143043
8 Muhlenbergia arenicola Buckley Peterson 19947 & Lara-Contreras (US) Mexico, Coahuila GU360209 GU360674 GU360413 GU359462 GU359960 GU359166
9 Muhlenbergia argentea Vasey Peterson 22095 & Saarela (US) Mexico, Chihuahua HM143248 HM143630 HM143535 HM143352 HM143145 HM143044
10 Muhlenbergia arizonica Scribn. Peterson 22173 & Saarela (US) Mexico, Chihuahua HM143249 HM143631 HM143536 HM143353 HM143146 HM143045
11 Muhlenbergia biloba Hitchc. Peterson 7946, Annable & Herrera (US) Mexico, Chihuahua GU360098 GU360550 GU360309 GU359859 GU359258
12 Muhlenbergia brevis C.O. Goodd. Peterson 22023 & Saarela (US) Mexico, Chihuahua HM143253 HM143635 HM143540 HM143357 HM143150 HM143049
13 Muhlenbergia capillipes (M.E. Jones) P.M. Peterson & Annable Peterson 20013 & Sánchez Alvarado (US) Mexico, Durango MK090802 MK090862 MK090835 MK090714 MK090751 MK090664
14 Muhlenbergia caxamarcensis Lægaard & Sánchez Vega Peterson 21965, Soreng & Montoya Quino (US) Peru, La Libertad HM143256 HM143639 HM143543 HM143360 HM143153 HM143052
15 Muhlenbergia depauperata Scribn. Peterson 21293, Saarela & Flores Villegas (US) Mexico, Zacatecas HM143261 HM143642 HM143547 HM143363 HM143157 HM143056
16 Muhlenbergia eludens C. Reeder Peterson 22188 & Saarela (US) Mexico, Sinaloa HM143268 HM143649 HM143554 HM143370 HM143164 HM143062
17 Muhlenbergia filiformis (Thurb. ex S. Watson) Rydb. Peterson 10433, Annable & Weinpahl (US) USA, California HM143272 HM143653 HM143558 HM143374 HM143168 HM143066
18 Muhlenbergia flavida Vasey Peterson 22237 & Saarela (US) Mexico, Sinaloa HM143273 HM143654 HM143559 HM143375 HM143169 HM143067
19 Muhlenbergia fragilis Swallen Peterson 22194 & Saarela (US) Mexico, Sinaloa HM143275 HM143656 HM143561 HM143377 HM143171 HM143069
20 Muhlenbergia ligularis (Hack.) Hitchc. Peterson 12684, Annable, Lægaard & Soreng (US) Bolivia, La Paz MK090808 MK090868 MK090842 MK090720 MK090760 MK090674
21 Muhlenbergia ligularis (Hack.) Hitchc. Peterson 12792, Annable, Lægaard & Soreng (US) Bolivia, Oruro MK090809 MK090869 MK090843 MK090721 MK090761 MK090675
22 Muhlenbergia ligularis (Hack.) Hitchc. Peterson 21513, Soreng, Torre & Rojas Fox (US) Peru, Ancash MK090810 MK090870 MK090844 MK090722 MK090762 MK090676
23 Muhlenbergia ligularis (Hack.) Hitchc. Peterson 21912, Soreng & Montoya Quino (US) Peru, Cajamarca MK090811 MK090871 MK090845 MK090723 MK090763 MK090677
24 Muhlenbergia majalcensis P.M. Peterson Peterson 4519 & Annable (US) Mexico, Chihuahua HM143295 HM143675 HM143577 HM143394 HM143190 HM143088
25 Muhlenbergia minutissima (Steud.) Swallen Peterson 22012 & Saarela (US) Mexico, Chihuahua HM143300 HM143680 HM143195 HM143093
26 Muhlenbergia minutissima (Steud.) Swallen Peterson 24556 & Romaschenko (US) Mexico, Coahuila MK090813 MK090873 MK090765 MK090679
27 Muhlenbergia shepherdii (Vasey) Swallen Peterson 22452 & Saarela (US) Mexico, Durango GU360102 GU360560 GU360320 GU359419 GU359854 GU359277
28 Muhlenbergia sinuosa Swallen Peterson 7976, Annable & Herrera Arrieta (US) Mexico, Chihuahua HM143323 HM143704 HM143603 HM143419 HM143219 HM143117
29 Muhlenbergia texana Buckley Peterson 22016 & Saarela (US) Mexico, Chihuahua HM143334 HM143714 HM143614 HM143230 HM143128
30 Muhlenbergia torreyi (Kunth) Hitchc. ex Bush Peterson 19429, Soreng, Salariato & Panizza (US) Argentina, Catamarca GU360266 GU360720 GU360267 MK090744 GU359992 GU359118
31 Muhlenbergia tricholepis (Torr.) Columbus Peterson 22099 & Saarela (US) Mexico, Chihuahua GU360103 GU360559 GU360305 GU359418 GU359853 GU359278
32 Muhlenbergia vaginata Swallen Peterson 22417 & Saarela (US) Mexico, Durango HM143718 HM143618 MK090745 HM143234 MK090708
subg. Clomena
33 Muhlenbergia crispiseta Hitchc. Peterson 10768, Annable & Valdes Reyna (US) HM143258
34 Muhlenbergia curvula Swallen Peterson 24830, Romaschenko, Rodriguez Avalos, Herrera-Simoni & Garcia Rodriguez (US) Mexico, Aguascalientes MK090754 MK090667
35 Muhlenbergia flaviseta Scribn. Peterson 22409 & Saarela (US) Mexico, Durango GU360250 GU360685 GU360410 GU359448 GU359957 GU359127
36 Muhlenbergia flaviseta Scribn. Peterson 24923, Romaschenko & González-Elizondo (US) Mexico, Durango MK090839 MK090757 MK090670
37 Muhlenbergia filiculmis Vasey Peterson 11954 & Annable (US) USA, Wyoming HM143271 HM143652 HM143557 HM143373 HM143167 HM143065
38 Muhlenbergia flabellata Mez Senalobo 1985 (MO) Costa Rica, MK090805 MK090865 MK090838 MK090717 MK090756 MK090669
39 Muhlenbergia jonesii (Vasey) Hitchc. Peterson 4861 & Annable (US) USA, California HM143289 HM143669 HM143390 HM143185 HM143083
40 Muhlenbergia montana (Nutt.) Hitchc. Peterson 22046 & Saarela (US) Mexico, Chihuahua HM143301 HM143681 HM143582 HM143398 HM143196 HM143094
41 Muhlenbergia peruviana (P. Beauv.) Steud. Peterson 22440 & Saarela (US) Mexico, Durango GU360221 GU360713 GU360408 GU359446 GU359955 GU359154
42 Muhlenbergia peruviana (P. Beauv.) Steud. Peterson 24696, Romaschenko & Zamudio Ruíz (US) Mexico, Querétaro MK090767 MK090680
43 Muhlenbergia peruviana (P. Beauv.) Steud. Peterson 24721, Romaschenko & Zamudio Ruíz (US) Mexico, Querétaro MK090768 MK090681
44 Muhlenbergia peruviana (P. Beauv.) Steud. Peterson 24943, Romaschenko & Zamudio Ruíz (US) Mexico, Querétaro MK090769 MK090682
45 Muhlenbergia quadridentata (Kunth) Trin. Peterson 16103 & Rosales (US) Mexico, Jalisco HM143313 HM143694 HM143410 HM143209 HM143107
46 Muhlenbergia straminea Hitchc. Peterson 15238 & Cayouette (US) USA, Arizona HM143327 HM143707 HM143607 MK090737 HM143223 HM143121
47 Muhlenbergia virescens (Kunth) Trin. Peterson 22412 & Saarela (US) Mexico, Durango HM143342 HM143722 HM143621 HM143432 HM143238 HM143134
subg. Muhlenbergia
48 Muhlenbergia alamosae Vasey Peterson 22104 & Saarela (US) Mexico, Chihuahua HM143243 HM143626 HM143530 HM143347 HM143140 HM143039
49 Muhlenbergia andina (Nutt.) Hitchc. Peterson 10432, Annable & Weinpahl (US) USA, California HM143244 HM143531 HM143348 HM143141 HM143040
50 Muhlenbergia appressa C.O. Goodd. Peterson 4183 & Annable (US) USA, Arizona GU360211 GU360676 GU360415 GU359443 GU359962 GU359164
51 Muhlenbergia arsenei Hitchc. Peterson 15208 & Cayouette (US) Mexico, Baja California Norte HM143250 HM143632 HM143537 HM143354 HM143147 HM143046
52 Muhlenbergia beyrichiana Kunth Peterson 20366, Soreng & Romaschenko (US) Peru, Huánuco GU360247 GU360712 GU360280 GU359493 GU359995 GU359129
53 Muhlenbergia brandegeei C. Reeder Peterson 4760 & Annable (US) Mexico, Baja California Sur GU360208 GU360711 GU360412 GU359450 GU359959 GU359167
54 Muhlenbergia breviseta Griseb. ex E. Fourn. McVaugh 22930 (US) Mexico HM143636
55 Muhlenbergia bryophilus (Döll) P.M. Peterson Columbus 3565 (RSA) Peru, Cusco GQ397862*
56 Muhlenbergia bushii R.W. Pohl Brant 4542 & O’Donnell (MO) USA, Missouri MK090801 MK090861 MK090834 MK090713 MK090750 MK090663
57 Muhlenbergia californica Vasey Peterson 5013 & Barron (US) USA, California HM143254 HM143637 HM143541 HM143358 HM143151 HM143050
58 Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P.M. Peterson Peterson 22045 & Saarela (US) Mexico, Chihuahua GU360143 GU360578 GU360274 GU359403 GU360011 GU359259
59 Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P.M. Peterson Peterson 24688, Romaschenko & Zamudio Ruíz (US) Mexico, Querétaro MK090752 MK090665
60 Muhlenbergia ciliata (Kunth) Trin. Peterson 22193 & Saarela (US) Mexico, Sinaloa HM143257 HM143640 HM143544 HM143361 HM143154 HM143053
61 Muhlenbergia curtifolia Scribn. Peterson 5631 & Annable (US) USA, Arizona HM143259 HM143641 HM143545 HM143362 HM143155 HM143054
62 Muhlenbergia diversiglumis Trin. Peterson 4611 & Annable (US) Mexico, Chihuahua MK090804 MK090864 MK090837 MK090716 MK090755 MK090668
63 Muhlenbergia dumosa Scribn. ex Vasey Peterson 13438, Knowles, Dietrich & Braxton (US) Mexico, Durango HM143265 HM143646 HM143551 HM143367 HM143161 HM143059
64 Muhlenbergia flexuosa Hitchc. Peterson 20373, Soreng & Romaschenko (US) Peru, Huánuco HM143274 HM143655 HM143560 HM143376 HM143170 HM143068
65 Muhlenbergia frondosa (Poir.) Fernald Yatskievych 04-224, Smith, McKenzie & Nagel (MO) USA, Missouri MK090806 MK090866 MK090840 MK090718 MK090758 MK090671
66 Muhlenbergia glabrifloris Scribn. Brant 2659 (MO) USA, Missouri MK090807 MK090867 MK090841 MK090719 MK090759 MK090672
67 Muhlenbergia glauca (Nees) B.D. Jacks. Peterson 21180, Saarela, Gonzalez Elizondo, Rosen & Reid (US) Mexico, Durango HM143277 HM143659 HM143564 HM143380 HM143174 HM143071
68 Muhlenbergia glomerata (Willd.) Trin. Peterson 20924, Saarela & Howard (US) USA, New York GU360253 GU360716 GU360407 GU359445 GU359954 GU359114
69 Muhlenbergia hakonensis (Hack. ex Matsum.) Makino Kim 2009858 Korea (South) HQ600507*
70 Muhlenbergia himalayensis Hack. ex Hook. f. Soreng 5666, Peterson & Sun Hang (US) China, Xizang HM143281 HM143662 HM143566 HM143383 HM143177 HM143075
71 Muhlenbergia huegelii Trin. Soreng 5344, Peterson & Sun Hang (US) China, Sichuan HM143282 HM143663 HM143567 HM143384 HM143178 HM143076
72 Muhlenbergia japonica Steud. Soreng 5240, Peterson & Sun Hang (US) China, Yunnan HM143287 HM143667 HM143571 HM143388 HM143183 HM143081
73 Muhlenbergia mexicana (L.) Trin. Ladd 13851 (US) USA, Missouri MK090812 MK090872 MK090846 MK090764 MK090678
74 Muhlenbergia mexicana (L.) Trin. Peterson 5562 & Annable (US) USA, New Mexico HM143297 HM143677 HM143580 HM143396 HM143193 HM143090
75 Muhlenbergia mexicana var. filiformis (Torr.) Scribn. Peterson 20861 & Saarela (US) USA, New York. HM143298 HM143678 HM143579 HM143395 HM143192 HM143091
76 Muhlenbergia microsperma (DC.) Kunth Peterson 21855 & Soreng (US) Peru, Cajamarca HM143299 HM143679 HM143581 HM143397 HM143194 HM143092
77 Muhlenbergia pauciflora Buckley Peterson 22048 & Saarela (US) Mexico, Chihuahua HM143686 HM143587 HM143403 HM143201 HM143099
78 Muhlenbergia pectinata C.O. Goodd. Peterson 22108 & Saarela (US) Mexico, Sonora HM143306 HM143687 HM143588 HM143404 HM143202 HM143100
79 Muhlenbergia pereilema P.M. Peterson Peterson 22191 & Saarela (US) Mexico, Sinaloa GU360245 GU360710 GU360282 GU359519 GU359993 GU359131
80 Muhlenbergia plumiseta Columbus Peterson 20106, Hall, Alvarez Marvan & Alvarez Jimenez (US) Mexico, Guerrero GU360246 GU360719 GU360281 GU359516 GU359979 GU359130
81 Muhlenbergia polycaulis Scribn. Peterson 22092 & Saarela (US) Mexico, Chihuahua HM143307 HM143688 HM143589 MK090727 HM143203 HM143101
82 Muhlenbergia porteri Scribn. ex Beal Peterson 19846 & Lara Contreras (US) Mexico, Coahuila HM143308 HM143689 HM143590 HM143405 HM143204 HM143102
83 Muhlenbergia ramosa (Hack. ex Matsum.) Makino Soreng 5302, Peterson & Sun Hang (US) China, Yunnan HM143314 HM143695 HM143595 HM143411 HM143210 HM143108
84 Muhlenbergia romaschenkoi P.M. Peterson Peterson 20331, Soreng & Romashchenko (US) Peru, Huánuco MK090784 MK096270
85 Muhlenbergia schreberi J.F. Gmel. Peterson 19443, Soreng, Salariato & Panizza (US) Argentina, Tucuman GU360214 GU360679 GU360404 GU359456 GU359950 GU359161
86 Muhlenbergia setarioides E. Fourn. Peterson 9897 & Annable (US) Mexico, Oaxaca MK090823 MK090883 MK090853 MK090736 MK090785 MK090697
87 Muhlenbergia sobolifera (Muhl. ex Willd.) Trin. Peterson 20834 & Saarela (US) USA, Virginia HM143324 MK090884 HM143604 HM143420 HM143220 HM143118
88 Muhlenbergia spiciformis Trin. Peterson 22362 & Saarela (US) Mexico, Oaxaca HM143326 HM143706 HM143606 HM143422 HM143222 HM143120
89 Muhlenbergia spiciformis Trin. Peterson 24580, Romaschenko & Valdés-Reyna (US) Mexico, Coahuila MK090786 MK090698
90 Muhlenbergia sylvatica (Torr.) Torr. ex A. Gray Brant 4783 (MO) USA, Missouri MK090824 MK090885 MK090854 MK090738 MK090787 MK090699
91 Muhlenbergia tarahumara P.M. Peterson & Columbus Peterson 22053 & Saarela (US) Mexico, Chihuahua HM143330 HM143710 HM143610 HM143425 HM143226 HM143124
92 Muhlenbergia tenella (Kunth) Trin. Peterson 22141 & Saarela (US) Mexico, Chihuahua HM143331 HM143711 HM143611 HM143227 HM143125
93 Muhlenbergia tenuiflora (Willd.) Britton, Sterns & Poggenb. Peterson 15778 & Saarela (US) USA, Virginia. HM143332 HM143712 HM143612 HM143426 HM143228 HM143126
94 Muhlenbergia tenuifolia (Kunth) Kunth Peterson 22344 & Saarela (US) Mexico, Oaxaca HM143333 HM143713 HM143613 HM143427 HM143229 HM143127
95 Muhlenbergia tenuifolia (Kunth) Kunth Peterson 24462, Romaschenko & Valdés-Reyna (US) Mexico, Coahuila MK090788 MK090700
96 Muhlenbergia tenuifolia (Kunth) Kunth Peterson 24471 & Romaschenko (US) Mexico, Coahuila MK090789 MK090701
97 Muhlenbergia tenuifolia (Kunth) Kunth Peterson 24673 & Romaschenko (US) Mexico, San Luis Potosí MK090825 MK090886 MK090739 MK090790 MK090702
98 Muhlenbergia tenuifolia (Kunth) Kunth Peterson 24730, Romaschenko & Zamudio Ruíz (US) Mexico, Queretaro MK090826 MK090887 MK090740 MK090791 MK090703
99 Muhlenbergia tenuifolia (Kunth) Kunth Peterson 24816, Romaschenko, Rodriguez Avalos, Herrera-Simoni & Garcia Rodriguez (US) Mexico, Aguascalientes MK090827 MK090888 MK090741 MK090792 MK090704
100 Muhlenbergia tenuifolia (Kunth) Kunth Peterson 24847 & Romaschenko (US) Mexico, Zacatecas MK090828 MK090889 MK090855 MK090742 MK090793 MK090705
101 Muhlenbergia thurberi (Scribn.) Rydb. Peterson 5619 & Annable (US) USA, Arizona HM143335 HM143715 HM143615 HM143428 HM143231 HM143129
102 Muhlenbergia uniseta (Lag.) Columbus Peterson 22044 & Saarela (US) Mexico, Chihuahua GU360128 GU360577 GU360278 GU359392 GU360012 GU359260
103 Muhlenbergia uniseta (Lag.) Columbus Peterson 24712, Romaschenko & Zamudio Ruíz (US) Mexico, Queretaro MK090794 MK090706
104 Muhlenbergia uniseta (Lag.) Columbus Peterson 24779, Romaschenko & Zamudio Ruíz (US) Mexico, Queretaro MK090795 MK090707
subg. Pseudosporobolus
105 Muhlenbergia alopecuroides (Griseb.) P.M. Peterson & Columbus Peterson 20960, Saarela, Lara Contreras & Reyna Alvarez (US) Mexico, Coahuila GU360224 GU360688 GU360426 GU359425 GU359976 GU359152
106 Muhlenbergia alopecuroides (Griseb.) P.M. Peterson & Columbus Peterson 22008 & Saarela (US) Mexico, Chihuahua GU360223 GU360687 GU360425 GU359451 GU359975 GU359153
107 Muhlenbergia alopecuroides (Griseb.) P.M. Peterson & Columbus Peterson 24524 & Romaschenko (US) Mexico, Coahuila MK090798 MK090858 MK090831 MK090711 MK090747 MK090660
108 Muhlenbergia alopecuroides (Griseb.) P.M. Peterson & Columbus Peterson 24885 & Romaschenko (US) Mexico, San Luis Potosí MK090799 MK090859 MK090832 MK090712 MK090748 MK090661
109 Muhlenbergia arenacea (Buckley) Hitchc. Peterson 10624 & Annable (US) Mexico, Coahuila GU360210 GU360675 GU360414 GU359452 GU359961 GU359165
110 Muhlenbergia asperifolia (Nees & Meyen ex Trin.) Parodi Peterson 15452, Soreng, Finot & Judziewicz (US) Chile, Region III (Atacama) HM143252 HM143634 HM143539 HM143356 HM143149 HM143048
111 Muhlenbergia atacamensis Parodi Peterson 19626, Soreng, Salariato, & Panizza, (US) Argentina, Jujuy GU360115 GU360595 GU360489 GU359382 GU359879 GU359344
112 Muhlenbergia cuspidata (Torr. ex Hook.) Rydb. Hill 35331 (US) USA HM143260 HM143546 HM143156 HM143055
113 Muhlenbergia fastigiata (J. Presl) Henrard Peterson 21512, Soreng, LaTorre & Rojas Fox (US) Peru, Ancash HM143270 HM143651 HM143556 HM143372 HM143166 HM143064
114 Muhlenbergia implicata (Kunth) Trin. Peterson 22266, Saarela (US) Mexico, Oaxaca HM143283 HM143664 HM143568 HM143385 HM143179 HM143077
115 Muhlenbergia jaime-hintonii P.M. Peterson & Valdés-Reyna Peterson 15841 & Valdes Reyna (US) Mexico, Nuevo León HM143285 HM143665 HM143569 HM143386 HM143181 HM143079
116 Muhlenbergia ligulata (E. Fourn.) Scribn. & Merr. Peterson 22416 & Saarela (US) Mexico, Durango GU360069 GU360551 GU360440 GU359381 GU359863 GU359273
117 Muhlenbergia monandra Alegría & Rúgolo Peterson 17990 & Refulio Rodriguez (US) Peru, Lima GQ397891*
118 Muhlenbergia multiflora Columbus Peterson 7845 & Annable (US) USA, Colorado GU360191 GU360702 GU360289 GU359525 GU359985 GU359138
119 Muhlenbergia palmirensis Grignon & Lægaard Peterson 9317 & Judziewicz (US) Ecuador, Chimborazo HM143305 HM143685 HM143586 HM143402 HM143200 HM143098
120 Muhlenbergia paniculata (Nutt.) Columbus Peterson 12070 & Annable (US) USA, Colorado GU360170 GU360673 GU360375 GU359529 GU359936 GU359201
121 Muhlenbergia paniculata (Nutt.) Columbus Stevens 909 (US) USA MK090814 MK090874 MK090847 MK090726 MK090766
122 Muhlenbergia phleoides (Kunth) Columbus Peterson 24452, Romaschenko & Valdés-Reyna (US) Mexico, Nuevo León MH400231 MH400228
123 Muhlenbergia phleoides (Kunth) Columbus Peterson 24668 & Romaschenko (US) Mexico, San Luis Potosí MK090770 MK090683
124 Muhlenbergia phleoides (Kunth) Columbus Peterson 24717, Romaschenko & Zamudio Ruíz (US) Mexico, Querétaro MK090771 MK090684
125 Muhlenbergia phleoides (Kunth) Columbus Peterson 24731, Romaschenko & Zamudio Ruíz (US) Mexico, Querétaro MK090772 MK090685
126 Muhlenbergia phleoides (Kunth) Columbus Peterson 24799, Romaschenko, Rodriguez Avalos, Herrera-Simoni, & Garcia Rodriguez (US) Mexico, Aguascalientes MH400232 MH400229
127 Muhlenbergia phleoides (Kunth) Columbus Peterson 24938, Romaschenko & González-Elizondo (US) Mexico, Durango KX582659 KX582383
128 Muhlenbergia pungens Thurb. ex A. Gray Ricketson 4642 (MO) USA, Arizona MK090815 MK090875 MH508106 MH508102 MH508098
129 Muhlenbergia repens (J. Presl) Hitchc. Peterson 7900 & Annable (US) USA, New Mexico HM143316 HM143697 HM143596 HM143413 HM143212 HM143110
130 Muhlenbergia repens (J. Presl) Hitchc. Peterson 5735 & Annable (US) USA, Texas HM143338 HM143717 HM143617 HM143430 HM143233 HM143131
131 Muhlenbergia richardsonis (Trin.) Rydb. Peterson 19817, Saarela & Sears (US) USA, California GU360212 GU360677 GU360431 GU359454 GU359978 GU359163
132 Muhlenbergia seatonii Scribn. Peterson 9946 & Annable (US) Mexico, Puebla MK090822 MK090882 MH508107 MK090735 MH508103 MH508099
133 Muhlenbergia spatha Columbus Schaffner 134 (US) Mexico GU359981 MH400230
134 Muhlenbergia subbiflora Hitchc. Peterson 21158, Saarela, Rosen & Reid (US) Mexico, Durango GU360036 GU360518 GU360439 GU359428 GU359877 GU359318
135 Muhlenbergia tenuissima (J. Presl) Kunth Peterson 4751 & Annable (US) Mexico, Jalisco MK090829 MK090890 MH508108 MK090743 MH508104 MH508100
136 Muhlenbergia uniflora (Muhl.) Fernald Peterson 13212, Annable, Pizzolato, Gordon, Frett, Frick, Morrone & Griner (US) USA, New Jersey HM143337 HM143716 HM143616 HM143429 HM143232 HM143130
137 Muhlenbergia uniflora (Muhl.) Fernald Peterson 20862 & Saarela (US) USA, New York GU360258 GU360715 GU360275 GU359463 GU359994 GU359119
138 Muhlenbergia utilis (Torr.) Hitchc. Peterson 24869 & Romaschenko (US) Mexico, San Luis Potosí MH508105 MH508101
139 Muhlenbergia villiflora Hitchc. Peterson 15811 & Valdes Reyna (US) Mexico, Nuevo León HM143340 HM143720 HM143620 HM143431 HM143236 HM143133
140 Muhlenbergia wrightii Vasey ex J.M. Coult. Peterson 20964, Saarela, Lara Contreras & Reyna Alvarez (US) Mexico, Coahuila HM143344 HM143723 HM143623 HM143434 HM143240 HM143137
subg. Trichochloa
141 Muhlenbergia articulata Scribn. Peterson 13386 & Knowles (US) Mexico, San Luis Potosi HM143251 HM143633 HM143538 HM143355 HM143148 HM143047
142 Muhlenbergia breviligula Hitchc. Pohl 13392 & Gabel (MO) Honduras, Santa Bárbara MK090800 MK090860 MK090833 MK090749 MK090662
143 Muhlenbergia capillaris (Lam.) Trin. Peterson 14236, Weakley & LeBlond (US) USA, North Carolina HM143255 HM143638 HM143542 HM143359 HM143152 HM143051
144 Muhlenbergia distichophylla (J. Presl) Kunth Peterson 15913 & Valdes Reyna (US) Mexico, Tamaulipas HM143262 HM143643 HM143548 HM143364 HM143158
145 Muhlenbergia coerulea (Griseb.) Mez Peterson 21703, Soreng, LaTorre & Rojas Fox (US) Peru, Ancash HM143245 HM143627 HM143532 HM143349 HM143142 HM143041
146 Muhlenbergia coerulea (Griseb.) Mez Peterson 21958, Soreng & Montoya Quino (US) Peru, La Libertad HM143246 HM143628 HM143533 HM143350 HM143143 HM143042
147 Muhlenbergia dubia E. Fourn. Peterson 21105 & Saarela (US) Mexico, Nuevo León HM143263 HM143644 HM143550 HM143365 HM143160 HM143057
148 Muhlenbergia durangensis Y. Herrera Peterson 13644, Knowles, Dietrich, Braxton & Gonzalez-Elizondo (US) Mexico, Durango HM143266 HM143647 HM143552 HM143368 HM143162 HM143060
149 Muhlenbergia elongata Scribn. ex Beal Peterson 22164 & Saarela (US) Mexico, Chihuahua HM143267 HM143648 HM143553 HM143369 HM143163 HM143061
150 Muhlenbergia emersleyi Vasey Peterson 22096 & Saarela (US) Mexico, Chihuahua GU360207 GU360672 GU360411 GU359449 GU359958 GU359168
151 Muhlenbergia expansa (Poir.) Trin. Peterson 14234, Weakley & LeBlond (US) USA, North Carolina HM143269 HM143650 HM143555 HM143371 HM143165 HM143063
152 Muhlenbergia gigantea (E. Fourn.) Hitchc. Peterson 22260 & Saarela (US) Mexico, Oaxaca GU360215 GU360680 GU360419 GU359457 GU359966 GU359160
153 Muhlenbergia grandis Vasey Peterson 13413, Knowles, Dietrich & Braxton (US) Mexico, Sinaloa HM143279 HM143660 HM143565 HM143381 HM143175 HM143073
154 Muhlenbergia gypsophila Reeder & C. Reeder Peterson 15840 & Valdes Reyna (US) Mexico, Nuevo León HM143280 HM143661 HM143382 HM143176 HM143074
155 Muhlenbergia iridifolia Soderstr. Peterson 6133 & Annable (US) Mexico, Jalisco HM143284 HM143180 HM143078
156 Muhlenbergia jaliscana Swallen Peterson 6149 & Annable (US) Mexico, Jalisco HM143286 HM143666 HM143570 HM143387 HM143182 HM143080
157 Muhlenbergia lehmanniana Henrard Santamaria 3760 (MO) Colombia MK090673
158 Muhlenbergia lindheimeri Hitchc. Peterson 6280 & Annable (US) USA, Texas HM143290 HM143670 HM143573 HM143391 HM143186 HM143084
159 Muhlenbergia longiglumis Vasey Peterson 13666, Knowles, Dietrich, Braxton & Gonzalez Elizondo (US) Mexico, Durango HM143291 HM143671
160 Muhlenbergia longiligula Hitchc. Peterson 15224 & Cayouette (US) USA, Arizona HM143292 HM143672 HM143574 MK090724 HM143187 HM143085
161 Muhlenbergia lucida Swallen Peterson 22134 & Saarela (US) Mexico, Chihuahua HM143294 HM143674 HM143575 HM143392 HM143188 HM143086
162 Muhlenbergia macroura (Kunth) Hitchc. Peterson 22062 & Saarela (US) Mexico, Chihuahua GU360265 GU360683 GU360409 GU359447 GU359956 GU359125
163 Muhlenbergia maxima Lægaard & Sánchez Vega Peterson 21884, Soreng & Sanchez Vega (US) Peru, Cajamarca HM143296 HM143676 HM143578 MK090725 HM143191 HM143089
164 Muhlenbergia mucronata (Kunth) Trin. Peterson 22038 & Saarela (US) Mexico, Chihuahua HM143302 HM143682 HM143583 HM143399 HM143197 HM143095
165 Muhlenbergia nigra Hitchc. Peterson 16097 & Rosales (US) Mexico, Jalisco HM143303 HM143683 HM143584 HM143400 HM143198 HM143096
166 Muhlenbergia palmeri Vasey Peterson 5478 & Annable (US) USA, Arizona HM143304 HM143684 HM143585 HM143401 HM143199 HM143097
167 Muhlenbergia pubescens (Kunth) Hitchc. Peterson 21250 & Saarela (US) Mexico, Durango HM143310 HM143691 HM143592 HM143406 HM143205 HM143103
168 Muhlenbergia pubigluma Swallen Peterson 15838 & Valdes Reyna (US) Mexico, Nuevo León HM143311 HM143692 HM143593 HM143408 HM143207 HM143105
169 Muhlenbergia purpusii Mez Peterson 6227 & Annable (US) Mexico, San Luis Potosi HM143312 HM143693 HM143594 HM143409 HM143208 HM143106
170 Muhlenbergia reederorum Soderstr. Peterson 21262 & Saarela (US) Mexico, Durango HM143315 HM143696 HM143412 HM143211 HM143109
171 Muhlenbergia reverchonii Vasey & Scribn. Peterson 6285 & Annable (US) USA, Texas HM143317 HM143698 HM143597 HM143414 HM143213 HM143111
172 Muhlenbergia rigens (Benth.) Hitchc. Peterson 22129 & Saarela (US) Mexico, Chihuahua GU360256 GU360729 GU360357 GU359481 GU359951 GU359117
173 Muhlenbergia rigida (Kunth) Kunth Peterson 21637, Soreng, LaTorre & Rojas Fox (US) Peru, Ancash GU360255 GU360718 GU360405 GU359380 GU359952 GU359116
174 Muhlenbergia rigida (Kunth) Kunth Peterson 22061 & Saarela (US) Mexico, Chihuahua HM143319 HM143700 HM143599 HM143416 HM143215 HM143113
175 Muhlenbergia rigida (Kunth) Kunth Peterson 24538 & Romaschenko (US) Mexico, Coahuila MK090818 MK090878 MK090850 MK090730 MK090775 MK090688
176 Muhlenbergia rigida (Kunth) Kunth Peterson 24576, Romaschenko & Valdés-Reyna (US) Mexico, Coahuila MK090819 MK090879 MK090851 MK090731 MK090776 MK090689
177 Muhlenbergia rigida (Kunth) Kunth Peterson 24715, Romaschenko & Zamudio Ruíz (US) Mexico, Queretaro MK090777 MK090690
178 Muhlenbergia rigida (Kunth) Kunth Peterson 24733, Romaschenko & Zamudio Ruíz (US) Mexico, Queretaro MK090778 MK090691
179 Muhlenbergia rigida (Kunth) Kunth Peterson 24802, Romaschenko, Rodriguez Avalos, Herrera-Simoni & Garcia Rodriguez (US) Mexico, Aguascalientes MK090820 MK090880 MK090852 MK090732 MK090779 MK090692
180 Muhlenbergia rigida (Kunth) Kunth Peterson 24805, Romaschenko, Rodriguez Avalos, Herrera-Simoni & Garcia Rodriguez (US) Mexico, Aguascalientes MK090780 MK090693
181 Muhlenbergia rigida (Kunth) Kunth Peterson 24931, Romaschenko & González-Elizondo (US) Mexico, Durango MK090781 MK090694
182 Muhlenbergia rigida (Kunth) Kunth Peterson 24932, Romaschenko & González-Elizondo (US) Mexico, Durango MK090782 MK090695
183 Muhlenbergia rigida (Kunth) Kunth Peterson 24933, Romaschenko & González-Elizondo (US) Mexico, Durango MK090821 MK090881 MK090733 MK090783 MK090696
184 Muhlenbergia robusta (E. Fourn.) Hitchc. Peterson 15928 & Valdes Reyna (US) Mexico, Nuevo Leon HM143320 HM143701 HM143600 MK090734 HM143216 HM143114
185 Muhlenbergia sericea (Michx.) P.M. Peterson Peterson 14843, Blackburn & Peterson (US) USA, South Carolina HM143321 HM143702 HM143601 HM143417 HM143217 HM143115
186 Muhlenbergia setifolia Vasey Peterson 20942, Saarela, Lara Contreras & Reyna Alvarez (US) Mexico, Coahuila HM143322 HM143703 HM143602 HM143418 HM143218 HM143116
187 Muhlenbergia speciosa Vasey Peterson 13616, Knowles, Dietrich, Braxton, & Gonzalez Elizondo (US) Mexico, Durango HM143325 HM143705 HM143605 HM143421 HM143221 HM143119
188 Muhlenbergia stricta (J. Presl) Kunth Peterson 13709 (US) Mexico, Jalisco HM143328 HM143708 HM143608 HM143423 HM143224 HM143122
189 Muhlenbergia subaristata Swallen Peterson 21243 & Saarela (US) Mexico, Durango HM143329 HM143709 HM143609 HM143424 HM143225 HM143123
190 Muhlenbergia venezuelae Luces Briceño 266 & Adamo (MO) Venezuela, Merida MK090830 MK090891 MK090856 MK090746 MK090796 MK090709
191 Muhlenbergia versicolor Swallen Peterson 9913 & Annable (US) Mexico, Oaxaca HM143339 HM143719 HM143619 HM143235 HM143132
192 Muhlenbergia virletii (E. Fourn.) Soderstr. Peterson 9724 & Campos Villanueva (US) Mexico, Oaxaca HM143343 MK090892 MK090857 HM143239 HM143136
193 Muhlenbergia x involuta Swallen Peterson 6284 & Annable (US) USA, Texas HM143345 HM143724 HM143624 HM143435 HM143241 HM143138

Taxonomy

Specimens of Muhlenbergia from Peru were reviewed in the following herbaria: AAU, COL, CPUN, CUZ, F, HAO, K, LIL, LPB, MO, MOL, NY, US and USM. The first author (PMP) travelled and collected 3042 numbers (primarily grasses) while on seven expeditions to Peru between 1997 and 2008. Of these, 258 are collections of Muhlenbergia and all are accounted for here. Synonymy is mainly limited to names of taxa described from South America. Additional synonyms accepted by us can be found in the Catalogue of New World Grasses, vol. II (Peterson et al. 2001) and on the Catalogue of New World Grasses web site (http://www.tropicos.org/Project/CNWG) that is continually updated within TROPICOS (http://www.tropicos.org). When counting culm nodes, it is best to start counting 1 cm above the base. Blade width is measured from margin to margin on a flat blade but not when the blade is tightly involute. Glabrous refers to without pubescence. Smooth indicates no prickle-hairs with broad bases and/or hooked or pointed apices (i.e. pubescence can occur on a smooth surface and a scabrous surface can be glabrous). Excluded species and an infrageneric classification of the accepted species of Muhlenbergia in Peru are presented at the end of the taxonomic treatment.

Results and discussion

Phylogeny

A total of 226 new sequences from 146 species of Muhlenbergia are newly reported in GenBank (Table 1). The following 13 species are new in the phylogeny of Muhlenbergia: M. capillipes (M.E. Jones) P.M. Peterson & Annable, M. ligularis (Hack.) Hitchc., M. flabellata Mez, M. bushii R.W. Pohl, M. diversiglumis Trin., M. frondosa (Poir.) Fernald, M. glabrifloris Scribn., M. romaschenkoi P.M. Peterson, M. setaroides E. Fourn., M. sylvatica (Torr.) Torr. ex A Gray, M. breviligula Hitchc., M. lehmanniana Henrard and M. venezuelae Luces (Peterson et al. 2010b; 2018). Total aligned characters for individual regions and other parameters are noted in Table 2. The plastid−ITS sequences were combined in the analysis except where incongruence between datasets was detected (Fig. 1).

Characteristics of the six regions, rps3, rps16-trnK, rps16 intron, ndhA intron, rpl32-trnL, and ITS, and parameters used in Bayesian analyses indicated by Akaike Information Criterion (AIC).

rps3 rps16-trnK rps16 intron ndhA intron rpl32-trnL ITS Overall
Total aligned characters 615 1000 1088 1189 996 761 5649
Number of new sequences 31 (19.5%) 33 (20.8%) 26 (17.2%) 34 (23%) 48 (25.9%) 50 (26.7%) 222 (22.4%)
Likelihood score (-lnL) 2342.85 3659.76 3429.94 5167.05 4762.52 9632.65
Number of substitution types 6 6 6 6 6 6
Model for among-site rate variation gamma gamma gamma gamma gamma gamma
Substitution rates
rAC 0.90029 1.07678 1.23238 0.75118 1.09619 1.43396
rAG 1.92233 3.01634 1.29662 2.20104 1.87400 2.69229
rAT 0.56014 0.53859 0.46844 0.62199 0.45930 1.81818
rCG 1.67415 1.17251 1.02428 1.66881 1.25539 0.71134
rCT 3.50831 2.22649 2.45667 2.58721 1.47927 5.08729
rGT 1.00000 1.00000 1.00000 1.00000 1.00000 1.00000
Character state frequencies
fA 0.43511 0.31626 0.38612 0.38183 0.38425 0.26145
fC 0.14841 0.12963 0.11052 0.11648 0.11939 0.19766
fG 0.16534 0.13166 0.17725 0.13533 0.12321 0.24978
fT 0.25114 0.42244 0.32611 0.36637 0.37315 0.29111
Proportion of invariable sites 0.19372 0.10382 0.38367 0.07818 0.1631 0.38392
Gamma shape parameter (α) 0.74961 1.26136 0.92705 0.96285 0.93242 0.80871

The Bayesian tree from the combined analysis of ITS and five plastid regions (ndhA intron, rpl32-trnL, rps3, rps16 intron and rps16-trnK) is well resolved with strong support for the monophyly of Muhlenbergia, including M. ramulosa (Kunth) Swallen, sister to M. subg. BealiaM. subg. Trichochloa, these all being in one clade that is sister to M. subg. ClomenaM. subg. Pseudosporobolus and sister to M. subg. Muhlenbergia. (Fig. 1; posterior probability, PP = 0.95−1, shown with thick branches). Each of the five major clades, corresponding to the five subgeneric divisions that have been recognised previously (Peterson et al. 2010b), include species that occur in Peru and/or South America (red) or as wide ranging species from the Americas. The species in each of these five subgenera share salient morphological characteristics or trends.

Species of M. subg. Bealia are strongly caespitose, never rhizomatous, annuals or perennials with pubescent margins or midnerves at least on the lower ½ of the lemma (only M. ligularis is without pubescence) and round, equal primary, secondary and tertiary vascular bundles without well-developed schlerenchyma (Peterson and Herrera Arrieta 2001; Peterson 2003; Peterson et al. 2010b). The Peruvian endemic, M. caxamarcensis Lægaard & Sánchez Vega and the wide-ranging, M. ligularis (Central and South America), are members of this subgenus.

Although the clade of species representing the M. subg. Trichochloa is strongly supported in our analyses (Fig. 1), there is little resolution among members, suggesting very low levels of genetic divergence among the species in this subgenus. The low level of divergence may be a consequence of rapid speciation events. Within Muhlenbergia, this group is by far the most difficult to determine because there are very few morphological differences among the taxa and discrete (nonplastic) characteristics are few. The species of M. subg. Trichochloa consist of robust perennials up to 3 metres tall with compressed-keeled or rounded basal sheaths, 1-veined glumes and unequal rectangular or obovate/elliptic secondary and tertiary vascular bundles with well-developed sclerenchyma girders, these usually with sclerosed phloem (Peterson and Herrera Arrieta 2001; Herrera Arrieta and Peterson 2007, 2017, 2018; Peterson et al. 2010b). In Peru, M. coerulea (Griseb.) Mez, M. coerulea×M. rigida, M. maxima Lægaard & Sánchez Vega (endemic) and M. rigida (Kunth) Kunth are placed in M. subg. Trichochloa.

Species of M. subg. Clomena have 3-veined upper glumes that are often 3-toothed, densely caespitose non-rhizomatous culms with lower leaf sheaths that are often flat and somewhat papery at maturity and lemmas with flexuous awns [only M. jonesii (Vasey) Hitchc. lacks an awn, apex is mucronate] (Reeder and Reeder 1995; Herrera Arrieta 1998; Peterson 2003; Peterson et al. 2010b). The wide-ranging M. peruviana (P. Beauv.) Steud. is the only species of this subgenus that reaches South America, including Peru.

Members of M. subg. Pseudosporobolus usually have plumbeous spikelets, well-developed adaxial and abaxial sclerenchyma in their primary vascular bundles, narrow to loosely open panicles, unawned, mucronate or short-awned lemmas [long-awned in M. implicata (Kunth) Trin. and M. seatonii Scribn.] and the plants are rhizomatous when perennial (Peterson and Herrera Arrieta 2001; Peterson 2003; Peterson et al. 2010b). In Peru, M. fastigiata (J. Presl) Henrard, M. monandra Alegría & Rúgolo (endemic) and M. phalaroides (Kunth) P.M. Peterson are placed in M. subg. Pseudosporobolus.

Morphologically, species of the M. subg. Muhlenbergia clade have broad, flat leaf blades, most have well-developed, scaly and creeping rhizomes and panicles that are usually narrow at maturity (Peterson et al. 2010b). This is the only subgenus where the PCK subtype of C4 photosynthesis has been found. PCK species contain chlorenchyma composed of tabular cells that are indistinctly radiate and continuous between bundles [PCK type, defined as centrifugal/evenly distributed photosynthetic carbon reduction (PCRD) cell chloroplasts (with grana). The major veins are surrounded by two bundle sheaths, an inner mestome sheath of elongate non-chlorenchymatous cells and an outer chlorenchymatous sheath of shorter PCRD cells (designated XyMS+structural type; Hattersley and Watson 1976, 1992; Dengler et al. 1986). In addition, the leaf blades of these species contain fan- to shield-shaped bulliform cells that do not form a column of colourless cells from the adaxial to the abaxial surface and they generally have four or more secondary and/or tertiary vascular bundles between consecutive primary vascular bundles (Gutierrez et al. 1974; Brown 1977; Peterson and Herrera Arrieta 2001). Anatomically, Muhlenbergia tarahumara P.M. Peterson & Columbus is an exception to the standard PKC-type leaf structure in having non-contiguous chlorenchyma separated by columns of colourless cells between adjacent vascular bundles (Peterson and Columbus 2009; Peterson et al. 2010b). In Peru, M. beyrichiana Kunth, M. bryophilus (Döll) P.M. Peterson, M. cenchroides (Humb. & Bonpl. ex Willd.) P.M. Peterson, M. ciliata (Kunth) Trin., M. diversiglumis, M. flexuosa Hitchc. (endemic), M. microsperma (DC.) Kunth and M. romaschenkoi (endemic) are placed in M. subg. Muhlenbergia.

Taxonomic treatment

Muhlenbergia Schreb., Gen. Pl. 1: 44. 1789.

Dilepyrum Michx., Fl. Bor.-Amer. 1: 40. 1803. Type: Dilepyrum minutiflorum Michx. (= Muhlenbergia schreberi J. F. Gmel.).

Aegopogon Humb. & Bonpl. ex Willd., Sp. Pl. 4 (2): 899. 1805 [1806] Type: Aegopogon cenchroides Humb. & Bonpl. ex Willd. [≡ Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P.M. Peterson].

Podosemum Desv., Nouv. Bull. Sci. Soc. Philom. Paris 2: 188. 1810. Type: Podosemum capillare (Lam.) Desv. [= Muhlenbergia capillaris (Lam.) Trin.].

Clomena P. Beauv., Ess. Agrostogr. 28. 1812. Type: Clomena peruviana P. Beauv. [≡ Muhlenbergia peruviana (P. Beauv.) Steud.].

Tosagris P. Beauv., Ess. Agrostogr. 29. 1812. Type: Tosagris agrostidea P. Beauv. [= Muhlenbergia capillaris (Lam.) Trin.].

Trichochloa P. Beauv., Ess. Agrostogr. 29. 1812. Type: Trichochloa purpurea P. Beauv. [= Muhlenbergia expansa (Poir.) Trin.].

Podosaemum Kunth, Mem. Mus. Hist. Nat. 2: 72. 1815; orth. var. Podosemum.

Hymenothecium Lag., Gen. Sp. Pl. 4. 1816. Lectotype: Cynosurus tenellus Cav. ex DC., designated by Hitchcock 1920: 169 [≡ Lamarckia tenella DC. ≡ Hymenothecium tenellum (Cav. ex DC.) Lag. = Muhlenbergia uniseta (Lag.) Columbus].

Lycurus Kunth, Nov. Gen. Sp. 1: 141. 1815 [1816]. Lectotype: Lycurus phleoides Kunth, designated by Hitchcock 1920: 139 [≡ Muhlenbergia phleoides (Kunth) Columbus].

Anthipsimus Raf., J. Phys. Chim. Hist. Nat. Arts 89: 105. 1819. Type: Anthipsimus gonopodus Raf. (= Muhlenbergia schreberi J.F. Gmel.).

Sericrostis Raf., Neogenyton 4. 1825. Lectotype: Stipa sericea Michx, designated by Pfeiffer 1874: 1142 [≡ Muhlenbergia sericea (Michx.) P.M. Peterson].

Pereilema J. Presl, Reliq. Haenk. 1 (4–5): 233.1830. Type: Pereilema crinitum J. Presl (≡ Muhlenbergia pereilema P.M.Peterson).

Epicampes J. Presl, Reliq. Haenk. 1 (4–5): 235. 1830. Type: Epicampes stricta J. Presl [= Muhlenbergia robusta (E. Fourn.) Hitchc.].

Dactylogramma Link, Hort. Berol. 2: 248. 1833. Type: Dactylogramma cinnoides Link [= Muhlenbergia glomerata (Willd.) Trin.].

Calycodon Nutt., Proc. Acad. Nat. Sci. Philadelphia 4: 23. 1848. Type: Calycodon montanum Nutt. [≡ Muhlenbergia montana (Nutt.) Hitchc.].

Pleopogon Nutt., Proc. Acad. Nat. Sci. Philadelphia 4: 25. 1848. Type: Pleopogon setosum Nutt. [≡ Lycurus setosus (Nutt.) C.G. Reeder = Muhlenbergia alopecuroides (Griseb.) P.M. Peterson & Columbus].

Schedonnardus Steud., Syn. Pl. Glumac. 1: 146. 1854. Type: Schedonnardus texanus Steud. [Spirochloe paniculata Nutt. = Schedonnardus paniculatus (Nutt.) Branner & Coville = Muhlenbergia paniculata (Nutt.) Columbus].

Vaseya Thurb., Proc. Acad. Nat. Sci. Philadelphia 15: 79. 1863. Type: Vaseya comata Thurb. [= Muhlenbergia andina (Nutt.) Hitchc.].

Chaboissaea E. Fourn., Mexic. Pl. 2: 112. 1886. Type: Chaboissaea ligulata E. Fourn. [≡ Muhlenbergia ligulata (E. Fourn.) Scribn. & Merr.].

Crypsinna E. Fourn., Mexic. Pl. 2: 90. 1886. Lectotype: Crypsis macroura Kunth, designated by Hitchcock 1920: 144. [≡ Crypsinna macroura (Kunth) E. Fourn.≡ Muhlenbergia macroura (Kunth) Hitchc.].

Redfieldia Vasey, Bull. Torrey Bot. Club 14: 133. 1887. Type: Graphephorum flexuosum Thurb. ex A. Gray [≡ Redfieldia flexuosa (Thurb. ex A. Gray) Vasey ≡ Muhlenbergia multiflora Columbus].

Bealia Scribn., True Grasses 104, f. 45a. 1890. Type: Bealia mexicana Scribn. (≡ Muhlenbergia biloba Hitchc.).

Blepharoneuron Nash, Bull. Torrey Bot. Club 25(2): 88. 1898. Lectotype: Vilfa tricholepis Torr., designated by Peterson and Annable 1990: 522 [≡ Blepharoneuron tricholepis (Torr.) Nash ≡ Muhlenbergia tricholepis (Torr.) Columbus].

Schaffnerella Nash, N. Amer. Fl. 17(2): 141. 1912. Type: Schaffnera gracilis Benth. [≡ Schaffnerella gracilis (Benth.) Nash ≡ Muhlenbergia spatha Columbus].

Description

Plants annual or perennial; synoecious sometimes andromonoecious; sometimes rhizomatous, often cespitose, sometimes mat-forming, rarely stoloniferous. Culms 2–300 cm, erect, geniculate or decumbent, usually herbaceous, sometimes becoming woody. Sheaths open, overlapping below; ligules membranous or hyaline (rarely firm or coriaceous), acuminate to truncate, sometimes minutely ciliolate, sometimes with lateral lobes longer than the central portion; blades narrow, flat, folded, or involute, sometimes arcuate. Inflorescences terminal, sometimes also axillary, open to contracted, raceme-like or spike-like panicles; cleistogamous panicles sometimes present in the axils of the lower cauline leaves, enclosed by a tightly rolled, somewhat indurate sheath; disarticulation usually above the glumes, occasionally below the pedicels. Spikelets mostly perfect with 1 (2–6) florets, sometimes staminate or sterile, occasionally paired or in groups of threes then the central spikelet perfect and the lateral ones staminate or sterile; chasmogamous, rarely cleistogamous; glumes usually (0)1(2–3)-veined, apices entire, erose or toothed, truncate to acuminate, sometimes mucronate or awned from the midvein, occasionally awned from the lateral veins; lower glumes sometimes rudimentary or absent, occasionally bifid; upper glumes shorter than to longer than the florets; calluses poorly developed, glabrous or with a few hairs; lemmas glabrous, scabrous or with short hairs, 3-veined (rarely appearing 5-veined), apices awned from the midvein, mucronate or unawned; awns, if present, straight, flexuous, sinuous or curled, sometimes borne between 2 minute teeth, lateral veins occasionally extended into awns; paleas shorter than or equal to the lemmas, 2-veined, apices; anthers (1–2)3, purple, orange, yellow, olivaceous or whitish; ovary with 2 styles, stigmas plumose. Caryopses elongate, fusiform or elliptic, slightly dorsally compressed, rarely laterally compressed, glabrous; hilum short; pericarp fused.

Chromosome base number is × = (8 or 9) 10 and these are relatively small in size.

Distribution

The genus is primarily distributed in the Western Hemisphere in North Central and South America. There are also seven species known to occur in south-eastern Asia, six of these are found in China (Wu and Peterson 2006).

Ecology

The species occur in open habitats in deserts, grasslands, sclerophllous scrubland and margins of forests often in xeric to meso-xeric habitats from near sea level to more than 4000 m.

Etymology

Named for Gotthilf Heinrich Ernst Muhlenberg (1753–1815), a Lutheran minister and pioneering botanist of Pennsylvania, USA.

Key to the species of Muhlenbergia in Peru

1 Spikelets grouped in fascicles of 2−4 spikelets 2
Spikelets not grouped in fascicles 5
2 Each fascicle subtended by 10−15 bristles, the bristles 1−5 mm long; ligules auriculate, the auricles 1−2 mm long, ciliate, sometimes cauducous at maturity, the cilia about 1 mm long 1. M. beyrichiana
Fascicles never subtended by bristles; ligules not auriculate and not ciliate or hairy 3
3 Anthers 0.5−0.7 mm long; sprawling, slender annuals (4–) 6–30 cm long; sessile or inconspicuously pedicelled perfect spikelet associated with one (rarely two) staminate or sterile pedicelled spikelets 2. M. bryophilus
Anthers 1.6−2 mm long; sprawling perennials, 10–55 cm long; sessile or inconspicuously pedicelled spikelet perfect and associated with two staminate or sterile pedicelled spikelets or the lower short-pedicelled spikelet perfect, staminate or sterile and the upper longer-pedicelled spikelet perfect, staminate or sterile 4
4 Apex of lemmas 3-awned, the central awns 5−13 mm long, lateral awns 2–3 mm long; lemmas 2.5–3 mm long with glabrous margins; lower glumes 1-veined, apex deeply notched with triangular lobes 4. M. cenchroides
Apex of lemmas 1-awned, sometimes mucronate or unawned, the awns 1−3 mm long; lemmas 3−4 mm long with hirsute to lanate margins, the hairs 0.1−0.3 mm long; lower glumes commonly 2 or 3-veined, usually 2-awned (from lateral veins), apex not deeply notched and without triangular lobes 16. M. phalaroides
5 Plants annual 6
Plants perennial 13
6 Upper glumes 3-veined, the apex broad and truncate, usually 2- or 3-toothed 15. M. peruviana
Upper glumes 1-veined, the apex acute, acuminate, or subulate, not 2- or 3-toothed 7
7 Lemmas mucronate, the mucro usually less than 1 mm long or occasionally short-awned with the awn up to 1.5 mm long 8
Lemmas awned, the awns 1.2−30 mm long, at least some of the spikelets with awns much longer than 1.2 mm 9
8 Lemmas sericeous, lower ½−¾ with scattered hairs, the hairs 0.3−0.5 mm long; paleas hairy between the nerves 3. M. caxamarcensis
Lemmas glabrous; paleas glabrous between the nerves 11. M. ligularis
9 Florets with a single stamen; panicles 2−9 mm wide, tightly spiciform; lemma awns 1.2−5 mm long; both glumes as long or longer than the floret 14. M. monandra
Florets with 3 stamens; panicles 1.8−13.5 cm wide, sometimes narrow or contracted when immature but with spreading or reflexed branches at maturity; lemma awns 5−30 mm long; both glumes not longer than the floret (lower glume longer in M. diversiglumis) 10
10 Cleistogamous panicles with 1–3 spikelets present in the axils of the lower sheaths; glume apices obtuse, unawned 13. M. microsperma
Cleistogamous panicles not present in the axils of the lower sheaths; glume apices acute to acuminate and usually awned 11
11 Panicles secund; primary branches with 2–5 spikelets; secondary branches not developed; spikelets dimorphic with respect to the glumes, the glumes of the proximal spikelet on each branch subequal, to 0.7 mm long, orbicular and unawned, those of the distal spikelets evidently unequal, the lower glumes to 8 mm long and usually awned, the upper glumes orbicular, sometimes awned 8. M. diversiglumis
Panicles not secund; primary branches always with more than 2 spikelets, usually with more than 5; secondary branches well-developed; spikelets monomorphic with respect to the glumes 12
12 Ligules 0.2−0.8 mm long, apex truncate, entire; paleas glabrous between the nerves on the proximal ½; 6−13 nodes along the panicle; panicles 4−12 cm long 5. M. ciliata
Ligules 1.2−3.0 (−5.0) mm long, acute to obtuse, lacerate; paleas sparsely appressed pubescent between the nerves on the proximal ½; 15−23 nodes along the panicle axis; panicles 7−15 cm long 18. M. romaschenkoi
13 Culms 40−140 cm tall; leaf blades 12−45 cm long 14
Culms 2−40 cm tall; leaf blades 0.3−12 cm long 15
14 Panicles contracted and spike-like, 0.6−2 cm wide, usually plumbeous to reddish-purple; panicle branches tightly ascending from the rachises at maturity 6
Panicles loosely contracted to loosely spreading, (2−) 3−6 (−15) cm wide; panicle branches ascending and/or spreading up to 80° from the rachises 17
16 Glumes (4−) 5−7 (−8) mm long, usually as long or longer than the floret; lemmas unawned, mucronate or short-awned, the awns 1−3(−4) mm long 6. M. coerulea
Glumes 2.5−3.5 (−4) mm long, 1/2−3/4 as long as the floret; lemmas awned, the awns generally 3−8(−10) mm long 7. M. coerulea × M. rigida
17 Lemmas 2.5−2.8 mm long with scattered sericeous hairs along the veins above the hairy callus; caryopses 1.4−1.7 mm long 12. M. maxima
Lemmas 3.5−6 mm long, glabrous along the veins above the hairy callus; glumes caryopses 2−3.5 mm long 18
18 Lemmatal awns 3−8 (−10) mm long; glumes ½−¾ as long as the floret, 2.5−3.5 (−4) mm long; lemmas 4−6 mm long; spikelets plumbeous to reddish-purple 7. M. coerulea × M. rigida
Lemmatal awns (8−) 10−22 mm long; glumes less than ½ as long as the floret, 1−1.7 (−2) mm long; lemmas 3.5−5 mm long; spikelets reddish-purple 17. M. rigida
15 Lemmas awned, the awns 14−30 mm long 19
Lemmas unawned, mucronate, the mucro usually less than 1 mm long or occasionally short-awned with an awn up to 3 mm long 20
19 Lower glumes 2.8−4 mm long including the mucro or short-awn if present; ligules 0.3−0.5 mm long, apex truncate; anthers 1.3−1.6 mm long 10. M. flexuosa
Lower glumes 1−2.5 mm long including the mucro if present; ligules 1.2−3 (−5.0) mm long, apex acute; anthers 0.3−0.4 mm long 18. M. romaschenkoi
20 Lower glumes commonly 2 or 3-veined and awned from the lateral veins, the 2 awns 1−3 mm long; spikelets paired on a branch, the lower spikelet staminate or sterile and the upper perfect 16. M. phalaroides
Lower glumes 1-veined and unawned; spikelets borne singly on a branch or, if in pairs, the upper and lower both perfect 21
21 Plants rhizomatous, the main root or rhizome 1−2 (−2.5) mm wide; leaf blades tightly involute, arcuate, apex often pungent, the blades 2−8.5 mm long long 9. M. fastigiata
Plants not rhizomatous, the roots less than 0.8 mm wide; leaf blades usually flat, straight, not pungent, the blades 3−22 mm long 22
22 Lemmas sericeous, lower ½−¾ with scattered hairs, the hairs 0.3−0.5 mm long; paleas hairy between the veins 3. M. caxamarcensis
Lemmas glabrous; paleas glabrous between the veins 11. M. ligularis

Muhlenbergia beyrichiana Kunth, Enum. Pl. 1: 200. 1833.

Fig. 2A−F

Pereilema beyrichianum (Kunth) Hitchc., Contr. U.S. Natl. Herb. 24(8): 385. 1927. Type: Brazil, Province de Saint-Paul, Voyage d’Auguste de Saint-Hilaire de 1816 a 1821, Saint-Hilare Cat. B #1028 (lectotype, designated here: P-00751689!; isolectotype: US-1645654! ex P).

Description

Caespitose annuals. Culms 30−80 cm tall, slender, terete, glabrous, often branching from the aereal nodes below, usually with stilt-roots from lower nodes. Leaf sheaths usually shorter than the internodes, furrowed, scabrous; ligules 0.5−0.7 mm long, membranous; auricles 1−2 mm long, ciliate, sometimes cauducous at maturity, the cilia about 1 mm long; blades 8−20 cm long, 3−6 (−8) mm wide, flat, scabrous, apex attenuate. Panicles 5−16 (−20) cm long, 1−2.5 cm wide, contracted, spike-like, interrupted, the branches widely spaced along the rachis; primary branches 1−3 cm long, appressed, ascending or divergent and spreading. Spikelets in dense clusters of 2−4 subtended by 10−15 bristles, the bristles 1−5 mm long; glumes 0.7−1 mm long, ovate, membranous, 1-veined, apex awned, bidentate, the awns 3.5−5 mm long; lemmas (1.2−) 2−2.2 mm long, lanceolate, 3-veined, cartilaginous, scaberulous, awned, the awns 10−16 (−20) mm long, straight; callus short, the hairs 0.2−0.4 mm long; paleas as long as the lemmas, 2-veined, these often extending into mucros 0.1−0.3 mm long; stamens 3, anthers 0.7−1 mm long, purplish. Caryopses 1−1.3 mm long, ellipsoid.

Figure 2. 

A−E Muhlenbergia beyrichiana Kunth A habit B ligule with auricles C glumes D floret E stamens and pistil F−H Muhlenbergia maxima Lægaard & Sánchez Vega F habit G end of panicle branch H floret. A−E drawn from A.S. Hitchcock 20635 (US) F−H drawings from Lægaard & Sánchez Vega (1990) drawn from the holotype collection Sánchez Vega & Ruíz Vigo 3561.

Distribution

Muhlenbergia beyrichiana is known to occur in Brazil, Ecuador and Peru. Earlier, it was reported in Mexico and Central America but these are probably an error for Muhlenbergia diandra (R.W. Pohl) Columbus, a more recently described species that superficially resembles M. beyrichiana (Espejo Serna et al. 2000; Lægaard and Peterson 2001; Peterson et al. 2001).

Ecology

This species occurs in xerophilic savannahs with Cactaceae, roadsides and along moist ravines; 150−2000 m (Lægaard and Peterson 2001).

Comments

Muhlenbergia beyrichiana is morphologically similar to M. pereilema P.M. Peterson, which does not occur in Peru, but can be separated from the latter in having interrupted panicles with divergent primary branches (versus uninterruped panicles with tightly appressed primary branches in M. pereilema), straight lemma awns (versus flexuous or wavy), wide leaf blades 3−6 (−8) mm (versus 2−3 mm) and ciliate auricles (versus not ciliate) [Lægaard and Peterson 2001].

Muhlenbergia beyrichiana is in a clade with M. pereilema and M. plumiseta and is sister to M. flexuosa Hitchc. in M. subg. Muhlenbergia (Fig. 1B; Peterson et al. 2010b).

Specimens examined

Peru. Junín: Huancayo, abajo de Pariahuanca, 2000 m, 5 May 1979, Tovar 7880 (US, USM), Tovar 7901 (USM).

Muhlenbergia bryophilus (Döll) P.M. Peterson, Caldasia 31(2): 279, f. 2 A–B, 2009.

Fig. 3A, B

Aegopogon bryophilus Döll, Fl. Bras. 2(3):239. 1880. Type: BRAZIL, Minas Gerais, 10 Apr 1879, A.F.M. Glaziou 11661 (holotype: P-01863266 [image!]; isotypes: C-10016716 [image!], K-000309079 [image!], US-1280026!).

Aegopogon geminiflorus var. muticus Pilg., Bot. Jahrb. Syst. 27(1–2):25. 1899. Type: Bolivia, La Paz, near Sorata, 1 May 1892, M. Bang 1307 (holotype: unknown; isotypes: CM-0179 [image!], K-000309080 [image!], NDG-07662 [image!], PUL-00000320 [image!], US-2473254!; W-18930005256 [image!]).

Aegopogon argentinus Mez, Repert. Spec. Nov. Regni Veg. 17(8−12):145. 1921. Type: ARGENTINA. Salta: Sierra Nevada del Castillo, P.G. Lorentz & G. Hieronymus 182 (holotype: B?; isotypes: BAA-00001256 [image!], US-75037 fragm. ex B!).

Aegopogon fiebrigii Mez, Repert. Spec. Nov. Regni Veg. 17(8−12):145. 1921. Type: BOLIVIA. Camacho, K. Fiebrig 2865 (holotype: B?; isotypes: MVFA-0000127 [image!], US-75308 fragm. ex B!).

Description

Slender often sprawling, caespitose annuals. Culms (4–) 6–30 cm long, glabrous below the nodes; internodes 0.6–6 cm long, glabrous to pilose. Leaf sheaths mostly 0.5–4.8 cm long, shorter than the internodes, glabrous to sparingly pilose; ligules 0.6–1.5 mm long, glabrous, apex mostly truncate, lacerate, auricles absent; blades 1.5–6 cm long, 0.5–1.5(–1.7) mm wide, flat, scaberulent and pubescent above, mostly smooth beneath. Panicles 2–6 cm long, 0.5–1.2 cm wide, open, loosely-flowered; primary branches 0.2–0.6 mm long, excluding the awns, one per node, racemosely inserted. Fertile spikelets 2.4–3 mm long, in fascicles of two, rarely three per branch, often greenish or purplish, the clusters with one short-pedicelled spikelet (bisexual); pedicels (0.0−) 0.2–0.5 mm long (fertile spikelets) and the other two spikelets (sterile or staminate) longer pedicelled; pedicels about 0.7–1 mm long (sterile or staminate); glumes 1–1.3 mm long, narrowly acuminate, apex prolonged, aristate; lemmas 2.4–3 mm long, 3-awned, the central awns (3–) 5–8 (–12) mm long, lateral awns usually 0.8–1.4 mm long; paleas 2.2–2.8 mm long, puberulent, apex aristate, the awns usually 1–1.2 mm long; anthers 0.5–0.7 mm long, yellowish. Caryopses about 1 mm long, obovoid, light brownish.

Figure 3. 

A, B Muhlenbergia bryophilus (Döll) P. M. Peterson A habit B spikelet C, D Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P. M. Peterson C habit D spikelet. Drawings from Giraldo-Cañas and Peterson (2009) A, B drawn from S.G. Beck 818 (LPB) C, D drawn from S.G. Beck 7464 (LPB).

Distribution

Muhlenbergia bryophilus is found in South America, occuring in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador and Peru.

Ecology

This species occurs on moist slopes, cliffs, barrancas, canyons, roadsides and along or near springs usually in shaded areas associated with Cenchrus clandestinus (Hochst. ex Chiov.) Morrone, Bouteloua simplex Lag., Festuca myruos L., Urochloa, Veronica, Eragrostis, Baccharis, Salvia, Agave and Erodium; 1500–3700 m. Flowering December through May.

Comments

Muhlenbergia bryophilus is morphologically similar to M. cenchroides and can be separated from the latter in having anthers 0.5−0.7 mm long, the annual habit with culms (4–) 6–30 cm tall and sessile or inconspicuously pedicelled perfect spikelet associated with one (rarely two) staminate or sterile pedicelled spikelet (Tovar 1993; Giraldo-Cañas and Peterson 2009). The central lemmatal awn length of the sessile or inconspicuously pedicelled spikelet was used by Beetle (1948) to differentiate between these two species but we found this measure to be completely overlapping. Muhlenbergia bryophilus is sister to a single entry of M. uniseta (Peterson 24712) in our new analysis (Fig. 1B). We have only a single marker (ITS) for M. bryophilus, so its alignment may change with additional plastid markers.

Specimens examined

Peru. Cusco: Prov. Anta, Mollepata−Takawana, C. Vargas C. 19050 (USM); Prov. Urubamba, SW facing slope of Machu Picchu Mountain, V. Ugent 5324 (USM); Junín: Prov. Huancayo, Abajo de Pariahuanca, O. Tovar 7895, 7904 (USM); Cerro E of Huancayo, O. Tovar 2137 (USM); La Libertad: Prov. Bolivar, W of Longotea, 0.5 km towards San Vicente, 7°2'35.6"S, 77°52'39.8"W, 3202 m, 31 Mar 2008, P.M. Peterson 21966, R.J. Soreng & J. Montoya Quino (US, USM); Lima: Prov. Canta, 8 km SW of San Jose Canta towards Huamantango, 11°31'10"S, 76°42'16.3"W, 2770 m, 28 Mar 2004, P.M. Peterson & N. Refulio Rodríguez 17995 (US, USM); Piura: Prov. Huancabamba, La Beatita, S. Llatas Quiroz 1850, 1851 (CPUN); Puno: Prov. Sandia, Debajo de Cuyocuyo, R. Ferreyra & A. Vera Beuner 16636 (USM).

Muhlenbergia caxamarcensis Lægaard & Sánchez Vega, Nordic J. Bot. 10:437. 1990.

Fig. 4A−C

Type

Peru, Cajamarca, Micuypampa, 62 km from Cajamarca towards Celendín, 3600 m, 26 Mar 1988, S.A. Renvoize & S. Lægaard 4962 (holotype: CPUN!; isotypes: AAU!, K!, MO-3712393!, US-3185350!).

Description

Loosely caespitose perennials. Culms 8−12 cm tall, 0.2−0.4 mm diameter just below the panicle, erect to decumbent near base, slender, scaberulous to glabrous, profusely branched below; lower internodes 5−10 mm long with repeated intravaginal branching. Leaf sheaths 4−27 mm long, glabrous, generally longer than the internodes, rounded near base; ligules (1.5−) 1.8−2.5 mm long, hyaline, often lacerate, margins decurrent, apex obtuse; blades 0.5−1.5 cm long, 0.6−1.2 mm wide, flat or folded, prominently veined, sometimes conspicuously crystalline or spiculate on both surfaces, otherwise glabrous below, sparsely scaberulous above and along margins, tapering to a boat shaped tip. Panicles (1.0−)1.5−4.0 cm long, 1−3 mm wide, exserted or included in the uppermost sheath, loosely contracted, narrow; primary branches 0.5−2 cm long, appressed to the culm axis, one per node.pedicels 1−5 mm long, stiff, densely scabrous, spiculate, erect; nodes 4−6 per inflorescence. Spikelets 2.4−2.8 mm long (excluding the mucro or awn), plumbeous to reddish-purple; glumes 1.2−1.6 mm long, shorter than the floret, subequal to equal, 1-nerved, glabrous, often reddish-purple near apex and greenish-grey below, apex obtuse; lemmas 2.4−2.8 mm long, lanceolate, keeled, prominently 3-nerved, dark reddish-purple to plumbeous above greenish-grey below, sericeous, lower ½ to ¾ with scattered appressed hairs, the hairs 0.3−0.5 mm long, apex acuminate, mucronate or short-awned, the awn up to 1.5 mm long, scabrous; paleas 2.4−2.6 mm long, as long as the lemma, lanceolate, hairy between the nerves; anthers 1−1.3 mm long, purple or yellow. Caryopses 0.9−1.1 mm long, elliptic to fusiform, terete, yellowish-brown.

Figure 4. 

A−C Muhlenbergia caxamarcensis Lægaard & Sánchez Vega A habit B panicle branch C floret D−G Muhlenbergia ciliata (Kunth) Trin D habit E ligule F glumes G floret. Drawings A−C from Lægaard and Sánchez Vega (1990) from holotype collection (S.A. Renvoize & S. Lægaard 4962) D−G from Peterson and Annable (1991) drawn from P.M. Peterson & C.R. Annable 4541 (WS).

Distribution

This species is endemic to Peru, known only from Cajamarca and La Libertad departments.

Ecology

Muhlenbergia caxamarcensis occurs on shallow soils on rock shelves and rocky outcrops often of calcareous origins, mud flats, open grassy meadows and slopes associated with Festuca, Carex, Calamagrostis (probably better treated as Cinnagrostis Griseb. but combinations are not yet made; Saarela et al. 2017, Soreng et al. 2017), Polylepis, Muhlenbergia ligularis, M. peruviana and M. cenchroides; 3000−3600 m. Flowering March through May.

Comments

Muhlenbergia caxamarcensis is morphologically similar to M. ligularis and M. fastigiata and can be separated from both of these species in possessing sericeous florets (lemma and palea) with hairs readily visible under 10× magnification.

Muhlenbergia caxamarcensis is a member of M. subg. Bealia and is sister to the North American M. filiformis (Thurb. ex S. Watson) Rydb.– M. vaginata Swallen pair (Peterson et al. 2010b). In our new analysis, M. caxamarcensis appears to have evolved within M. ligularis (Fig. 1A, plastid only). However, the ITS marker clearly aligns M. caxamarcensis with a single accession of M. ligularis (Fig. 1A). This pair is sister to M. filiformis and all three accessions are sister to M. vaginata. These results suggest multiple origins for M. caxamarcensis from North and South American progenitors.

Specimens examined

PERU. Cajamarca: Prov. Cajamarca, 16 km W of Cajamarca up road (Avenida Peru) towards Cumbemayo, 3440 m, 31 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 14010 (US, USM); 18 km W of Cajamarca up road (Avenida Peru) towards Cumbe Mayo, 3600 m, 31 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 14013 (US, USM); 29 km from Cajamarca on road to Celendín, S.A. Renvoize & S. Lægaard 4974 (AAU, CPUN, K, US); Cumbe Mayo, I. Sánchez Vega & W. Ruiz Vigo 598 (CPUN), I. Sánchez Vega 4690 (CPUN); Cumbe Mayo, W of Cajamarca, S.A. Renvoize 5000, 5004 & 5005 S. Lægaard & I. Sánchez Vega (AAU, CPUN, K, US); Micuypampa, 62 km from Cajamarca towards Celendín, S.A. Renvoize & S. Lægaard 4961 (AAU, CPUN, K, US); Prov. San Miguel, 61 km N of Cajamarca on hwy 3N towards Bambamarca, 3640 m, 16 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14916 (CPUN, US, USM); Cajamarca to Celendín, 3 km NE of Encañada, I. Sánchez Vega 2777, V. Torrel & E. Medina (CPUN); S.A. Renvoize & S. Lægaard 4849 (CPUN). La Libertad: Prov. Bolivar, 3 air km ESE of Longotea on road to Bolivar, 3202 m, 31 Mar 2008, P.M. Peterson 21965, R.J. Soreng & J. Montoyo Quino (US, USM); Nevado Cajamarquilla, 3500 m, 9 Sep 1946, J. Infantes Vera 937 (MOL).

Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P.M. Peterson, Caldasia 31(2): 280, f. 2 C–D. 2009.

Fig. 3C, D

Aegopogon cenchroides Humb. & Bonpl. ex Willd., Sp. Pl. 4(2):899. 1806. Type: Venezuela, Sucre, Cumaná, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: B-W-01637-020 [image!]; isotypes: P!, US-75957 fragm. ex P!).

Aegopogon geminiflorus Kunth, Nov. Gen. Sp. (quarto ed.) 1:133, t. 43. 1815 (1816). Aegopogon cenchroides var. geminiflorus (Kunth) Griseb., Abh. Königl. Ges. Wiss. Göttingen 24:301. 1879. Type: Venezuela, Amazonas, inter Cerro Duida et Rio Tamatama, juxta Esmeralda, May, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P; isotype: US-75956 fragm. ex P!).

Hymenothecium quinquesetum Lag., Gen. Sp. Pl. 4. 1816. Aegopogon quinquesetus (Lag.) Roem. & Schult., Syst. Veg. 1:805. 1817. Type: Mexico, México Iperio, Ludovicus Nee (holotype: MA; isotype: BAA-00002156 [image!]).

Hymenothecium trisetum Lag., Gen. Sp. Pl. 4. 1816. Aegopogon trisetus (Lag.) Roem. & Schult., Syst. Veg. 2:805. 1817. Aegopogon cenchroides var. trisetus (Lag.) E. Fourn., Mexic. Pl. 2:72. 1886. Type: Mexico, México Imperio (holotype: MA; isotype: BAA-00002158 [image!]).

Aegopogon setifer Nees, Linnaea 19(6):691. 1847. Type: Mexico, A. Aschenborn 132 (holotype: B; isotypes: FR-0036375 [image!], FR-0036376 [image!], US-75953 fragm. ex B!).

Aegopogon cenchroides var. multisetus E. Fourn., Mexic. Pl. 2: 72. 1886. Type: Mexico, Moran. in rupibus, 1840, H. Galeotti 5808 (lectotoype: BR, designated by P.M. Peterson, Contr. U.S. Natl. Herb. 41: 10. 2001; isolectotypes: P!, US-75958 fragm. ex P!).

Description

Caespitose perennials often sprawling, occasionally with stolons. Culms (10–) 25–55 cm long, glabrous below the nodes; internodes glabrous. Leaf sheaths mostly 0.8–8 cm long, shorter than the internodes, glabrous; ligules 1–2 mm long, apex acute, lacerate; blades 1.5–6 cm long, 0.5–2 mm wide, flat, scaberulous above, smooth beneath. Panicles 2–8 cm long, 0.5–1.2 cm wide, open, loosely-flowered with recemosely arranged branches; primary branches 2–4 mm long, excluding the awns, one per node, often purplish. Spikelet fasciles of three with one sessile or subsessile perfect spikelet and two short-pedicelled lateral spikelets staminate or sterile, the pedicels less than 0.2–0.5 mm long and the other two spikelets short-pedicelled, the pedicels about 0.7–1.2 mm long; glumes (1−)1.5–2.8 mm long, oblong and wider distally, 1-veined, apex deeply notched, awned, the awns 2–4 mm long, lobes triangular, acute; lemmas 2.5–3 mm long, fusiform, 3-awned, the central awns 5–13 mm long, lateral awns 2–3 mm long; paleas 2.5–3 mm long, puberulent, apex awned, the awns 1–2 mm long; anthers 1.6–1.8 mm long, yellowish to purplish. Caryopses 1−1.4 mm long, fusiform. 2n = 40, 60, 80.

Figure 5. 

A−D Muhlenbergia coerulea (Griseb.) Mez A habit B culm and panicle C ligule D spikelet E−K Muhlenbergia coerulea (Griseb.) Mez × Muhlenbergia rigida (Kunth) Kunth E culm and panicle F spikelet G floret H glumes I lemma J paleas, dorsal and ventral view K lodicules, stamens, and pistil. A−D drawn from P.M. Peterson, R.J. Soreng & J. Montoya Quino 21957 (US) E−K drawn from P.M. Peterson & N. Refulio Rodriguez 14860 (US).

Distribution

Muhlenbergia cenchroides ranges from throughout México, Central America to South America in Bolivia, Brazil, Colombia, Ecuador, Peru, Guyana and Venezuela.

Ecology

Muhlenbergia cenchroides occurs on rocky slopes, canyons, cliffs, roadcuts, arroyos, seeps and meadows associated Baccharis spp., Festuca myuros, Alnus, Polylepis, Fucaria, Salvia spp., Urochloa, Salvia spp., Calceolaria spp., Eupatorium, Festuca, Puya, Rubus, Schizachyrium, Cenchrus clandestinus, Calamagrostis spp., Muhlenbergia spp., Hyptis, Oxalis, Aristida, Begonia, Adiantum, Bidens, Lepechinia, Oreocallis grandiflora (Lam.) R. Br., Desmodium, Cortaderia bifida Pilg., Cortaderia jubata (Lemoine ex Carriere) Stapf, Sporobolus, Monnina, Carex, Cheilanthes, Eragrostis, Lupinus, Lycopodium, Jarava, Nassella, Werneria, Agave, Eucalyptus, Thalictrum and Chusquea; 1430–3850 m. Flowering December through September.

Comments

Muhlenbergia cenchroides can be separated from M. bryophilus in having anthers 1.6−1.8 mm long, the perennial habit with (10–) 25–55 cm tall culms and sessile or inconspicuously pedicelled perfect spikelets usually associated with two staminate or sterile pedicelled spikelets (Tovar 1993; Giraldo-Cañas and Peterson 2009).

Muhlenbergia cenchroides lies in a clade with M. tarahumara, M. uniseta and M. bryophilus in M. subg. Muhlenbergia (Fig. 1B; Peterson et al. 2010b). The multiple sampled individuals of M. cenchroides and M. uniseta in the current analyses do not resolve into reciprocally monophyletic lineages, but one sublineage, including accessions of each species, is strongly supported. This strongly suggests gene flow among individuals of these two species.

Specimens examined

Peru. Ancash: Prov. Bolognesi, Paramarca, cerros al E de Chiquián, 3680 m, 8 Apr 1952, E. Cerrate 1396 (MOL, USM); Prov. Carhuaz, Cordillera Negra, 22 km SW of Shupluy and Rio Santa, 9°17'19.7"S, 77°44'39.3"W, 3770 m, 13 Mar 2008, P.M. Peterson 21652, R.J. Soreng, M.I. La Torre & J.V. Rojas Fox (US, USM); Prov. Corongo, Cordillera Blanca, 3 km E of Yanac, 8°35'55.6"S, 77°50'4.8"W, 2849 m, 18 Mar 2008, P.M. Peterson & R.J. Soreng 21786 (US, USM); Prov. Corongo, Cordillera Blanca, E of Yungay, 3400 m, 5 Apr 1988, S.A. Renvoize & S. Lægaard 5055 (CPUN, K); Prov. Huaraz, W side of Cordillera Blanca, S of Quebrada Ishinca, 9°24'55.8"S, 77°32'45.8"W, 2885 m, 12 Mar 2008, P.M. Peterson 21614, R.J. Soreng, M.I. La Torre & J.V. Rojas Fox (US, USM); Prov. Huaraz−Recuay border, W side of Rio Santa Canyon, 19 km S of Huaraz, 9°40'58.1"S, 77°28'29.7"W, 3202 m, 11 Mar 2008, P.M. Peterson 21600, R.J. Soreng, M.I. La Torre & J.V. Rojas Fox (US, USM); Prov Huaylas, Cordillera Blanca, encima de Caraz, 3200 m, A Weberbauer 3234 (MOL); Prov. Huaylas, Huata, M.I. La Torre 2793 (USM); Prov. Pallasca, 17 km N of Huandoval and 6 km S of Pallasca, 3360 m, 27 Mar 1997, P.M. Peterson & N. Refulio Rodríguez 13927 (US, USM); 3.4 km N of Huandoval towards Huascaschuque, 8°18'59.5"S, 77°58'9.5"W, 2949 m, 21 Mar 2008, P.M. Peterson & R.J. Soreng 21817 (US, USM); Prov. Huari, near Laguna de Puruhay, M.I. La Torre 3692 (USM); San Marcos, A. Cano 13505 (USM); Huascarán National Park, Quebrada Rurichinchay, D. Smith 12659, A. Gonzales & D. Maldonado (USM); Prov. Recuay, Cordillera Blanca, 16 km E of Catac on road towards Chavin de Huantar, 3630 m, 21 Mar 1997, P.M. Peterson & N. Refulio Rodríguez 13833 (US, USM); Prov. Yungay, Cordillera Blanca, 20 km ENE of Yungay, 9°6'26.2"S, 77°41'8.2"W 3247 m, 15 Mar 2008, P.M. Peterson 21712, R.J. Soreng, M.I. La Torre & J.V. Rojas Fox (US, USM); Quebrada Llauganuco, 24 km ENE of Yungay, 9°5'46.3"S, 77°40'19.3"W, 3309 m, 16 Mar 2008, P.M. Peterson 21739, R.J. Soreng, M.I. La Torre & J.V. Rojas Fox (US, USM); Prov. Yungay, Huascarán National Park, Llanganuco sector, María Josefa trail between Chinancocha and Pucayacu, 77°39'W, 9°05'S, 3700−3850 m, 7 May 1985, D.N. Smith 10512 (CPUN, MO). Ayacucho: Ayna, L. Aucasime 258 (USM); Seqseqa, L. Aucasime 81 (USM); Prov. Huanca Sancos, 27 km NW of Putajasa and 3 km S of Sacsamarca, 13°57'51.1"S, 74°18'41.5"W, 3650 m, 25 Feb 2002, P.M. Peterson 16278, A. Cano, M. I. La Torre, A. Ramirez & D. Susanibar Cruz (US, USM). Cajamarca: near Cajamarca, 2700 m, 11 Mar 1986, B, Becker & F.M. Terrones H. 601 (LPB); Cajamarca to Celendín, 95 km from Cajamarca, above Quillimbas, 3000 m, 22 Mar 1988, S.A. Renvoize & S. Lægaard 4868 (CPUN, K); Prov. Cajamarca, 16 km W of Central Plaza of Cajamarca up road towards Cumbemayo on Avenida Peru, 3440 m, 31 Mar 1997, P.M. Peterson & N. Refulio Rodríguez 14012 (US, USM); Prov. Cajamarca, Dist. Baños del Inca, Tres Tingos, margen Oeste del río Chonta, 2900 m, 2 Mar 2002, I. Sánchez Vega 11261 (CPUN); Prov. Cajamarca, Cerro Huairapongo–Baños del Inca, 19 Nov 1965, I. Sánchez Vega 126 & Julio Mercado (CPUN); Prov. Cajamarca, Fundo Aylambo, a 5 km antes de la ciudad, 8 May 1969, I. Sánchez Vega 385 & W. Ruiz Vigo (CPUN); Prov. Cajamarca, cerca al Paso El Gavilán, 3100 m, 19 Apr 1975, I. Sánchez Vega 1407, P. Brandelard & J. Sanabria (CPUN); Prov. Cajamarca, Laguna de Moyococha, 2550 m, 29 Aug 1965, I. Sánchez Vega 92 (CPUN); Prov. Cajamarca, Dist. San Juan, lugar Huacraruco, 2350 m, 19 Jun 1993, J. Cabanillas S. & J. Guevara B. 615 (CPUN); Chotén, en el Arboretum de CICAFOR, a 4 km de la carretera Pacasmayo–Cajamarca, 2990 m, 23 May 1981, I. Sánchez Vega 2562, V. Torrel & E. Medina (CPUN); Prov. Cajamarca, Dist. Cajamarca. Paso El Gavilán, 3100 m, 26 Jun 1966, I. Sánchez Vega 239 (CPUN); Prov. Cajamarca, ladera que converge al Valle Cajamarca, Lla Colpa, 2900 m, 22 Apr 1975, I. Sánchez Vega 1416, P. Brandelard, J, Sanabria & W. Ruiz Vigo (CPUN); Prov. Cajamarca, Sais Atahualpa de Porcón, en el Arboretum de CICAFOR, 3400 m, 16 May 1981, I. Sánchez Vega 2512, V. Torrel P. & E. Medina (CPUN); Prov. Cajamarca, Dist. Namora, Hacienda Polloquito, 3000 m, 6 May 1967, I. Sánchez Vega 321 (CPUN);12 km N of Cajamarca on road towards Bambamarca, 3020 m, 14 Mar 2000, P.M. Peterson & N. Refulio Rodríguez 14855 (CPUN, US, USM); S of Paso El Gavelan, 10 air km S of Cajamarca, 7°15'37.2"S, 78°30'34.5"W, 2544 m, 26 Mar 2008, P.M. Peterson 21875, R.J. Soreng & I. Sánchez Vega (US, USM); cumbre El Gavilán, R. Ferreyra 3255 (USM); Prov. Celendin, 4 air km W of Celendin, 6°54'13.5"S, 78°10'8.4"W, 2687 m, 29 Mar 2008, P.M. Peterson 21925, R. J. Soreng & J. Montoya Quino (US, USM); Prov. San Ignacio, 31 km E of Sondor on road towards Tabaconas, 2490 m, 31 Mar 2000, P.M. Peterson & N. Refulio Rodríguez 15128 (CPUN, US, USM); Prov. San Miguel, Niepos, 2200 m, 30 Oct 1985, S. Llatas 1503 (CPUN); Prov. San Pablo, Dist. San Pablo, lugar El Molino, 2200 m, 12 Jun 1993, J. Sánchez Vega 663 (CPUN). Cusco: Prov. Calca, Manto a Amparaes, 2650 m, 18 Apr 1966, C. Vargas C. 17393 (LPB); Prov. Cusco, Socorro−K’inka, C. Vargas C. 13161 (USM); Ruinas de Sacsahuamán, 3500 m, 6 May 1983, S.G. Beck 8365 (LPB); Mandor, abajo de Machupicchu, 2000 m, 13 Apr 1957, H. Ellenberg 988 (LPB); Cusco−Huancaro hwy, P. Gutte & G. Muller 9425a (USM); Machupicchu, camino entre la ciudad inca de Machupicchu y el Puente del Inca, 2000 m, 18 Sep 2004, D. Giraldo-Cañas 3759 (COL). Huancavelica: Prov. Huancavelica, Huando, O. Tovar 1254 (USM). Huánuco: Prov. Huánuco, Carpish, cumbre entre Huánuco y Tingo María, 2700 m, 1 Oct 1950, R. Ferreyra 8070 (MOL); Prov. Huánuco, Carpish, cumbre entre Huánuco y Tingo María, R. Ferreyra 10022 (USM); 48.6 km NE of Huánuco towards Tingo María, T. Plowman & P.M. Rury s.n. (USM); Prov. Pachitea, 21 air km ENE of Huánuco, 9°51'53.1"S, 76°2'55.1"W, 2498 m, 6 Mar 2007, P.M. Peterson 20341, R.J. Soreng & K. Romaschenko (US, USM); Canyon of the Rio Grande, 44 air km E of Huánuco, P.M. Peterson 20363, R.J. Soreng & K. Romaschenko (US, USM). Junín: Prov. Huancayo, near Paián, O. Tovar 9311 (USM); Cerro al E de Huancayo, 3900 m, 2 May 1954, O. Tovar 2173 (US, USM); Prov. Tarma, entre Huancapistana, 2200 m, A. Weberbauer 2042 (MOL). La Libertad: Prov. Bolivar, entre el desvío a Uchumarca y Santa Luisa, 7°04'S, 77°49'W, 3700 m, 11 Nov 2001, I. Sánchez Vega 11194, M. Dillon & G. Iberico (CPUN); Prov. Bolivar, E side of Cerro Salumpuy, 8 air km NW of Bolivar, 7°7'39.2"S, 77°46'9.9"W, 3390 m, 30 Mar 2008, P.M. Peterson 21942, R. J. Soreng & J. Montoya Quino (US, USM); 3 air km ESE of Longotea on road to Bolivar, 7°3'27.9"S, 77°51'2.2"W, 3202 m, 31 Mar 2008, P.M. Peterson 21961, R. J. Soreng & J. Montoya Quino (US, USM). Lambayeque: Prov. Ferreñafe, Inkawasi, S. Llatas Quiroz 4122 (USM). Pasco: Prov. Oxapampa, Río Boqueria, 26 km from Oxapampa via Río Yamaquizu, D. Smith 1807, A. Pretel & L. Acosta (USM). Piura: Prov. Huancabamba, Porculla, 2200 m, 10 May 1992, S. Llatas Quiroz & H. De la Cruz S. 3098 (CPUN). San Martín: Prov. Mariscal Cáceres, puerto de Norte de Río Abiseo, A. Cano 7466, B. Young & J. Roque (USM).

Muhlenbergia ciliata (Kunth) Trin., Gram. Unifl. Sesquifl. 193. t.5, f.16. 1824.

Fig. 4D−G

Podosemum ciliatum Kunth, Nov. Gen. Sp. (quarto ed.) 1:128−129. 1816. Trichochloa ciliata (Kunth) Roem. & Schult., Syst. Veg. 2:386. 1817. Polypogon ciliatus (Kunth) Spreng., Syst. Veg. 1:243. 1825. Type: Mexico, Michoacán, Volcán de Jorullo, Sep, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P-HBK!; isotypes: BAA-1619 ex P!, BM!, P-Bonpl!, US-91918 fragm. ex P!).

Muhlenbergia adspersa Trin., Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 4(3–4):291. 1841. Type: Peru, Lima, ex herb. C.H. Mertens s.n. (holotype: LE?; isotypes: LE-TRIN-1486.01 fragm. ex LE herb. Mertens!, US-87236 fragm. ex LE herb. Mertens!).

Description

Sprawling, slender annuals. Culms 8–30 (−50) cm tall, glabrous, filiform, often tufted, freely branching at lower nodes; 0.2–0.5 mm diameter just below the inflorescence; internodes 6–42 mm long. Leaf sheaths (8−) 20–44 mm long, glabrous or sparsely pilose along the margins, shorter than the internodes; ligules 0.2–0.8 mm long, a ciliate membrane; apex truncate; margin with a tuft of hairs up to 1 mm long; blades 1–4 cm long, 0.6–1.4 mm wide, flat or loosely involute, often sparsely pilose above, glabrous below. Panicles 4–12 cm long, 1.8–5.0 cm wide, terminal, densely flowered; primary branches 1.5–3.7 cm long spreading and reflexed at maturity up to 90° from the rachises, one per node; pedicels 0.5–3 mm long, glabrous, appressed, erect; nodes 6–13 per panicle; Spikelets appressed to the branches, overlapping; glumes 0.7–1.7 mm long, subequal, glabrous, 1-nerved; apex acuminate, often mucronate; the mucro up to 0.5 mm long; lower glumes 0.7–1.5 mm long; upper glumes 0.8–1.7 mm long; lemmas 1.8–2.5 mm long, lanceolate, slender, awned, strongly 3-nerved but appearing five-nerved, the intermediate “nerves” actually rows of short barbs on top of folded epidermal ridges, sometimes with prominent short hairs (scabers) along the lateral nerves, often appearing glabrous without magnification, awns 5–11(−18) mm long, flexuous; callus minutely short pubescent; paleas 1.6–2.4 mm long, narrowly lanceolate, glabrous; anthers 0.3–0.5 mm long, yellowish. Caryopses 0.8–1.8 mm long, narrowly fusiform, brownish. 2n = 20.

Distribution

Muhlenbergia ciliata is found throughout México and Central America in Ecuador, Peru, Brazil, Bolivia, Brazil and Argentina.

Ecology

Muhlenbergia ciliata is found on moist to dry soils usually beneath taller vegetation, sandy drainages, steep rocky slopes, rock outcrops and disturbed roadsides in woodlands with Acacia, Agave, Andropogon, Bidens, Baccharis spp., Bothriochloa, Eupatorium, Melinus minutiflora P. Beauv., Muhlenbergia bryophilus, M. flexuosa, M. rigida, Puya and Salvia; 1000–2400 m.

Comments

Muhlenbergia ciliata is morphologically similar to M. romaschenkoi and can be differentiated from the latter in having short ligules 0.2−0.8 mm long [1.2−3.0 (−5.0) mm long in M. romaschenkoi], paleas that are glabrous between the veins on the proximal ½ (versus appressed pubescent), 6−13 nodes along the panicle (versus 15−23) and panicles that are 4−12 cm long (versus 7−15 cm long) [Peterson and Giraldo-Cañas 2011, 2012]. Some individuals of M. ciliata from Peru do not have prominent cilia along the lateral veins that are present in most individuals from North America.

Muhlenbergia ciliata is closely related to M. pectinata C.O. Goodd. (North America) and M. tenella (Kunth) Trin. (North America, Central America and Colombia) [Peterson and Annable 1991]. These three species form a clade in Muhlenbergia subg. Muhlenbergia (Peterson et al. 2010b; Fig. 1B).

Specimens examined

Peru. Amazonas: Piedra Grande, near Rio Santo Domingo, 5000 ft alt., 14−19 May 1923, J.F. Macbride 3684 (F, US). Cusco: Urubamba, Ruinas de Macchu Picchu, 2500 m, 27 May 1963, D. Ugent 5356 (US), 2300 m, 11 Apr 1963, C. Vargas C. 14354 (US), Mar 1987, I. Grignon 2306 (AAU, US); Quebrada Termas Macchu Picchu, 25 Mar 1966, C. Vargas C. 17145 (USM). Huánuco: 21 air km NE of Pachitea, 7 km E of Puerto Rancho junction, 9°49'45.9"S, 76°3'12.9"W, 2094 m, 6 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20336 (US); Pachitea, canyon of the Rio Grande, along trail 1 air km NW of Estación Huacachay, 9°50'44.7"S, 75°50'5.2"W, 2323 m, 8 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20378 (US); 2 air km ESE of Eastación Huacachay, 9°51'34.7"S, 75°50'48.1"W, 1867 m, 7 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20359 (US). Junín: between Tarma and La Merced, 3000 m, 14 Oct 1923, A.S. Hitchcock 22154 (US); Mito, 9000 ft alt., 8−18 Apr 1923, J.F. Macbride 3376 (F, US); Province Huancayo, abajo de Pariabuena, 2000 m, 6 May 1969, O. Tovar 7936 (USM). La Libertad: Bolivar, W of Longotea ca. 0.5 km towards San Vicente on Balsas−Longotea road, 7°2'35.6"S, 77°52'39.8"W, 2487 m, 31 Mar 2008, P.M. Peterson, R.J. Soreng & J. Montoya Quino 21967 (US).

Muhlenbergia coerulea (Griseb.) Mez, Repert. Spec. Nov. Regni Veg. 17:213. 1921.

Figs 5A−D, 6A−C

Epicampes coerulea Griseb., Abh. Königl. Ges. Wiss. Göttingen 19:256. 1874. Type: Sierra de Tucumán, Den grossen isolierten Buescheln an der Cuesta de Juntas, 23 Mar 1872, P.G. Lorentz 86 (lectotype, designated here: GOET-006633 [image!]; isolectotypes: CORD-00004624!, CORD-00004625!, US-865981!).

Crypsis phleoides Kunth, Nov. Gen. Sp. (quarto ed.) 1:140. 1816, non Muhlenbergia phleoides (Kunth) Columbus. Cinna phleoides (Kunth) Kunth, Révis. Gramin. 1:67. 1829. Epicampes phleoides (Kunth) Griseb., Abh. Königl. Ges. Wiss. Göttingen 19: 256. 1874. Type: Venezuela, Sucre, Sep, F.W.H.A. von Humboldt & A.J.A. Bonpland s.n. (holotype: P!; isotype: US-A865652 fragm. ex P!).

Crypsis stricta Kunth, Nov. Gen. Sp. (quarto ed.) 1:140. 1816, non Muhlenbergia stricta (J. Presl) Kunth. Cinna stricta (Kunth) Kunth, Révis. Gramin. 1:67. 1829. Crypsinna stricta (Kunth) E. Fourn., Mexic. Pl. 2:90. 1886. Type: Peru, Prov. de los Pastos, Dec, F.W.H.A. von Humboldt & A.J.A. Bonpland s.n. (holotype: B-W; isotype: US-A865653 fragm. ex B-W!).

Epicampes coerulea var. submutica Hack., Anales Mus. Nac. Buenos Aires 13:471. 1906. Type: Argentina, Tucumán, Dep. Tafí, Cuesta de Malamala, 2500 m, 4 Feb 1904, Stuckert herb. Arg. 14900 ex Lillo 3402 (holotype: W-1916-0026677 [image!]; isotypes: CORD-00001624 [image!], LIL-000053 [image!], US3168604!).

Description

Densely caespitose perennials. Culms 50−100(−120) cm tall, erect, rigid, hirsute below the basal, terete nodes; usually 1 node per culm; internodes mostly glabrous and scabrous. Leaf sheaths mostly 5−18 cm long, glabrous to scaberulous above, rounded near base, lower sheaths often becoming fibrous with age; ligules 8−15 mm long, firm below, strongly decurrent, often lacerate, apex obtuse to acute; blades 15−35(−45) cm long, 2−5 mm wide, tightly involute, glabrous to scaberulous below mostly scaberulous near above. Panicles (6−)10−24(−30) cm long, 6−15 mm wide, narrow, spike-like, usually plumbeous; primary branches 0.2−2.5 cm long, erect and tightly ascending appressed, floriferous to base; pedicels 0.5−4 mm long, usually shorter than the spikelets, hispid. Spikelets 5−7(−8) mm long, plumbeous, rarely 2-flowered; glumes (4−)5−7(−8) mm long, usually as long or longer than the floret, sometimes a little shorter, lanceolate, about equal, 1-nerved, scabrous, apex acuminate, unawned, mucronate, or short-awned; lemmas (4.6−)5−6.7(−7.1) mm long, lanceolate, plumbeous, scabrous, apex acuminate, unawned, mucronate or short-awned, the awn 1−3(−4) mm long, inserted just below the apex; callus sparsely short bearded, the hairs 0.1−0.2 mm long; paleas (4.6−)5−6.5 mm long, about as long as the lemma, narrowly lanceolate, scaberulous, apex acuminate; anthers 2−3 mm long, purplish or yellowish. Caryopses 2.5−3.5 mm long, fusiform, dark reddish-brown.

Figure 6. 

A−C Muhlenbergia coerulea (Griseb.) Mez A habit B panicle C spikelet D−F Muhlenbergia rigida (Kunth) Kunth D habit E panicle F spikelet. Drawings from Giraldo-Cañas and Peterson (2009), Peterson and Giraldo-Cañas (2011). A−C drawn from S.G. Beck 7700 (LPB) D drawn from P.M. Peterson 9659 (US) E, F drawn from P.M. Peterson, C.R. Annable & J. Valdés-Reyna 10876 (US).

Distribution

Muhlenbergia coerulea ranges throughout the Andean Cordillera from Colombia, Venezuela, Ecuador to Argentina, Peru and Bolivia.

Ecology

Muhlenbergia coerulea grows on rocky, often sandy slopes, derived from volcanic origins usually near arroyos associated with of Alnus, Anatherostipa obtusa (Nees & Meyen) Peñail., Aristida, Calamagrostis, Calceolaria, Festuca, Hypericum, Jarava ichu Ruiz & Pav., Lupinus, Monnina, Nassella, Oreocallis grandiflora (Lam.) R. Br., Polylepis, Puya, Rubus, Schizachyrium and cultivated Pinus; 2450−4900 m. Flowering February through August.

Comments

In recent literature (Giraldo-Cañas and Peterson 2009; Peterson and Giraldo-Cañas 2011, 2012), this species was referred to as Muhlenbergia angustata (J. Presl) Kunth but the type [Podosemum angustatum J. Presl] clearly aligns with what we had been referring to as the hybrid between this species and M. rigida. Therefore, we adopt the next available name, Muhlenbergia coerulea and change the hybrid designation to M. coerulea × M. rigida. Many specimens studied are intermediate between M. coerulea and M. rigida. These are treated as hybrids [M. coerulea (Griseb.) Mez × M. rigida (Kunth) Kunth; Lægaard and Peterson 2001; Peterson and Giraldo-Cañas 2011, 2012] since the size, width and colour of the panicles and the surface structure and length of the glumes and lemmas, are intermediate between these two recognised species.

Muhlenbergia coerulea is deeply embedded in the M. subg. Trichochloa clade, a group of tall, rather robust perennials historically placed in Podosemum or Epicampes (Soderstrom 1967; Peterson et al. 2010b; Fig. 1A).

Specimens examined

Peru. Ancash: Prov. Huaylas, Pueblo Libre, Antircán, A. Cano 11714 (USM); Prov. Huari, Huascarán National Park, Quebrada Pachachaca, D.N. Smith 12619, A. Gonzalez & D. Maldonado (USM); Quebrada Los Cedros, D.N. Smith 9892, R. Valencia & L. Minaya (CPUN); Prov. Huari, Huascarán National Park, Alpamayo−Cashampampa trail, 3950 m, 13 Mar 1985, D.N. Smith 10054 & R. Valencia (MO, USM); Prov. Recuay, between Pequipalpa and Rachacoco, L.I. Masías 44 (USM); Huascarán National Park, Auqispuquipio, D.N. Smith 12115, R. Valencia & M. Buddensiek (MO, USM); Prov. Yungay, Cordillera Blanca, 20 km ENE of Yungay, 9°6'26.2"S, 77°41'8.2"W, 3247 m, 15 Mar 2008, P.M. Peterson 21703, R.J. Soreng, M. La Torre & J.V. Rojas Fox (US, USM); quebrada Llauganuco, 24 km ENE of Yungay, 9°5'46.3"S, 77°40'19.3"W, 3309 m, 16 Mar 2008, P.M. Peterson 21720, R.J. Soreng, M. La Torre & J.V. Rojas Fox (US, USM). Arequipa: Prov. Caraveli, Quicacha, 5 May 1955, A. Guevara s.n. (USM). Ayacucho: Prov. Huanca Sancos, 19 km NW of Putajasa on road towards Huanca Sancos, 14°00'2.6"S, 74°17'14.1"W, 3900 m, 25 Feb 2002, P.M. Peterson 16268, A. Cano, M. La Torre, A Ramirez & D. Susanibar (US, USM). Cajamarca: Prov. Cajabamba, ca. 20 km WSW of Cajabamba, 7°42'18.0"S, 78°14'1.5"W, 3263 m, 23 Mar 2008, P.M. Peterson & R.J. Soreng 21868 (US, USM); Prov. Cajamarca, La Encañada, Cerro Negro, M. Cabanillas Medina & M. Sánchez Montoya 1530 (CPUN); La Encañada, ruta Combayo−Yanacocha, I. Sánchez Vega 10574 (CPUN); N del canal Cumbe Mayo, I Sánchez –Vega U. Molau 3733 (CPUN); Cumbe Mayo, W of Cajamarca, S.A. Renvoize 4990, S. Lægaard & I. Sánchez Vega (CPUN, K, US); Pampas de Guanico, ruta a Guagal, I. Sánchez Vega 1141 (CPUN); Sais Atahualpa, de Porcón, I Sánchez Vega 2528, V. Torrel & E. Medina (CPUN); Quebrada de la Esperanza along road to Cumbe Mayo, I. Sánchez Vega & V. Torre 3289 (CPUN); Cerro Campanario, I. Sánchez Vega 6605 (CPUN); Prov. Celendin, Celendin, 3600 m, 24 Jun 1961, R. Ferreyra 15117 (USM); Prov. San Miguel, 64 km N of Cajamarca and 3 km SW of El Cobro, 3530 m, 16 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14926 (CPUN, US, USM); Prov. San Pablo, 32 km NW of Cajamarca towards San Pablo, 3470 m, 15 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14882 (US, USM); Cajamarca−Chota road, km 37−40 marker, A. Gentry 61575, C. Diaz & C. Blaney (MO, USM). Huancavelica: Prov. Huancavelica, Canyon of Rio Ichu, SW of Huancavelica, 12°48'48.2"S, 75°3'24.5"W, 4894 m, 14 Mar 2007, P.M. Peterson 20462, R.J. Soreng, K. Romaschenko & D. Susanibar (US, USM); Tayacaja, Hacienda Tocas, between Colcabamba and Paucarbamba, 3400 m, 20 Apr 1954, O. Tovar 1981 (US, USM). Huánuco: Prov. de Huánuco, Mitotambo, above Mito, R. Ferreyra 6895 (MOL, US, USM); above Mitotambo, R. Ferreyra 9434 (USM); 3−6 mi NW of Mito, J.F. Macbride and Featherstone 1929 (F, US), Mito, J.F. Macbride and Featherstone 1721 (F, US); Prov. Ambo, Huarmiragra, A. Granda 1676 (USM). Junín: Pachacaya−Huari, 3600 m, 25 Mar 1979, O. Tovar 7838 (USM); Prov. Huancayo, Cerros E of Huancayo, O. Tovar 3259 (US); above Ocopilla, near Huancayo, O. Tovar 4506 (US, USM); above Huancayo, O. Tovar 2795 (US, USM); Palián, O. Tovar 9339 (USM); Cerros E of Huancayo, O. Tovar 3259 (USM); Oroya, A.S. Hitchcock 22182 (US). La Libertad: Prov. Huancayo, Acopalca, 4000 m, 20 Jul 1945, J. Infantes Vera 406 (LIL); Prov. Bolivar, 3 km ESE of Longotea and 9 km W of Uchumarca, 7°3'27.9"S, 77°51'2.2"W, 3202 m, 31 Mar 2008, P.M. Peterson 21957, R.J. Soreng & J. Montoya Quino (US, USM); Prov. Otuzco, Trujillo−Huamachuco road, 10−15 km before Shorey, D.N. Smith & R. Vasquez 3289 (MO, USM); Larbimbambu, 2450 m, 5 Feb 1949, J. Infantes Vera 1654 (LIL); Cerro Sango, A. Sagástegui 14428 (HAO); Prov. Santiago de Chuco, Shoreyo−Truillo road, 5 km from Shoreyo, D. Smith 2339 (MO, US, USM). Lambayeque: Prov. Ferreñafe, Incahuasi, S. Llatas Q. 1934 (CPUN, HAO, USM). Piura: Prov. Huancabamba, 14 km E of Sondor on road towards Tabaconas, 2540 m, 31 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 15153 (CPUN, US, USM). Puno: Chijnaya, Pueblo de Pucará, 3900 m, Mar 1964, A. Vera 107 (COL); Hacienda Caracara, entre Llave y Pucará, 3850 m, 4 Mar 1966, O. Tovar 5162 (US); Hacienda Sollocota, 3850 m, 7 Mar 1966, O. Tovar 5229 (USM); Camacani, 9 Mar 1966, 3850 m, O. Tovar 5263 (USM); Prov. Carabaya, 10 km S of Ollachea, J.D. Boeke & S. Boeke 2974 (NY, US); Prov. Chucuito, 3 km S of Pizacoma, 4050 m, 7 Mar 1999, P.M. Peterson & N. Refulio Rodriguez 14694 (US, USM).

Muhlenbergia coerulea (Griseb.) Mez × M. rigida (Kunth) Kunth.

Fig. 5E−K

Podosemum angustatum J. Presl, Reliq. Haenk. 1(4–5):229. 1830. Muhlenbergia angustata (J. Presl) Kunth, Enum. Pl. 1: 202. 1833. Type: Peru, Haenke s.n. (holotype: PR-4657!; isotype: PRC-450958 [image!]).

Muhlenbergia phragmitoides Griseb. var. breviaristata Hack., Annuaire Conserv. Jard. Bot. Genève 17: 291. 1914. Muhlenbergia breviaristata (Hack.) Parodi, Physis (Buenos Aires) 9: 219. 1928. Type: Argentina, Tucumán, Lara, 3200 m s.m., 28 Mar 1912, M. Lillo 11322, Herb. T. Stuckert 22470 (holotype: W-1916-0039607!; isotypes: LIL-40186!, US-3412353 fragm. ex W!).

Muhlenbergia holwayorum Hitchc., Contr. U.S. Natl. Herb. 24(8):389. 1927. Type: Bolivia, Sorata, 16 Apr 1920, E.W.D. Holway & M. M. Holway 530 (holotype: US-1108445!).

Description

Panicles (−0.6)1−4 cm wide, spike-like with lower branches slightly prolonged, erect, plumbeous to reddish-purple. Spikelets plumbeous to reddish-purple, scabrous; glumes 2.5−3.5(−4) mm long, ½ to ¾ as long as the floret; lemmas 4−6 mm long, awned, the awns generally 3−8(−10) mm long, straight.

Distribution

This presumed hybrid is known to occur in Argentina, Chile, Colombia, Ecuador, Peru and Venezuela.

Ecology

The hybrid occurs on gravelly slopes and near cultivated fields in many different plant communities between 2200−3800 m in association with Alnus, Aristida adscensionis L. Baccharis, Berberis, Calceolaria, Cenchrus clandestinus, Eragrostis pastoensis (Kunth) Trin., Festuca, Jarava, Lantana, Lupinus, Muhlenbergia cenchroides, M. phalaroides, M. rigida, Oxalis, Polygala, Puya, Schinus molle L., Schizochyrium and Solanum.

Comments

As expected, individuals of M. coerulea × M. rigida have an intermediate morphology, such as: lemma awn length [3−8 (−10) mm], glume length (1/2−3/4 as long as the lemma) and spikelet colouration (plumbeous to reddish-purple). In the Flora of Ecuador, Lægaard and Peterson (2001) recognised two intermediate forms (“intermediate” and “subangustata”) based on lemma awn length, glume length, colour of the spekelets and surface scabrosity of the glumes and lemmas.

There are no molecular studies investigating the population genetics of the hybrid with both presumed parents but we hope to persue this in the future. In our analysis, two samples of M. coerulea from Peru form a pair with little variation and two samples of M. rigida, one from Mexico and the other from Peru, form a pair with little variation in the analysis of seven DNA sequence markers (Peterson et al. 2010b). Each of these two clades of M. coerulea and M. rigida were not paired but were placed along a comb-like grade in the M. subg. Trichochloa clade. In our new analysis, there are more samples of M. rigida from Mexico and there is greater genetic variability among individuals of this species (Fig. 1). However, overall there appears to be low levels of divergence among species in M. subg. Trichochloa, hence the comb-like appearance suggesting rapid speciation (Peterson et al. 2010b).

Specimens examined

Peru. Ancash: 10 km towards Casma, S.A. Renvoize & S. Lægaard 5154 (CPUN); E of Yungay, S.A. Renvoize & S. Lægaard 5058 (CPUN); Prov. Asunción, Chacas, A. Cano 14572, M. La Torre & W. Mendoza (USM); Prov. Bolognesi, above Chiquián, E. Cerrate 1549 (US, USM); Prov. Corongo, Ocshmarca, S. Leiva 51 (USM); Prov. Huaylas, Huascarán National Park, Auquispuquio ruins, D.N. Smith 11960, R. Valencia & M. Buddensiek (CPUN, USM); Huascarán National Park, Pueblo Libre, A. Cano 11619 (USM); Pueblo Libre, Antircán, A. Cano 11714 (USM). Apurimac: Prov. Abancay, 48 km SW of Abamcay on road towards Andahuaylas, 13°42'23.6"S, 72°57'20.3"W, 3280 m, 21 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16650 (US, USM). Ayacucho: Prov. Huamanga, 23 km S of Ayacucho on hwy 3 towards Abancay, 13°16'21.5"S, 74°13'46.8"W, 3575 m, 15 Mar 2007, P.M. Peterson 20490, 20496, R.J. Soreng, K. Romaschenko & D. Susanibar Cruz (US, USM); 27 km S of Ayacucho on hwy 3 towards Abancay, 13°17'9.8"S, 74°13'41.9"W, 3684 m, 16 Mar 2007, P.M. Peterson 20502, R.J. Soreng, K. Romaschenko & D. Susanibar Cruz (US, USM); Prov. Huanca Sancos, 23 km NW of Putajasa on road towards Huanca Sancos, 13°58'11.1"S, 74°18'9.0W, 3800 m, 25 Feb 2002, P.M. Peterson 16272, A. Cano, M. La Torre, A Ramirez & D. Susanibar (US, USM); Prov. Huanca Sancos, 27 km NW of Putajasa and 3 km S of Sacsamarca, 13°57'51.1"S, 74°18'41.5"W, 3650 m, 25 Feb 2002, P.M. Peterson 16273B, A. Cano, M. La Torre, A Ramirez & D. Susanibar (US, USM); Prov. Lucanas, 13 km E of Puquio at km 172 marker, 14°41'18.5S, 74°4'26.8W, 3730 m, 8 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18207 (US, USM); Ancamarca, L. Vargas & G. Mora 337 (USM). Cajamarca: Prov. Cajamarca, 12 km N of Cajamarca on road toward Bambamarca, 3020 m, 14 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14860 (CPUN, US, USM); Cajamarca−Bambamarca, 13−18 km from Cajamarca, D.N. Smith & R. Vasquez M. 3441 (MO, US, USM); Chotén, 4 km de la carretera Pacasmayo, I. Sánchez Vega 2570, V. Torrel & E. Medina (CPUN); Porcón, I. Sánchez Vega 51 (CPUN, US); above La Encañada ruta a Celendín, I. Sánchez Vega & W. Ruiz Vigo 1730 (CPUN); Prov. Celendín, La Tranca, I. Sánchez Vega & W. Ruiz Vigo 1815 (CPUN); Prov. Celendín, 4 air km W of Celendín, 6°54'13.5"S, 78°10'8.4"W, 2687 m, 29 Mar 2008, P.M. Peterson 21921 & 21922, R.J. Soreng & J. Montoya Quino (US, USM); 10 km from Celendín towards Rio Marañon, S.A. Renvoize & S. Lægaard 4883 (CPUN); Celendín to Cajamarca, near Quillimbas, S.A. Renvoize & S. Lægaard 4871 (CPUN); Cerro Conturami 10 km from Celendín, S.A. Renvoize & S. Lægaard 4946 (CPUN); Prov. Contumaza, Tres Cruces, A. Sagástegui & M. Fukushima 5119 (US); Celendín−Balsas road, 3−10 km from Celendín, D.N. Smith & I. Sánchez Vega 4300 (MO, US). Cusco: Prov. Calca, 10 km N of Calca on road towards Lares, 13°16'2.9"S, 71°55'20.1W, 3490 m, 17 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16597 (US, USM); Prov. Santo Tomas, Chumbivilcas, Apr 1982, M.E. Tapia 208 (USM). Huancavelica: Motcca, cerca a Conaica, 3500 m, 1 Apr, 1967, O. Tovar 5889 (USM); Prov. Huancavelica, Pararpuquio, below Conaica, O. Tovar 169 (MOL, US, USM); Sachahuajta, 7 km to Conaica, O. Tovar 950 (US, USM); near Yauli, O. Tovar 2996 (US, USM); Yacu−huanay, O. Tovar 3695 (USM, US); Prov. Tayacaja, Andaimarca, between Colcabamba and Surcubamba, O. Tovar 1821 (US, USM). Huánuco: Prov. de Huánuco, Mitotambo above Mito, R. Ferreyra 9477 (US, USM); Mito, J.F. Macbride 3320 (F, US). Junín: Prov. Huancayo, Paccba, 20 km S of Huancayo, O. Tovar 3294 (US, USM); Cerro La Libertad, O. Verlarde Nuñez 2637 (MOL). La Libertad: Prov. Bolivar, above Longotea, ruta Bolivar, I. Sánchez Vega 5015 (CPUN); Prov. Otuzco, Agallpampa, A. López M. 1041 (US); Trujillo−Huamachuco road, D.N. Smith & R. Vasquez 3309 (MO, USM). Lambayeque: Prov. Ferreñafe, Inkawasi, S. Llatas Quiroz 4114 (USM). Lima: Prov. Canta, 2 km SE of San Jose Canta, 11°30'2.0"S, 76°40'23.4W, 2232 m, 27 Mar 2004, P.M. Peterson & N. Refulio Rodriguez 17984 (US, USM). Piura: 14 km E of Sondor on road towards Tabaconas, 2540 m, 31 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 15160 (CPUN, US, USM).

Muhlenbergia diversiglumis Trin., Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 6,4(3–4):298. 1841.

Fig. 7A−D

Type

Mexico, Porto Pedro, Karwinsky 1393 (holotype: LE-TRIN-1497.01!; isotypes: US-84831! fragm. ex LE-TRIN-1497.02, W!).

Description

Sprawling annuals. Culms 16–50 cm tall, decumbent, rooting at the lower nodes; nodes retrorsely pilose; internodes smooth or scabridulous. Leaf sheaths 1.5–8.5 cm long, sparsely or densely pilose, hairs to 3 mm long, papillose-based; ligules 0.5–0.8 mm long, membranous, apex truncate, erose; blades 2–6 cm long, 1.5–4 mm wide, flat, bases distinctly narrowed to the junction with the sheath, surfaces scabridulous and sparsely pilose, hairs papillose-based. Panicles 6–10.5 cm long, 2.0–4.5 cm wide, secund, open; primary branches 0.8–3.5 cm long, secund, spreading at right angles or somewhat reflexed usually lying to one side with 2–5 spikelets; secondary branches not developed; pedicels 1–5 mm long, scabrous or shortly pilose, hairs papillose-based; disarticulation at the base of the primary branches where there is a weak and contorted stipe. Spikelets 4–8 mm long, dimorphic with respect to the glumes, proximal spikelets on each branch almost sessile; glumes of proximal spikelets on each branch subequal, 0.2–0.7 mm long, orbicular, truncate, often erose or irregularly toothed, unawned; glumes of distal spikelets on each branch markedly unequal; lower glumes to 8 mm long, 1-veined, acute, usually awned, awns 0.5–3 mm; upper glumes orbicular, acute, sometimes awn-tipped; lemmas 4.0–7.6 mm long, linear to broadly lanceolate, light greenish, smooth or scabrous, usually with greenish veins, apices acuminate, awned, awns 6–19 mm long, usually straight, scabrous; paleas 3.7–6.8 mm long, narrowly lanceolate, coarsely papillate or almost smooth, 2-keeled, the veins prominent, scabrous, greenish, sometimes extending as minute awns, acuminate; anthers 0.4–0.8 mm long, yellowish. Caryopses 1.8–3 mm long, oblong-ovoid, flattened, brownish. 2n = 20.

Figure 7. 

A−D Muhlenbergia diversiglumis Trin A habit B ligule C glumes D floret E−H Muhlenbergia microsperma (DC.) Kunth E habit F ligule G glumes H lemma. Drawings from Peterson and Annable (1991) A−D drawn from P.M. Peterson & C.R. Annable 4158 (WS) F−H drawn from P.M. Peterson & C.R. Annable 4185 (WS).

Distribution

The species is native to North America, Central America, Colombia, Venezuela, Ecuador, Peru, and Argentina.

Ecology

Muhlenbergia diversiglumis grows on moist cliffs, along water courses, sandy slopes, and road cuts, primarily in moist shaded environments of broadleaf evergreen forests and pine-oak forests, at elevations of 600–2500 m.

Comments

Muhlenbergia diversiglumis can be differentiated from M. ciliata, M. microsperma, and M. romaschenkoi in having secund panicles (versus not secund in the latter three species) with each primary branch consisting of 2–5 dimorphic spikelets where the proximal spikelets have short orbicular glumes less than 1 mm long, and the distal spikelets have glumes up to 8 mm long (Peterson and Annable 1991; Giraldo-Cañas and Peterson 2009).

Muhlenbergia diversiglumis is a member of M. subg. Muhlenbergia and is sister to M. alamosae Vasey and together they are sister to the M. tarahumaraM. cenchroidesM. bryophilusM. uniseta clade (Fig. 1B).

Specimens examined

Peru. Amazonas: Dist. Vista Alegre, Puente sobre el Río Salas, 1525 m, 30 Jun 1998, I.M. Sánchez Vega, M.O. Dillon & M. Zapata 9580 (HAO, MO). Ayacucho: Naranjayoc, entre Ayna y el Río Apurimac, 900 m, 16 May 1969, O. Tovar 6136 (USM); Ayna, cerca entre Tambo y San Francisco, Jan 1969, L. Aucasime 428 (USM); Province La Mar, Machente, entre Yanamonte y Ayna, 1200 m, 16 May 1969, O. Tovar 6126 (USM); Province La Mar, entre Ayna & Río Apurimac, 900 m, 16 May 1969, O. Tovar 6136 (USM); Ayna, between Huanta and Río Apurimac, 750 m, 7 May 1929, E.P. Killip & A.C. Smith 23127 (US). Cusco: Urubamba Valley, San Miguel, 1800 m, 28 May 1913, O.F. Cook & G.B. Gilbert 958 (US); Urubamba, Ciudadela Macchu Picchu, 2300 m, 11 Apr 1963, C. Vargas C. 2159 (US), 14355 (US, USM); Urubamba, Macchu Picchu, 2040 m, Mar 1949, F. Marin 1381 (US); Urubamba, 110 km de Cusco en el camino y atrás de las aguas termales con plantaciones de palta, Macchu Picchu, 2050 m, 21 May 1988; G. Valencia & R. Ochoa 9147 (MO, US). Huánuco: Province Leoncio Prado, La Divisoria, carretera a Pucallpa, 1600 m, 21 Apr 1989, J. Schunke Vigo 11349 (MO, US, USM). Piura: Huancabamba, Porculla, 1770 m, 6 Mar 1989, S. Llatas Quiroz 2431 (CPUN, HAO, MO).

Muhlenbergia fastigiata (J. Presl) Henrard, Meded. Rijks-Herb. 40: 59. 1921.

Fig. 8A−E

Sporobolus fastigiatus J. Presl, Reliq. Haenk. 1 (4–5): 241. 1830. Type: Peru, Haenke s.n. (holotype: PR, isotypes: PRC-450197 [image!], US-3048470! fragm. ex PR).

Muhlenbergia cleefii Lægaard, Caldasia 17 (82–85): 409–411. 1995. Type: Colombia, Boyacá, Sierra Nevada del Cocuy, Alto Valle de Lagunilla, páramo pantanoso al sur de la Laguna Cuadrada, 4060 m, 26 sep 1972, A. Cleef & P.A. Florschutz 5578 (holotype: COL!; isotypes: U-0007997 [image!], US-2785756!).

Description

Dense mat-forming perennials with scaly rhizomes, the acute scales 4.5−8.1 (−10) mm long, the rhizomes 1−2 (−2.5) mm in diameter. Culms 2−8 (−11) cm long, mostly erect, 2−3 (4) mm diameter below; internodes 1−10 mm long, compressed. Leaf sheaths 3−6 (−10) mm long, distichous, overlapping, margins hyaline; ligules 6−1.4 mm long, membranous, decurrent, apex acute to obtuse; blades 2.5−8.5 mm long, 0.6−1.1 mm wide, involute, arcuate, glabrous to finely papillose, margins scabrous, apex navicular, often pungent. Panicles 1−2 cm long, 1−5 mm wide, contracted, narrow, usually exserted with 3−9 nodes; primary branches 0.4−1 cm long, ascending, solitary at a node; rachis papillose-roughened just below the spikelets. Spikelets (1.8−-) 2−2.5 mm long, plumbeous; glumes (0.8−) 1−1.6 mm long,about ½ as long as the floret, subequal, 1-veined, rarely 2-veined, apex acute to obtuse; lemmas (1.7−) 1.9−2.4 mm long, 3-veined, glabrous, plumbeous, apex acute, mucronate, the mucros less than 0.3 mm long; paleas (1.6−) 1.8−2.4 mm long, 2-veined, glabrous; anthers 1−1.7 mm long, yellow or purple. Caryopses 1−1.3 mm long, about 0.4 mm wide, ellipsoid, dark brown.

Figure 8. 

A−E Muhlenbergia fastigiata (J.Presl) Henrard A habit B ligule C glumes D floret E stamens and pistil F−J Muhlenbergia ligularais (Hack.) Hitchc F habit G ligule H glumes I floret J stamens and pistil. Drawings from Giraldo-Cañas and Peterson (2009), Peterson and Giraldo-Cañas (2011) A−E drawn from P.M. Peterson, S. Lægaard, R.J. Soreng & C.R. Annable 12709 (US) F−J drawn from P.M. Peterson, S. Lægaard, R.J. Soreng & C.R. Annable 12684 (US).

Distribution

Muhlenbergia fastigiata is found in South America in the Andean highlands of Argentina, Bolivia, Chile, Colombia, and Peru (Morden 1985; Morden and Hatch 1996).

Ecology

Muhlenbergia fastigiata occurs on grassy flats, playas, slopes, rock outcrops, near gravelly creeks and lake margins in granitic and calcareous soils associated with Baccharis, Berberis, Calamagrostis, Ephedra, Festuca, Jarava, Margyricarpus, Muhlenbergia, ligularis, M. peruviana, and Nassella; 3000−4900 m.

Comments

Morphologically, M. fastigiata can sometimes be confused with the distantly related M. ligularis (M. subg. Bealia; Fig. 1B). However, the former has well developed rhizomes (absent in M. ligularis) and tightly involute, acuate leaf blades (versus flat and straight). Muhlenbergia richardsonis (Trin.) Rydb., a wide ranging North American species, is also morphologically similar to M. fastigiata in most characters, although M. richardsonis has a taller habit and differes in leaf anatomy (Morden 1985; Morden and Hatch 1996). Aciachne acicularis Lægaard and A. pulvinata Benth., two small, compact, mat-forming perennials, can also be mistaken for M. fastigiata. However, both species of Aciachne (Pooideae: Stipeae) have longer spikelets ranging from 3.8−6 mm long, glumes that are 3−5-veined, and tightly overlapping lemma margins (Renvoize 1998; Giraldo-Cañas and Peterson 2009).

Muhlenbergia fastigiata is sister to the North American, M. richardsonis in M. subg. Pseudosporobolus [Fig. 1; Peterson et al. 2010b].

Specimens examined

Peru. Ancash: Recuay, Cordillera Blanca, 39 km S of Catac on road towards Raquia, 3980 m, 21 Mar 1997, P.M. Peterson 13825 & N. Refulio Rodriguez (US, USM); Cordillera Negra, E slope of Cerro Pullicharca (Purac), ca. 1.5 km W of hwy 109 and then 3.6 km S of Tapacocha along Rio Santa, 9°55'39.4"S, 77°23'45.3"W, 3822 m, 9 Mar 2008, P.M. Peterson 21512, R.J. Soreng, M.I. La Torre & J.V. Rojas Fox (US, USM); between Santa Rosa and Araranca 12 Apr 1915, O.F. Cook & G.B. Gilbert 168 (US). Arequipa: Prov. Caylloma, Valle de Colca, Chiray−Tuti, 3900 m, 12 Jan 1999, S.G. Beck 26354 (LPB); Prov. Caylloma, Pampa Cañahuas, “Grama dulce”, 4200 m, 3 Jul 2001, M. Rodríguez Diaz 1130 (USM). Cajamarca: Prov. Hualgayoc, 8 km NE of Hualgayoc on hwy 3N towards Bambamarca, 3080 m, 17 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14950 (CPUN, US, USM). Kanzel, above Sunchubamba, 3680 m, 6 Aug 1957, H. Ellenberg 1852 (US). Cusco: Chumbivilias, Rio de Velille, 3850 m, C. Vargas C. 14084 (US); Espinar, alrededores de Yauri, 3900 m, 26 Mar 1956, 26 Mar 1956, C. Vargas C. 11209 (US). Huancavelica: Huancavelica, Canyon of Rio Ichu, SW of Huancavelica ca. 5 km on Hwy 3 to Santa Ines and Ayacucho, 12°48'48.2"S, 75°3'24.5"W, 4894 m, 14 Mar 2007, P.M. Peterson 20463, R.J. Soreng, K. Romaschenko & D. Susanibar Cruz (US, USM); Tayacaja, Just above Chuquitambo, 4 km SW of Pazo, 3975 m, 9 Apr 1997, P.M. Peterson 14151 & O. Tovar (US, USM). Junín: Prov. Huancayo, Acopalca, 3900 m, 25 Jul 1945, J. Infantes Vera s.n. (LIL); Prov. Huancayo, Acopalca, 4000 m, 20 July 1947, J. Infantes Vera 446 (LIL); entre Tarma y La Oroya, 3700 m, A. Weberbauer 2525 (MOL); Hacienda Cachi-Cachi, 4000 m, 22 Oct 1950, O. Velarde Nuñez 2869 (MOL); Jauja, 34 km SE of La Oroya on road towards Jauja, 3600 m, 9 Apr 1997, P.M. Peterson 14125 & O. Tovar (US, USM); Jauja, Tarma−Jauja road, 28 km from Tarma, 11°35'S, 75°38'W, 3950 m, 10 Jan 1984, D.N. Smith 5694 (MO, US); Junín, SE shore of Lago Chinchay Cocha (Junin) and 8 km S of Huayre, 4110 m, 7 Apr 1997, P.M. Peterson 14096 & O. Tovar (US, USM); Yauli, 156 km W of Lima just above Yauli, 4120 m, 5 Apr 1997, P.M. Peterson 14040 & O. Tovar (US, USM); Yauli, La Oroya, 30 Nov 1924, F.L. Stevens 1 (US); Oroyo, 23 Oct 1923, A.S. Hitchcock 22135 (US), 21 Feb 1954, Hirsch s,n. (US), Stevens 1 (US); entre Tarma y Oroya, 3400 m, 29 Jun 1948, R. Ferreyra 3828 (MOL, US, USM); ca. 24 km W of Tarma, 4050 m, 6 May 1979, Teppner 79/387 (US). La Libertad: Prov. Huamachuco, Cangau Sartimbamba, 3200 m, 28 Jan 1952, J. Infantes Vera 4072 (LIL); Prov. Huamachuco, Cangau Sartimbamba, 4000 m, 29 Jan 1952, J. Infantes Vera 4045 (LIL); Prov. Huamachuco, Huailillas, 3800 m, 8 Aug 1951, J. Infantes Vera s.n. (LIL). Lima: Provincia Huarochiri, Chilca, Bella Vista, 3800 m, 5 Jun 1940, E. Asplund 11436 (NY, US); road from Lima to Huancayo, 3300 m, 20 May 1981, G. Sullivan, K. Young, S. Sánchez & D. Soejarto 1021 (MO, US). Pasco: Pasco, 8 km W of NW arm of Laguna de Junín, 10°55'51.9"S, 76°18'8.6"W, 4141 m, 5 Mar 2007, P.M. Peterson 20313, R.J. Soreng & K. Romashchenko (US, USM). Puno: Chucuito, 3 km NE of Zepita on road towards Copani, 3820 m, 5 Mar 1999, P.M. Peterson 14631, N. Refulio Rodriguez & F. Salvador Perez (US, USM); 20 km E of Huacullani on road towards Desaguadero, 3880 m, 5 Mar 1999, P.M. Peterson 14645, N. Refulio Rodriguez & F. Salvador Perez (US, USM); 5 km S of Kelluyo, 3860 m, 7 Mar 1999, P.M. Peterson 14686, N. Refulio Rodriguez & F. Salvador Perez (US, USM); El Collao, 11 km E of Santa Rosa and 5 km W of Mazo Cruz, 3880 m, 2 Mar 1999, P.M. Peterson 14598, N. Refulio Rodriguez & F. Salvador Perez (US, USM); 9 km N of Conduriri and 63 km S of Ilave along the Rio Huenque, 3820 m, 3 Mar 1999, P.M. Peterson 14600, N. Refulio Rodriguez & F. Salvador Perez (US, USM); Provincia Melgar, 7 km WNW of Santa. Rosa, 14°35'54.9"S, 70°51'34.7"W, 4002 m, 23 Mar 2007, P.M. Peterson 20605, R.J. Soreng & K. Romashchenko (US, USM); SW of Juliaca ca. 8 km on Hwy 30 to Arequipa, 15°32'37.2"S, 70°12'55.9"W, 3854 m, 31 Mar 2007, P.M. Peterson 20715, R.J. Soreng, K. Romaschenko & S. Gonzalez Elizondo (US, USM); Puno, 2 km N of Laraquerion road towards Puno, 16°6'59.1"S, 70°1'59.1"W, 3940 m, 18 Apr 2004, P.M. Peterson 18327 & N. Refulio Rodriguez (US, USM); San Roman, 4 km E of Santa Lucia, 15°41'4.2"S, 70°34'8.0"W, 4030 m, 19 Apr 2004, P.M. Peterson 18332 & N. Refulio Rodriguez (US, USM); 21 km W of Santa Lucia and 5 km E of Puente Cañuma (Laguna Lagunillas), 15°40'4.1"S, 70°47'4.4"W, 4260 m, 20 Apr 2004, P.M. Peterson 18344 & N. Refulio Rodriguez (US, USM); Camjata Hacienda, Capachica Peninsula, Lake Titicaca, Tutin 975 (NY); between Juliaca and Cusco, 3880 m, 27 Nov 1923, A.S. Hitchcock 22448 (US); Hacienda Pairumani, 20 mi SW of Llave, 3900 m, 21 Jul 1946, O.P. Pearson & A. Pearson 14 (US); between Puno and Laguna Umayo, N of Puno, 3970 m, 12 Sep 1959, H.G. Barclay 9265 (US). Tacna: Cordillera Volcan Tacora, Ancara, Werderman 1138 (NY, US); Tarata, 11 km NW of Yabroco on road towards Cano, 3680 m, 16 Mar 1999, P.M. Peterson 14814, N. Refulio Rodriguez & F. Salvador Perez (US, USM).

Muhlenbergia flexuosa Hitchc., Contr. U.S. Natl. Herb. 24(8): 388. 1927.

Fig. 9A−E

Type

Peru, Huacachi Estacion near Muna, summit of rocky crest, 2000 m, 20 May−1 Jun 1923, J.F. Macbride 3874 (holotype: F-534937!; isotypes: BAA-1622!, BM-000938657 [image!], G-00099373 [image!], K!, LE!, US-1256339!).

Description

Caespitose perennials. Culms 15−40 cm tall, slender, 0.3−0.4 mm diameter just below the panicle with 6−8 nodes per culm; internodes 1−6 cm long near base, glabrous, shiny. Leaf sheaths about as long as the internodes below, glabrous; ligules 0.3−0.5 mm long, membranous, apex truncate, lacerate; blades 2−5 cm long, 1−2.2 mm wide, flat, scaberulous, apex acuminate. Panicles 3.5−6.5 (−7) cm long, 0.5−1.5 cm wide, narrow, spiciform, sometimes interrupted below; primary branches 0.5−2.5 cm long, tightly apressed to loosely ascending or spreading, not more than 45° from the culm axis. Spikelets 2.8−4.2 mm long, yellowish to light brown, erect or drooping; glumes 2.8−4 mm long, including mucos or awns, subequal, hyaline to membranous, glabrous, 1-veined, scabrous along the midvein, apex acute, unawned, mucronate or awned, the awns up to 1.3 mm long, straight or loosely flexuous; lemmas 2.8−4.2 mm long, hyaline to membranous, 3-veined, scaberulous, lower 1/3 sparsely hairy, apically awned, the awns 14−30 mm long, flexuous, callus hairy, the hairs up to 0.4 mm long; paleas about as long as the lemmas, 2-veined, glabrous, apex acuminate, often mucronate; anthers 1.3−1.6 mm long, purple. Caryopses 1.4−1.6 mm long fusiform, light brown.

Figure 9. 

A−E Muhlenbergia flexuosa Hitchc. A habit B ligule C glumes D floret E stamens and pistil. Drawn from H. Teppner 79-293 (US).

Distribution

Muhlenbergia flexuosa endemic to Peru and is known from only a few collections from Huánuco, Pasco and San Martín departments (Hitchcock 1927; Tovar 1993).

Ecology

Steep talus slopes, rocky trail cuts and rock outcropts with Andropogon, Acacia, Chusquea, Baccharis, Puya, Salvia, Rubus, Muhlenbergia ciliata, M. beyrichiana, Acanthaceae and Melastomataceae; 1200−2530 m.

Comments

Hitchcock (1927) suggested Muhlenbergia flexuosa was allied with M. flaviseta Scribn. and M. watsoniana Hitchc. (≡ M. scabra S. Watson), since all have short flat blades, spike-like panicles and slender flexuous awns. However, Muhlenbergia flaviseta and M. watsoniana are members of the M. subg. Clomena clade while M. flexuosa is sister to M. plumiseta Columbus−M. pereilema P.M. Peterson−M. beyrichiana clade, all of which are included in M. subg. Muhlenbergia (Fig. 1; Peterson et al. 2010b). Within Muhlenbergia, the derivation of a slender flexuous awn found in M. flexuosa has occurred in four of the five subgenera currently recognised within the genus and is only lacking in M. subg. Pseudosporobolus (Fig. 1B; Peterson et al. 2010b).

Specimens examined

Peru. Huánuco: Rio Huallaga Cañon, below Rio Santo Domingo, 1316 m, 3 Jun 1923, J.F. Macbride 4205 (US); Pachitea, Canyon of the Rio Grande, 44 air km E of Huánuco, 2 air km ESE of Estación Huacachay (Huacachi), 9°51'34.7"S, 75°50'48.1"W, 1867 m, 7 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20358 (MO, US, USM); 1.5 air km SE of Estación Huacachay (Huacachi), 9°51'42.8"S, 75°50'23.4"W, 2383 m, 8 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20365 (MO, US, USM); along trail 1/3 air km NW of Estación Huacachay (Huacachi), 9°51'1.4"S, 75°49'53.4"W, 2519 m, 8 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20373 (US, USM). Junin: Cerro Taldes, Rio Huancabamba, 31 km S of Pozuzo and 3 km N of Llullitunqui, 1370 m, 1 Jun 1979, H. Teppner 79-293 (US). Pasco: Oxapampa, Pozuzo, 21 Jul 1978, Ellemberg 8934 (USM). San Martín: Mariscal Caceres, 2350 m, 13 Aug 1986, K. Young 4234 (MO).

Muhlenbergia ligularis (Hack.) Hitchc., Contr. U.S. Natl. Herb. 24(8):388. 1927.

Fig. 8F−J

Sporobolus ligularis Hack., Oesterr. Bot. Z. 52(2):57. 1902. Type: Ecuador, Pichincha, 23 Jan 1899, Sodiro s.n. (holotype: W; isotypes: BAA-2905! ex W, US-3274313! ex W, US-1163183!).

Muhlenbergia calcicola Swallen, Contr. U.S. Natl. Herb. 29(9):407. 1950. Type: Guatemala, Huehuetenango, Chemal, Sierra de los Chuchumatanes, 3300 m, 31 Dec 1940, P.C. Standley 81703 (holotype: US-1910686!; isotypes: F-1200274 [image!], US-2236500US!).

Muhlenbergia breviculmis Swallen, Contr. U.S. Natl. Herb. 29(9):408. 1950. Type: Guatemala, Huehuetenango, Cerro Chemalito, Sierra de los Cuchumatanes, 3.5 mi W of Santa Eulalia, 3100−3150 m, 2 Aug 1942, J.A. Steyermark 49905 (holotype: US-1935054!; isotypes: F, US-2208654!).

Muhlenbergia minuscula H. Scholz, Willdenowia 14:393. 1984. Type: Bolivia, Canton Ulla-Ulla, Pampa von Ulla-Ulla, Apolobamba Cordillera, 4450 m, 26 Feb 1983, Menhofer 1974 (holotype: B!; isotype: LPB-0000293 [image!]).

Description

Loosely tufted annuals to short-lived perennials. Culms 2−12 cm tall, 0.2−0.4 mm diameter just below the panicle, erect or decumbent, slender, glabrous, sometimes flowering the first year, up to 15 cm broad, dying in the centre, profusely branched below, a short branchlet with fascicled leaves borne at each node, with 4−6 nodes; internodes 2−20 mm long. Leaf sheaths 2−20 mm long, generally shorter than the internodes, glabrous, ridged, flattened by the densely fascicled branches; ligules 0.6−2.5 mm long, membranous to hyaline, apex truncate to rounded; blades 0.3−2.2 cm long, 0.8−1.5 mm wide, flat or folded, prominently veined, thick, firm, usually with whitish-thickened midvein and margins, conspicuously crystalline or spiculate on both surfaces, otherwise glabrous below, sparsely scaberulous above and along margins, tapering to a boat shaped tip. Panicles 1.0−3.0 cm long, 0.3−1.4 cm wide, long exserted or included in the uppermost sheath, loosely contracted; branches 5−9 mm long, one per node, appressed or reflexed at maturity up to 70° from the culm axis; pedicels 1−3 mm long, stiff, densely scabrous, spiculate, erect. Spikelets 1.5−3.0 mm long, often plumbeous to reddish-purple; glumes 1.0−1.9 mm long, subequal, glabrous, apex acute to obtuse, often minutely erose, greenish-grey; lower glumes 1.0−1.7 mm long, 1-veined; upper glumes 1.1−1.9 mm long, 1-veined or occasionally 3-veined; lemmas 1.5−3.0 mm long, lanceolate, 3-veined, keeled, glabrous, mottled with greenish-black areas or dark greenish mottles on a pale background, apex minutely scaberulous, acuminate, entire or mucronate; mucro rarely more than 1 (−1.2) mm long; paleas 1.4−2.9 mm long, lanceolate, glabrous; anthers 0.8−1.1 mm long, purplish becoming pale. Caryopses 0.8−1.2 mm long, elliptic to fusiform, brownish.

Distribution

This species ranges from Guatemala and Costa Rica (Pohl 1980, at Chirripo Grande) to Colombia, Venezuela, Ecuador, Bolivia, Peru and Argentina.

Ecology

Muhlenbergia ligularis occurs in grassy flats, moist depressions, wet meadows, gravelly banks, ridgetops and gravelly roadsides often derived from calcarious subtrates associated with Achnatherum, Aciachne, Agrostis, Alnus, Anatherostipa, Baccharis, Berberis, Bidens, Buddleya, Caiophora, Calamagrostis, Carex, Colletia spinosissima J.F. Gmel., Eleocharis, Festuca, Gaultheria, Hypericum, Jarava, Juncus, Lepidophyllum, Lupinus, Margyricarpus, Muhlenbergia spp., Nassella, Cenchrus clandestinus, Plantago, Poa, Puya, Rumex, Salvia and Senecio; 2320−4650 m. Flowering September through January in Central America and February to July in Peru or when moisture is available.

Comments

Muhlenbergia ligularis is morphologically similar to M. fastigiata and can be separated from the latter by possessing flat leaf blades, 0.8−1.5 mm wide and a rather loosely tufted habit without wiry creeping rootstocks and scaly rhizomes. Morphologically, M. ligularis differs from M. caxamarcensis in having glabrous lemmas (sericious hairs on lower 1/2−3/4 in the latter).

Molecular DNA sequence analysis indicates M. ligularis falls within M. subg. Bealia and is polyphyletic (Fig. 1A). Perhaps, cryptic speciation followed by morphological convergence has occurred within M. ligularis, also suggested in Ehrharta Thund. and Eriochrysis P. Beauv. (Verboom et al. 2003; Welker et al. 2016).

Specimens examined

Peru. Amazonas: Chachapoyas, 1.5 km al SW of Chachapoyas, 2320 m, 24 May 1962, J.J. Wurdack 504 (US, USM); Ancash: Huaraz, Huascaran National Park, Quebrada Rajucolta, 77°22'W, 9°32'S, 4000 m, 17 Apr 1986, D.N. Smith, R. Valencia, M. Buddensiek 12192 (CPUN, MO); S of Huaraz, 28 km from Pachacoto towards La Union, 4500 m, 6 Apr 1988, S.A. Renvoize & S. Lægaard 5118 (CPUN, K); Huari, Cordillera Blanca, 24 km N of Huari on road towards San Luis, 3820 m, 22 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13871 (MO, US, USM); Huascarán. National Park, Quebrada Pachachaca, a lateral valley of Quebrada Rurichinchay, 77°16'W, 9°77'S, 3700 m, 12 Jun 1986, D.N. Smith, A. Gonzales & D. Maldonado 12562 (CPUN, MO); Prov. Pallasca, Hacienda Chalan, Mar 1949, A. Tito Ureña 7 (MOL); Recuay, Cordillera Blanca, 37 km E of Raquia on Route 02-014 on road towards Huarez, 3900 m, 20 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13816 (US, USM); 2 km SW of Conococha on Ruta 02-014. 10°8'18.2"S, 77°18'5.4"W, 4107 m, 21 Mar 2004, P.M. Peterson, N. Refulio Rodriguez, A. Cano, M. La Torre & I. Salinas 17902 (MO, US, USM); 3 km E of Conococha, 10°6'55.5"S, 77°16'20.2"W, 4050 m, 24 Mar 2004, P.M. Peterson & N. Refulio Rodriguez 17935 (MO, US, USM); Cordillera Negra, E slope of Cerro Pullicharca (Purac), ca. 1.5 km W of hwy 109 and then 3.6 km S of Tapacocha along Rio Santa, 9°55'39.4"S, 77°23'45.3"W, 3822 m, 9 Mar 2008, P.M. Peterson, R.J. Soreng, M. La Torre & J. Rojas Fox 21513 (US, USM); Cordillera Negra, 30 km from Huaraz towards Casma, Punta Callán, 4200 m, 7 Apr 1988, S.A. Renvoize & S. Lægaard 5162 (CPUN, K); Sihaus, 31 km N of Pomabamba on road towards Sihaus, 3780 m, 24 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13906 (MO, US, USM); Quebrada Huanca, 77°23'W, 9°55'S, 3950 m, 2 Jul 1985, D.N. Smith & M. Buddensiek 10970 (CPUN, MO); Yungay, W slope of Cordillera Blanca, Rio at E end of Lago Llanganuco, ca. 29 km ENE of new city of Yungay, Parque Nacional Huascaran, Sector Llanganuco, 9°4'8.9"S, 77°38'25.2"W, 3663 m, 16 Mar 2008, P.M. Peterson, R.J. Soreng, M. La Torre & J. Rojas Fox 21747 (US, USM); W slope of Cordillera Blanca on road to pass E of Lago Llanganuco and Yanama, ca. 37 km ENE of new city of Yungay, Parque Nacional Huascaran, Sector Llauganuco, 9°3'16.6"S, 77°35'57.6"W, 3931 m, 16 Mar 2008, P M. Peterson, R.J. Soreng, M. La Torre & J. Rojas Fox 21758 (US, USM); 37 km E of Yungay, 4200 m, 5 Apr 1988, S.A. Renvoize & S. Lægaard 5080 (CPUN, K). Apurimac: Aymaraes, 25 km NE of Chalhuanca on road towards Yanaca, at Paseo., 14°15'30.6"S, 73°12'6.9"W, 4300 m, 13 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16504 (US, USM). Arequipa: Caylloma, 15 km SE of Callalli on road towards Condoroma, 15°28'14"S, 71°22'26.9"W, 4610 m, 12 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18279 (MO, US, USM). Ayacucho: Huamanga, S of Ayacucho ca. 45 km on Hwy 3 toward Abancay, 13°20'27"S, 74°9'34.7"W, 4207 m, 16 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & D. Susanibar Cruz 20522 (US, USM); 68 km SW of Ayacucho on road towards Pisco, 13°20'5"S, 74°36'36.7"W, 4045 m, 22 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16659 (US, USM); Lucanas, 2 km SW of Putajasa, 14°8'15.9"S, 74°11'18.4"W, 3900 m, 24 Feb 2002, P.M. Peterson, A. Cano, M. La Torre, A. Ramírez & D. Susanibar Cruz 16225 (US, USM); 25 km E of Puquio on road towards Cusco, 14°37'40.3"S, 74°2'19.1"W, 4150 m, 12 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16454 (US, USM); 25 km NE of Villatambo on road towards Lucanas at Reserva “Pampa Galeras”. 14°40'46.2"S, 74°23'59.2"W, 3805 m, 8 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18179 (US, USM); 13 km E of Puquio at km 172 mark, 14°41'18.5"S, 74°4'26.8"W, 3730 m, 8 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18214 (MO, US, USM); Parinacochas, along arroyo near small rio above (north) of Laguna Parinacochas, 15°14'41"S, 73°44'20.3"W, 3300 m, 1 Mar 2002, P.M. Peterson, M. La Torre, A. Ramírez & D. Susanibar Cruz 16326 (US, USM). Cajamarca: Cajamarca, 21 km W of Central Plaza of Cajamarca at Cumbemayo (take Avenida Peru), 3600 m, 31 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 14014 (MO, US, USM); Cumbe Mayo, subiendo el curso del canal, 3500 m, 20 Mar 1988, I. Sánchez Vega 4692 (CPUN); Cumbe Mayo, west of Cajamarca. growing in seeping water, 3600 m, 27 Mar 1988, S.A. Renvoize, S. Lægaard & I. Sánchez Vega 4997 (CPUN, K).Cordillera Comullca, 57 km. from Cajamarca on road to Celendín,“Jalca” páramo, 3600 m, 26 Mar 1988, S.A. Renvoize & S. Lægaard 4964 (CPUN, K); Pampa de Guanico, ruta a Guagal, 17 May 1973, 3500 m, I. Sánchez Vega.1145 & J. Tejada Mayta (CPUN); desvío a Guagal, ruta a Celendín, 2700 m, 17 May 1977, I. Sánchez Vega 2027, W. Ruiz V. & J. Sánchez Vega.(CPUN); Dist. La Encañada. Cerro Negro, extremo SE de las pampas de Cerro Negro, 3480 m, 19 Jul 2003, M. Cabanillas Soriano 1548, M. Cabanillas Medina & M. Sánchez Montoya (CPUN); entre Cajamarca y La Encañada, 2700 m, 22 May 1974, I. Sánchez Vega 1302 & W. Ruiz Vigo (CPUN); Dist. La Encañada, Pampas de Cerro Negro, 3540 m, 12 Jul 2003, M. Cabanillas Soriano 1501, M. Cabanillas Medina & M. Sánchez Montoya (CPUN); Cajamarca to Bambamarca, on side road to Chugur, 88 km from Cajamarca, just below first mine, 3700 m, 20 Mar 1988, S.A. Renvoize, S. Lægaard & I. Sánchez Vega 4822 (CPUN, K); Las lagunas, 50 km from Cajamarca on road to Bambamarca, 4000 m, 29 Mar 1988, S.A. Renvoize & S. Lægaard 5030 (CPUN, K); Dist Cajamarca. Pampa Larga, al N de Yancocha, 3900 m, 14 May 1994, I. Sánchez Vega 7135, Homero Bazán & Alfonso Miranda (CPUN); Micuypampa, 62 km from Cajamarca towards Celendin, 2600 m, 26 Mar 1988, S.A. Renvoize & S. Lægaard 4963 (CPUN, K);Celendin, S of Cajamarca−Celendin Hwy, E of pass between provincia borders and ca. 11 km along road to Huagal, vic. La Honda, 7°5'15.6"S, 78°11'39.9"W, 3525 m, 28 Mar 2008, P.M. Peterson, R.J. Soreng & J. Montoya Quino 21912 (US, USM); San Miguel, 61 km N of Cajamarca on Hwy 3N towards Bambamarca, 3640 m, 16 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14915 (CPUN, MO, US, USM); San Pablo, 33 km NW of Cajamarca on road towards San Pablo via Porcon, 3510 m, 14 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14876 (CPUN, MO, US, USM). Cusco: Calca, 26 km E of Pisac on road to Colquepata, 13°23'2.1"S, 71°44'46.9"W, 4120 m, 18 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16602 (US, USM); Canchis, Dist. Marangani, Lay Raya, 14.46666S 71.016666W, 7 May 2003, L. Valenzuela, J. Farfán, I. Huamantupa, E. Suclli, & H. Coasaca 1970 (MO); Cusco, Sacsaihuamán, 3600 m, Apr 1944, C. Vargas C. 4167 (US); Espinar, alrededores de Yauri, 3900 m, 26 Mar 1956, C. Vargas C. 11213 (US); Espinar, Hda. C’achachi, 4200 m, 20 Mar 1956, C. Vargas C. 11160 (US); Paucartambo, 21 km NE of Paucartambo on road to Tres Cruces., 13°11'54.8"S, 71°38'40.5"W, 3460 m, 18 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16621 (US, USM); 1 km E of Mirador Tres Cruces and 35 km N of Paucartambo, 13°8'11.6"S, 71°37'40.3"W, 3625 m, 19 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16639 (US, USM); Quispicanchi, 23 km up new Hwy 28 from Urcos to Ccatcca (Catsa), ESE of Cusco ca. 45 air km, 13°39'39.5"S, 71°35'29.7"W, 4080 m, 19 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romashchenko 20564 (US, USM); Vilacabamba, Paltaybamba, Ayangate, 13.0494444S 72.7208334W, 2300 m, 10 Jun 2002, L. Valenzuela, E. Suclli, I. Huamantupa & F. Carazas 225 (MO). Huancavelica: Castrovirreyna, 30 km SW of Huancavelica along Rio Pucapampa, 12°56'10"S, 75°5'57.2"W, 4510 m, 8 Mar 2002, P.M. Peterson & O. Tovar 16399 (US, USM); Castrovirreyna, Choclococha, 4500 m, 5 May 1958, O. Tovar 2907 (US, USM); Castrovirreyna, Choclococha, 4700 m, 3 May 1958, O. Tovar 2854 (US, USM); 3 km S of Astobamba on road towards Pucapampa, 12°58'47.7"S, 75°5'27.4"W, 4540 m, 4 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18118 (MO, US, USM); 4 km S of Choclococha and 8 km N of Santa Ines, 13°10'44"S, 75°5'15.3"W, 4615 m, 5 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18145 (MO, US, USM); Huancavelica, 56 km S of Izacuchaca on road towards Huancavelica, 4020 m, 10 Apr 1997, P.M. Peterson & O. Tovar 14157 (US, USM);15 km NE of Huancavelica above Sachapite, 4100 m, 10 Apr 1997, P.M. Peterson & O. Tovar 14171 (US, USM); 12 km S of Huancavelica on road towards Santa Barbara, 4120 m, 11 Apr 1997, P.M. Peterson & O. Tovar 14191 (MO, US, USM); 13 km N of Huancavelica on road towards Palca, 12°43'9"S, 74°59'11.9"W, 4470 m, 2 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18098 (MO, US, USM); Huaytara, Rio Pampas, along Hwy 3 (old 24) 12 km NW of jct. with new Hwy 24 and 18 km SE of Santa Ines, SE of Pilpichaca, 13°19'24.2"S, 75°00'56.6"W, 4164 m, 13 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & D. Susanibar Cruz 20432 (US, USM); Occoro, entre Conaica y Tansiri, 4200 m, 2 Apr 1953, O. Tovar 1195 (US, USM); Occoro, 4200 m, 3 Apr 1953, O. Tovar 1214 (US, USM); Tayacaja, Hda. Alalay entre Mariscal Caceres y Pampas, 3900 m, 13 Apr 1953, O. Tovar 1333 (MO, US, USM); Tayacaja, 2 km E of Acostambo on road towards Izcuchaca, 12°22'3.7"S, 75°2'33.3"W, 3350 m, 1 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18087 (US, USM); Tayacaja, Patacancha, Conaica, 4100 m, 8 Apr 1961, O. Tovar 3131 (US, USM); Chascca, cerca a Conaica, 3800 m, 13 May 1956, O. Tovar 2588 (US, USM); Tayacaja, arriba de Hda. Toca, entre Calcabamba y Paucarbamba, 3800 m, 20 Apr 1954, O. Tovar 2021 (US, USM); Urubamba, Piri, 2860 m, 15 May 1948, C. Vargas C. 7208 (US). Junin: Junin, SE shore of Lago Chinchay Cocha (Junin) and 8 km S of Huayre, 4110 m, 7 Apr 1997, P.M. Peterson & O. Tovar 14097 (MO, US, USM); Tarma, Hacienda Casa Blanca, 18 air km SSE of Tarma, 4000 m, 27 Nov 1962, H.H. Iltis, C.M. Iltis, D. Ugent & V. Ugent s.n. (US); Yanli, La Oroya, 11°32'S, 75°53'W, 3700 m, 7 Jan 1983, D.N. Smith 2974 (MO, US); Yanli, Marcapomacocha, 4800 m, O. Velarde 8751 (US, USM). La Libertad: Bolivar, E side of Cerro Salumpuy, between Laplat and Unamen, WSW of Unamen, ca. 8 air km NW of Bolivar, 7°7'39.2"S, 77°46'9.9"W, 3390 m, 30 Mar 2008, P.M. Peterson, R.J. Soreng & J. Montoya Quino 21946 (US, USM); Pataz, cueva de Manachaqui, Parque Nacional Río Abiceo, 3600 m, 28 Feb 1998, B. León & K. Young 1116. (MO, USM); Santiago de Chuco, 23 km SW of Huamachuco on road towards Alto de Tamboras and Pampas, 3540 m, 29 Mar 1997, P.M. Peterson & N. Refulio Refulio 13966 (MO, US, USM). Lambayeque: Ferrenafe, 3300 m, 12 Sep 1985, A. Sagástegui A., D. Skillman, J. Mostacero L. & L. Ramírez V. 12812 (MO); Laguna Tembladera, Uyurpampa, 3320 m, 25 Aug 1993, S. Llatas Quiroz 3359 (MO). Pasco: Pasco, 4 km NE of Huayllay on road towards Canchacucho, 10°58'20.8"S, 76°19'18"W, 4160 m, 31 Mar 2004, P.M. Peterson & N. Refulio Rodriguez 18067 (MO, US, USM); plains ca. 8 km W of NW arm of Laguna de Junin, S side of Rio Colorado and E of new Hwy and railroad tracks, 12 km NE of Huayllay on Hwy 18, 10°55'51.9"S, 76°18'8.6"W, 4141 m, 5 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romashchenko 20314 (US, USM). Piura: Ayabaca, Ruinas de Aypate, 2700 m, 21 May 1996, V. Quipuzcoa S. 544, O. Angulo Z. & R. Yahuana R. (HAO, MO); Huancabamba, 23 km E of Sondor on road towards Tabaconas, 2740 m, 31 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 15133 (CPUN, MO, US, USM). Puno: Abra la Raya, along railroad between Santa Rosa and Marangani, 4300 m, 18 May 1985, J.C. Solomon 2920 (MO); Azangaro, Checayani, NE of Azangaro, 3900 m, 27 Mar 1957, H. Ellenberg 426 (US); Chuquibambilla, Florez 13 (WS); Granja Salcedo, Apr 1936, J. Sonkup 112 (US); Cerro Santa Barbara, 3700 m, 15 May 1958, O. Tovar 3071 (US, USM); Huerta, N of Puno, 3900 m, 22 Mar 1957, H. Ellenberg 242 (US); Pucará, Pampa, 3890 m, Apr 1964, A. Vera 105 (COL); alrededores de Puno, 3870 m, 16 Apr 1965, A. Vera 204 (COL); quebrada en los alrededores de Puno, 3850 m, 1 Oct 1965, A. Vera 340 (COL); Chucuito, 3 km NE of Zepita on road towards Copani, 3820 m, 5 Mar 1999, P.M. Peterson, N. Refulio Rodriguez & F. Salvador Perez 14633 (US, USM); 2 km S of Huacullani, 4000 m, 6 Mar 1999, P.M. Peterson, N. Refulio Rodriguez & F. Salvador Perez 14659 (MO, US, USM); Lampa, NW end of Laguna Lagunillas, 20 air km W of Santa Lucia, N and S sides of new Hwy 30 to Arequipa, 74 air km WSW of Juliaca, 15°41'1.7"S, 70°48'5.4"W, 4185 m, 31 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & M.S. Gonzalez Elizondo 20735 (US, USM); Melgar, ca. 7 km WNW of Santa Rosa on Hwy 3 and 1 km W toward Quishuara, along Rio Santa Rosa, 14°35'54.9"S, 70°51'34.7"W, 4002 m, 23 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romashchenko 20606 (US, USM); Puno, 2 km N of Laraquerion road towards Puno, 16°6'59.1"S, 70°1'59.1"W, 3940 m, 18 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18328 (MO, US, USM); San Roman, 21 km W of Santa Lucia and 5 km E of Puente Cañuma (Laguna Lagunillas), 15°40'4.1"S, 70°47'4.4"W, 4260 m, 20 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18345 (MO, US, USM). San Martín: Mariscal Caceres, 7°00'01"S, 77°00'3"W, 3350 m, 18 Jul 1987, K. Young & B. León 4793 (MO, USM).

Muhlenbergia maxima Lægaard & Sánchez Vega, Nordic J. Bot. 10: 439. 1990.

Fig. 2F−H

Type

Peru, Prov. Cajamarca, Choten between Paso El Gavilán and San Juan at km 153 on the road to the coast, 2900 m, 29 May 1984, I. Sánchez Vega & Ruiz Vigo 3561 (holotype: CPUN!; isotypes: AAU!, K!, US!, USM!).

Description

Loosely caespitose perennials. Culms 100−140 cm tall, erect, rigid, terete, ca. 2−3.2 mm diameter near base with 3 or 4 glabrous to pubescent nodes; internodes terete above. Leaf sheaths longer than the internodes, mostly basally inserted, compressed-keeled near base, becoming fibrous with age, scaberulous, finely striate; ligules 3−5 mm long, apex irregularly toothed to lacinate, margins entire and extended above to form auricles; blades 25−45 cm long, 2.8−4 mm wide, flat to folded, striate, scabrous, apex attenuate, midvein prominent. Panicles 30−46 cm long, 3−6 cm wide, narrow; branches 6−11 cm long, scabrous, ascending, appressed to loosely spreading, mostly floriferous to base, except on lowest branches; pedicels mostly shorter than the spikelets. Spikelets 2.5−2.8 mm long, 1-flowered, greenish with reddish-purple tinting; glumes 2.2−2.6 mm long, almost equal or shorter than the floret, hyaline to membranous, faintly 1-veined, subequal, the lower usually slightly shorter, glabrous to scattered pubescent, scaberulous; lemmas 2.5−2.8 mm long, ovate, 3-veined, awned, with scattered sericeous hairs more numerous along the veins, scaberulous, the callus pilose, the flexuous awn inserted just below the obtuse to acute apex, the awn 4−9 mm long; paleas about as long as the lemma, faintly 2-veined, sericeous between the veins below; lodicules about 0.1 mm long, truncate, glabrous; stamens 3; anthers 1.3−1.8 mm long, purple. Caryopses 1.4−1.7 mm long, fusiform, brownish.

Distribution

A Peruvian endemic known only from Amazonas and Cajamarca departments.

Ecology

Rocky slopes near rivers and grassy slopes in disturbed ground along roads associated with Acacia, Begonia, Cortaderia bifida, C. jubata, Desmodium, Dodonaea viscosa Jacq., Hyptis, Lepechinia, Oxalis, Puya, Salvia and Schizachyrium; 2100−2900 m.

Comments

Muhlenbergia maxima is a member of M. subg. Trichochloa (Peterson et al. 2010b). Muhlenbergia inaequalis Soderstr. endemic to Colombia and Venezuela and M. lehmanniana Henr. ranging from Costa Rica to Colombia (Lægaard and Sánchez Vega 1990; Giraldo-Cañas and Peterson 2009) are morphologically similar to M. maxima. Muhlenbergia maxima differs from M. inaequalis and M. lehmanniana in having shorter lemmatal awns and a longer ligule than M. inaequalis (0.5−1.5 mm long) and a shorter ligule than M. lehmanniana (1−2.5 cm long). There is not much genetic variation among all members of M. subg. Trichochloa in Peterson et al. (2010a) and a detailed population genetic study of these three South American species is needed to interpret their evolutionary history.

Specimens examined

Peru. Amazonas: 27 km from Balsas towards Leymabamba, 2250 m, 23 Mar 1988, S.A. Renvoize & S. Lægaard 4908 (CPUN, K); 66 km from Leymebamba towards Balsas, 2100 m, 25 Mar 1988, S.A. Renvoize & S. Lægaard 4935 (CPUN, K, MO, US). Cajamarca: Prov. Cajabamba, 14 air km WSW of Cajabamba and 2.5 km on road W of Araqueda, 7°39'9.1"S, 78°9'58.9"W, 2242 m, 23 Mar 2008, P.M. Peterson & R.J. Soreng 21853 (MO, US, USM); Prov. Cajamarca, S of Paso El Gavelán, ca. 10 air km S of Cajamarca, just above km post 150 on hwy 8 above San Juan, 7°15'37.2"S, 78°30'34.5"W, 2544 m, 26 Mar 2008, P.M. Peterson, R.J. Soreng & I Sánchez Vega 21884 (US, USM); Dist. San Juan, entre San Juan y Paso el Gavilán, 2650 m, 30 May 2003, I. Sánchez Vega 11965, M. Sánchez M. y R. Cueva R. (CPUN, HAO); Celendin, Marañón River Valley, Chachapoyas−Cajamarca road, 2100 m, 28 May 1984, D.N. Smith & J.M. Cabanillas S. 7271 (MO, US).

Muhlenbergia microsperma (DC.) Kunth, Révis. Gramin. 1:64. 1829.

Fig. 7E−H

Trichochloa microsperma DC., Cat. Pl. Horti Monsp. 151. 1813. Muhlenbergia microsperma (DC.) Trin., Gram. Unifl. Sesquifl. 193. 1824, nom. inval. Type: Mexico, cultivated at the botanical gardern at Montpellier from seeds collected in Mexico and distributed by the Botanical Garden of Madrid, M. Sésse & J.M. Mociño s.n. (holotype: MPU; isotypes: G-00099434 [image!], P!, US fragm. ex P!).

Agrostis microsperma Lag., Gen. Sp. Pl. 2. 1816. Type: Mexico, plants grown at H.R. Matritensis (= Herbario del Real Jardín Botánico de Madrid, see Sutherland 1997) from seeds collected by M. Sessé & J.M. Mociño in Nueva Espania, Oct, 1806, M. Sessé & J.M. Mociño s.n. (lectotype, here designated: SEL-H10620 [image!]).

Podosemum debile Kunth, Nov. Gen. Sp. (quarto ed.) 1: 128. 1816. Trichochloa debilis (Kunth) Roem. & Schult., Syst. Veg. 2:385. 1817. Muhlenbergia debilis (Kunth) Trin., Gram. Unifl. Sesquifl. 193, t. 5, f. 18. 1824. Type: Ecuador, Prov. Pichincha, Quito, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P-Bonpl!; isotypes: B-W, P!, US-91924 fragm. ex P-Bonpl!).

Podosemum setosum Kunth, Nov. Gen. Sp. (quarto ed.) 1:129. 1816. Trichochloa setosa (Kunth) Roem. & Schult., Syst. Veg. 2:386. 1817. Agrostis setosa (Kunth) Spreng., Syst. Veg. 1:262. 1825. Muhlenbergia setosa (Kunth) Trin., Gram. Unifl. Sesquifl. 193, t. 5, f. 22. 1824. Muhlenbergia setosa (Kunth) Kunth, Révis. Gramin. 1:63. 1829, isonym. Type: Mexico, between Gueguetoque and Tula, Aug, F.W.H.A. Humboldt & A.J.A. Bonpland 4174 (holotype: P-Bonpl!; isotypes: B-W, US-91917 fragm. ex P-Bonpl!).

Muhlenbergia purpurea Nutt., J. Acad. Nat. Sci. Philadelphia, ser. 2, 1:186. 1848. Type: U.S.A., California, Santa Barbara Co., Santa Barbara and Santa Catalina Island, Gambel s.n. (holotype: K!).

Muhlenbergia ramosissima Vasey, Bull. Torrey Bot. Club 13(12):231. 1886. Type: Mexico, Chihuahua, SW Chihuahua, Aug–Nov 1885, E. Palmer 158 (lectotype: NY-00381467! designated by Hitchcock, N. Amer. Fl. 27:441. 1935, but without indicating the specific specimen; Peterson and Annable, Syst. Bot. Monogr. 31:61. 1991, indicated the specific specimen; isolectotypes: LE!, GH-00024043 [image!], MO-2974152!, NY-00381468 [image!], P-00644106!, PH-00018772 [image!], US-995580!, W-19160027660 [image!]).

Description

Caespitose annuals, sometimes appearing as short-lived perennials. Culms 10–80 cm tall, often geniculate at the base, slender, often striate, much branched near the base, scaberulous below the nodes; internodes 1.8–8.6 mm long, mostly scaberulous or smooth. Leaf sheaths 2.2–6.6 mm long, commonly shorter than the internodes, glabrous, smooth or scaberulous; ligules 1–2 mm long, membranous to hyaline, decurrent, margins often extended, apex truncate to obtuse; blades 3–8.5(–10) cm long, 1–2.5 mm wide, flat or loosely involute, scabrous below, strigulose above, often deciduous with age. Panicles 6.5–13.5 cm long, 1–6.5 cm wide, open and not densely flowered, often purplish; primary branches 1.6–4 cm long, ascending or diverging up to 80° from the rachises, spikelet-bearing to the base; pedicels 2–6 mm long, appressed to divaricate, antrorsely scabrous. Cleistogamous panicles with 1–3 spikelets present in the axils of the lower sheaths. Spikelets 2.5–5.5 mm long; glumes 0.4–1.3 mm long, exceeded by the florets, 1-nerved, obtuse, often minutely erose; lower glumes 0.4–1 mm long; upper glumes 0.6–1.3 mm long; lemmas 2.5–3.8(–5.3) mm long, narrowly lanceolate, mostly smooth, scaberulous distally, lower 1/2 of the margins and midveins, the hairs 0.2–0.5 mm long, the callus hairy, apices acuminate, often bidentate, awned, awns 10–30 mm long, straight to flexuous; paleas 2.2–4.8 mm long, narrowly lanceolate, acuminate; anthers 0.3–1.2 mm long, purplish. Caryopses 1.7–2.5 mm long, fusiform, reddish-brown. 2n = 20, 40, 60.

Distribution

Muhlenbergia microsperma occurs in Hawaii, south-western U.S.A., Mexico, Guatemala, Colombia, Venezuela, Ecuador (including the Galapagos Islands), Peru and Bolivia (Peterson and Annable 1991).

Ecology

Rocky slopes, rock outcrops, sandy drainages, cliffs and disturbed roadsides usually in desert scrub vegetation with Acacia, Aristida adcensionis L., Baccharis, Bothriochloa, Bombacaceae, Cactaceae, Dodonaea viscosa, Eragrostis nigricans, E. lugens Nees, Fucraea, Heliotropium, Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult., Lantana, Muhlenbergia rigida, Pitcairnia, Prosopis, Puya, Salvia, Schinus molle and Schizachyrium; 1150−3500 m.

Comments

Muhlenbergia microsperma can sometimes be confused with M. romaschenkoi and differs from it by having cleistogamous panicles in the axils of the lower sheaths and shorter, obtuse glumes, 0.4–1.3 mm long (glumes acute to acuminate, 2–2.8 mm long in M. romaschenkoi).

In a molecular DNA sequence study, M. microsperma forms a strongly supported clade with two other annuals, M. appressa C.O. Godding and M. brandegei C.G. Reeder, all members of M. subg. Muhlenbergia (Fig. 1B; Peterson et al. 2010b). These three species produce cleistogamous spikelets in the axils of the lower culm branches, enclosed by a sheath (Peterson and Annable 1991). Cleistogamous spikelets appear to have evolved twice within Muhlenbergia, once in M. subg. Muhlenbergia within the M. appressaM. brandegeiM. microsperma clade and once in M. sect. Pseudosporobolus in M. cuspidata (Torr. ex Hook.) Rydb. (Morden and Hatch 1984; Peterson et al. 2010b).

Specimens examined

Peru. Ancash: at the Rio Yanamayo crossing, 57 km N of San Luis on road towards Pomabamba, 2540 m, 24 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13896 (US, USM); 68 km from Casma towards Huaraz, 1700 m, 4 Apr 1988, S.A. Renvoize & S. Lægaard 5047 (CPUN, K); Pallasca, divide between Rio Conchucos and Rio Plata, low end of road up to Pampas from Rio Conchucos, above Mollapata crossing of Rio Tablachaca, 8°12'9.1"S, 77°56'20.6"W, 2233 m, 21 Mar 2008, P.M. Peterson & R.J. Soreng 21833 (MO, US, USM). Apurimac: Aymaraes, 16 km NW of Chalhuanca, 14°10'16.4"S, 73°19'26.1"W, 2670 m, 14 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16511 (US, USM); Chincheros, canyon of Rio Pampas, between Ayacucho and Abancay on hwy 7, 7 km S of bridge over Rio Pampas, 13°28'42.1"S, 73°49'32"W, 2049 m, 17 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romaschenko & D. Susanibar Cruz 20535 (MO, US, USM). Ayacucho: alrededores de Huanta, 2400 m, 30 Apr 1964, O. Tovar 4829 (US, USM). Cajamarca: Cajabamba, WSW of Cajabamba, 14 air km E of Araqueda, 7°39'9.1"S, 78°9'58.9"W, 2242 m, 23 Mar 2008, P.M. Peterson & R.J. Soreng 21855 (US, USM); Cajamarca, Cerro Huacaris, valle de Cajamarca, 1 Jun 1971, I. Sánchez Vega 726, W. Ruiz Vigo & J. Tejada (CPUN); Cajamarca, abajo de San Juan, siguiendo la carretera Cajamarca–Pacasmayo, 1900 m, 18 May 1986, I. Sánchez Vega 4072 (CPUN); Cajamarca, entre San Juan y Magdalena, 1800 m, 15 May 1971, I. Sánchez Vega 657 & W. Ruiz Vigo (CPUN); entre Chancay y Valle de Condebamba, 2600 m, 6 May 1972, I. Sánchez Vega 944, W. Ruiz Vigo & M. Malpica R. (CPUN); Dist. Ichocán, en el Arboretum Ichocán II de CICAFOR, entre la localidad de Chacay y Valle Condebamba, 2450 m, 29 Mar 1981, I. Sánchez Vega 2409, V. Torrel & E. Medina (CPUN); Celendin, Marañón River Valley, Chachapoyas−Cajamarca road, 1900 m, 28 May 1984, D.N. Smith & J. Cabanillas 7254 (MO, US); Chota, Dist. Cochabamba, a 1km sobre la carretera Cochabamba–Cutervo, 1720 m, 15 Jun 1980, I. Sánchez Vega 2288 (CPUN). Cusco: Anta, Sisal, Limatambo, 2300 m, 15 Mar 1963, C. Vargas C. 14327 (US, USM); Anta, Sisal−Cunyaee, 2100 m, 14 May 1965, C. Vargas C. 16316 (US, USM). Huancavelica: Salcabamba−Colcabamba, camino a Pampas, 2000 m, 22 Apr 1962, O. Tovar 3834 (US, USM); Tayacaja, alrededores de Mayoc, 2400 m, 9 Apr 1966, O. Tovar 5589 (US, USM). Huánuco: Huánuco, W side of canyon of Rio Huallaga, S of Ambo, 7 km on hwy 3 towards Cerro de Pasco, 10°11'49"S, 76°9'54"W, 2345 m, 6 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20326 (US, USM); Huánuco, 2125 M, 25 Apr 1923, J.F. Macbride 3514 (F, US); 5 Apr 1923, J.F. Macbride 3217 (F, US). La Libertad: Bolivar, 4.6 air km NW of Longotea, SE of San Vicente on road from Balsas to Longotea, 7°0'38"S, 77°54'15.2"W, 2058 m, 31 Mar 2008, P.M. Peterson, R.J. Soreng & J. Montoya Quino 21970 (MO, US, USM); Otuzco, Quirrpe−Membrillar, 1150 m, 7 Dec 1952, A. López Miranda 927 (US); Santiago de Chuco, 22 km E of Huamachuco on road towards Sarin above Rio Chusgon, 2500 m, 29 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13973 (US, USM). Lima: Canta, 2 km SE of San Jose Canta, 11°30'2"S, 76°40'23.4"W, 2232 m, 27 Mar 2004, P.M. Peterson & N. Refulio Rodriguez 17985 (MO, US, USM); Huarochiri, Matucana, 2430 m, 12 Apr 1922, J.F. Macbride & Featherstone 392 (F, US); Huarochiri, km 70 carretera Lima−Oroya, 1800 m, 15 May 1963, R. Ferreyra 14892 (US, USM); km 68, cerca Surco, entre Chosica y Matucana, 1400 m, 27 Mar 1955, R. Ferreyra 10498 (US, USM); km 72 de la carretera Lima−Oroya, cerca de Surro, 1800 m, 14 May 1948, R. Ferreyra 3485 (MOL, US, USM); Prov. Lima, above Paya, E. Asplund 10825 (NY). Piura: Huancabamba, 10 km N of Sondor and 3 km S of Huancabamba, 1860 m, 1 Apr 2000, P.M. Peterson & N. Refulio Rodriguez 15167 (CPUN, MO, US, USM). Tacna: Zarata, Sitiqui, 3500 m, 7 Apr 1959, C. Vargas C. 12588 (US, USM).

Muhlenbergia monandra Alegría & Rúgolo, Darwiniana 39(1–2): 20, 22, f. 1–3.

Fig. 10A−M

Type

Peru, Depto. Lima, Prov. Canta, 5 km arriba de San José en camino a Huamantanga, frente a Apio, 2700 m, 21 May 1999, A. Granda Paucar & J.J. Alegría Olivera 2230 (holotype: MOL; isotypes: BRIT-23827 [image!], SI! [SI-016006 image!], TEX, US-3376226! [US-00901642 image!], USM-000747 [image!]).

Description

Tufted annuals. Culms 4−25 cm tall, 0.3−0.7 mm in diameter near base, erect to decumbent, branching below, glabrous, 2 or 3 glabrous nodes, scaberulous below the nodes; internodes 0.5−9 cm long. Leaf sheaths 0.5−4.7 cm long, usually shorter than the internodes, compressed, mostly glabrous, scaberulous near the summit, margins scarious; ligules 1−3 mm long, hyaline, decurrent, apex truncate to obtuse, lacinate to irregularly dentate; blades (0.5−)1−8 cm long, 0.7−3.6 mm wide, flat or loosely folded, finely pilose above and scabrous below, margins scabrous, apex mostly acuminate, rarely acute. Panicles (0.5−)1−7 cm long, 2−9 mm wide, tightly spiciform, often interrupted below, elliptic to oblong, terminal and axillary, often partially included in the sheath below; primary branches 4−15 mm long, tightly ascending-appressed, verticillate below with 5−10 per node, scabrous; pedicles 0.1−1.2 mm long, shorter than the spikelets, scabrous. Spikelets 3.4−4.6 mm long, 1-flowered, tightly carinate, cleistogamous; glumes 3.5−4.7 mm long, longer than the floret, nearly equal in length, membranous, linear lanceolate, 1-veined, scaberulous along the midvein, apex acuminate, mucronate, the mucro 0.2−0.7 mm long; lemmas 1.5−2.1 mm long, hyaline to membranous, ovate, 3-veined, the lateral veins faint, mottled with irregular plumbeous areas, sparingly appressed pilose, the hairs 0.2−0.4 mm long, apex truncate to obtuse, subapically awned, the awns 1.2−5 mm long, straight; callus pilose; paleas 1.4−2 mm long, hyaline, ovate, sparingly pilose, apex truncate, the veins extending as mucros up to 0.2 mm long; lodicules 0.1−0.2 mm long, truncate; stamen 1, anthers 0.3−0.6 mm long, whitish to yellow. Caryopses 1−1.6 mm long, ovoid, laterally flattened, light brown.

Figure 10. 

A−M Muhlenbergia monandra Alegría & Rúgolo A habit B ligule C two spikelets D glume base and rachilla E lemma, dorsal view F floret, side view G floret, ventral view H apex of lemma with two small teeth I palea and caryopsis, lateral view J lodícules K caryopsis, dorsal view L caryopsis, lateral view M caryopsis, ventral view. Drawings from the holotype collection Granda Paucar & Alegría Olivera 2230.

Distribution

A Peruvian endemic known only from near San Jose de Canta, Peru.

Ecology

This species occurs on gravelly slopes among xerophytic scrub vegetation with Bouteloua simplex, Eragrostis mexicana subsp. virescens (J. Presl) S.D. Koch & Sánchez Vega, Muhlenbergia bryophilus, Urochloa sp., Veronica sp. and Festuca myruos between 2700 and 2800 m.

Comments

Molecular DNA sequence analysis indicates Muhlenbergia monandra is an unsupported sister to the M. atacamensis -M. ligulata-M. subbiflora clade in M. subg. Pseudosporobolus (Fig. 1B).

Specimens examined

Peru. Lima: Prov. Canta, 8 km SW of San Jose Canta towards Huamantango, 11°31'10.0"S, 76°42'16.3"W, 2770 m, 28 Mar 2004, P.M. Peterson & N. Refulio Rodriguez 17990 (MO, US, USM); entre Huamantanga y Puruchuco, 2800 m, 1 May 1994, J.J. Alegría Olivera 739 (MOL, SI).

Muhlenbergia peruviana (P. Beauv.) Steud., Nomencl. Bot. (ed. 2) 1:41. 1840.

Fig. 11A−D

Clomena peruviana P. Beauv., Ess. Agrostogr. 28, t. 7, f. 10; t. 3, f. 20. 1812. Agrostis peruviana (P. Beauv.) Spreng., Syst. Veg. 1:262. 1825. Type: Peru, M. Thibaut s.n. (holotype: P!; isotype: E-00373717 [image!]).

Clomena peruviana var. pulvinata Nees, Gramineae 12–13. 1841. Muhlenbergia peruviana var. pulvinata (Nees) Nees & E. Mey. ex Kuntze, Revis. Gen. Pl. 3(3):357. 1898. Type: Peru, Lago Titicaca, Apr, J.F.J. Meyen s.n. (holotype: B; isotype: US-3376134 fragm. ex B!).

Muhlenbergia nana Benth., Pl. Hartw. 262. 1846. Type: Ecuador, Mt. Cotopaxi, 1843, Hartweg 1458 (holotype: K!; isotypes: BAA-1629!, K!, LE!, P!, US-91916 fragm. ex P!, US-995896 fragm. ex P-STEUD & fragm. ex BR!).

Muhlenbergia pusilla Steud., Syn. Pl. Glumac. 1:177. 1854. Type: Mexico, México, Valley of Toluca, Oct. 1827, J.L. Berlandier 1141 (holotype: P!; isotypes: BAA-1635!, K!, MO-2974185!, P!, US-1084517!, US-2561239!, US-91910 fragm. ex P!).

Epicampes bourgeaei E. Fourn., Mexic. Pl. 2: 88. 1886. Type: Mexico, Veracruz, Escamala, Refrou D’Orizaba, 26 Aug 1866, E. Bourgeau 2973 (holotype: P!; isotype: US-A0865984 fragm ex P!).

Muhlenbergia bourgeaei E. Fourn., Mexic. Pl. 2:86. 1886. Epicampes bourgeaei (E. Fourn.) M.E. Jones, Contr. W. Bot. 14:7. 1912, nom. illeg. hom.Type: Mexico, Valle de Mexico, Desierto Viejo, 3 Nov 1865, M. Bourgeau 1309 (lectotype: P! designated by Peterson and Annable, Syst. Bot. Monogr. 31:73. 1991; isotype: US-87243 fragm. ex P!).

Muhlenbergia pulcherrima Scribn. ex Beal, Grass. N. Amer. 2:240. 1896. Type: Mexico, Chihuahua: Sierra Madres, dry ledges of porphyry, 30 Sep 1887, C.G. Pringle 1416 (holotype: MSC!; isotypes MO-3727978!, NY!, US-995494!, VT!).

Muhlenbergia peruviana var. elatior Kuntze, Revis. Gen. Pl. 3(2): 357. 1898. Type: Bolivia, Tunarigebirge, 3000 m, May 1892, Kuntze s.n. (lectotype: NY! designated by Peterson and Annable, Syst. Bot. Monogr. 31:73. 1991: isotype: fragm. & photo US!).

Muhlenbergia peruviana var. subcaespitosa Kuntze, Revis. Gen. Pl. 3(3):357. 1898. Type: Bolivia, Tunari Mts., 4600 m, 4 May 1892, Kuntze s.n. (lectotype: NY! designated by Peterson and Annable, Syst. Bot. Monogr. 31:73. 1991).

Muhlenbergia peruviana fo. versicolor Kuntze, Revis. Gen. Pl. 3(3):357. 1898. Type: Bolivia, Tunarigebirge, 3000 m, May 1892, Kuntze s.n. (lectotype: NY! designated by Peterson and Annable, Syst. Bot. Monogr. 31:73. 1991; isotype: US fragm. ex NY!).

Muhlenbergia peruviana fo. viridis Kuntze, Revis. Gen. Pl. 3(3):357. 1898. Type: Bolivia, Puna, 4000 m, 11 Mar 1892, Kuntze s.n. (lectotype: NY! designated by Peterson and Annable, Syst. Bot. Monogr. 31:73. 1991).

Muhlenbergia herzogiana Henrard, Meded. Rijks-Herb. 40:58. 1921. Type: Bolivia, Cordillera de Santa Bonita, Jun 1911, T. Herzog 2226 (holotype: L!; isotypes: US-87248 fragm. ex L!, US-1161342!, W-1926-23724!).

Description

Tufted annuals. Culms 3–27 cm tall, erect, glabrous. Leaf sheaths usually longer than the internodes, smooth or scabridulous; ligules 1.5–3 mm long, membranous, acute; blades 1–5 cm long, 0.6–1.5 mm wide, flat to involute, smooth or scabridulous abaxially, sometimes shortly pubescent adaxially. Panicles 2–8 cm long, 0.3–3.4 cm wide, contracted or open; primary branches 1–5 cm long, diverging up to 80° from the rachises; pedicels 0.4–5 mm long, smooth or scabrous. Spikelets 1.4 4.2 mm long, 1-flowered; glumes smooth or scabridulous; lower glumes 0.8–2.8 mm long, narrow to broadly lanceolate, 1-veined, acute, often awn-tipped; upper glumes 0.9–3 mm long, wider than the lower glumes, lanceolate, 3 (2)-veined, truncate to acute, 2- or 3-toothed; lemmas 1.4–4.2 mm long, ovate, widest near the base, purplish mottled with dark green areas, hairy on the calluses and lower 2/3 of the lemma bodies, hairs to 0.5 mm long, apices acuminate, usually bifid and awned from between the teeth, teeth to 0.5 mm long, awns 3–10 mm long, flexuous, purplish; paleas 1.3–3.8 mm, narrowly lanceolate, acuminate to subacute; anthers 0.5–1 mm long, purplish to yellowish. Caryopses 1–1.6 mm long, fusiform, brownish. 2n = 30.

Figure 11. 

A−D Muhlenbergia peruviana (P. Beauv.) Steud A habit B ligule C glumes D floret E, F Muhlenbergia phalaroides (Kunth) P.M. Peterson E panicle F spikelet. Drawings A−D from Peterson and Annable (1991) drawn from P.M. Peterson & C.R. Annable 4739 (WS) E, F from Giraldo-Cañas and Peterson (2009) drawn from S. Lægaard 71419 (AAU).

Distribution

Muhlenbergia peruviana occurs in Arizona and New Mexico, U.S.A, throughout Mexico to Guatemala and then in Argentina, Bolivia, Chile, Ecuador and Peru (Peterson and Annable 1991).

Ecology

Grassy flats, open gravelly flats, rock outcrops, sandy washes, gravelly drainages, wet or dry meadows, canyons, gravelly or sandy slopes, valleys, shores along lakes, open ridgetops and disturbed road cuts associated with Aciachne pulvinata Benth., Anatherostipa, Berberis, Calamagrostis spp., Colletia spinosissima, Ephedra, Festuca orthophylla Pilg., Festuca spp., Jarava, Juncus, Lepidophyllum, Luzula, Margyricarpus, Monnina, Muhlenbergia spp., Nassella, Plantago, Poa spp., Polylepis, Puya, Pycnophyllum, Salvia oppositiflora Ruiz & Pav., Stevia and Tagetes; 3000−4900 m.

Comments

As treated here, Muhlenbergia peruviana includes (as synonyms) what was sometimes identified as M. pulcherrima Scribn. ex Beal (south-western U.S.A. and northern Mexico) and M. pusilla Steud. (central Mexico to Guatemala). There are many more morphological forms than just these and since the only chromosome count of this species suggests triploidy (2n = 3× =30), perhaps this species is apomictic (Reeder 1968). We believe apomixis is occurring in this species but it it not obligate and that gene flow takes place sporadically to form intermediates maintained by asexual seed formation (Peterson and Annable 1991).

In a molecular DNA sequence analysis, Muhlenbergia peruviana is sister to M. crispiseta Hitchc., another annual known only from Texas and north-central Mexico and this pair is embedded in the strongly supported M. subg. Clomena clade (Peterson et al. 2010b; Fig. 1B). Members of M. subg. Clomena possess spikelets with upper glumes that are 3-veined and often 3-toothed and individuals with a densely caespitose habit (Peterson et al. 2010b). Muhlenbergia peruviana can be separated from M. crispiseta in having irregularly flexuous, purplish awns (versus sinuous-wavy, crisped and curled, olive-green awns in M. crispiseta) and narrow, gradually acuminate lemmas (versus lemmas that are plump near middle) [Peterson and Annable 1991]. In our current DNA-derived phylogeny, M. crispiseta falls within the M. peruviana clade (Fig. 1B). However, rps3, the single marker we have for M. crispiseta, is not variable enough to distinguish these two species that are easily separated morphologically. In the future, we hope to clarify this with a full set of markers for M. crispiseta.

Specimens examined

Peru. Amazonas: Prov. Chachapoyas, Cerros Calla Calla, 3100 m, 19 Jun 1964, D.C. Hutchison & J.K. Wright 5756 (LIL, MO). Ancash: Cordillera Blanca, 4 km north of Recuay, 3400 m, 6 Apr 1988, S.A. Renvoize & S. Lægaard 5101 (CPUN, K); Cordillera Negra, 3 km N of Punta Callán, W of Huaraz, 4400 m, 7 Apr 1988, S.A. Renvoize & S. Lægaard 5171 (CPUN, K); Cordillera Negra, 30 km from Huaraz towards Casma, Punta Callán, 4200 m, 7 April 1988, S.A. Renvoize & S. Lægaard 5166 (CPUN, K); Pariarracra, Pampa de Lampas, 4160 m, 2 May 1952, E. Cerrate 1465 (MOL); Prov. Bolognesi, Capillapunta, 3350 m, 14 Apr 1949, R. Ferreyra 5716 (MOL, USM); Prov. Bolognesi, cerros al E de Chiquián, 3500 m, 10 May 1950, R. Ferreyra 7345 (US, USM); Prov. Bolognesi, Matarragra, cerro al NO de Chiquián, 3560 m, 8 Apr 1949, R. Ferreyra 5633 (US, USM); Prov. Bolognesi, Shincush, arriba de Chiquián, 4000 m, 19 Apr 1949, R. Ferreyra 5624 (US, USM); Carhuaz, Cordillera Negra, E slope, ca. 22 km SW of Shupluy, 09°17'19.7"S, 77°44'39.3"W, 3770 m, 13 Mar 2008, P.M. Peterson, R.J. Soreng, M.I. La Torre & J.V. Rojas Fox 21655 (US, USM); Recuay, Cordillera Blanca, 37 km E of Raquia on Route 02-014 on road towards Huarez, 3900 m, 20 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13818 (MO, US, USM); Recuay, Cordillera Negra W slope N of Quebrada Parin, 23 km NE of Cotaparaco on road to pass above Lago Ututo and Utcuyacu, 09°55'10.7"S, 77°32'02.2"W, 4216 m, 10 Mar 2008, P.M. Peterson, R.J. Soreng, M.I La Torre & J.V. Rojas Fox 21564 (US, USM); Recuay, Cordillera Negra, en cima de Caraz, 4300 m, A. Weberbauer 3098 (MOL); Huaraz, Huascarán National Park, quebrada Llaca, north side of valley, 9°27'S, 77°27'W, 4350 m, 25 May 1986, D.N. Smith 12428 (CPUN, MO); Recuay, quebrada Huanca, 9°55'S, 77°23'W, 3950 m, 2 Jul 1985, D.N. Smith & M. Buddensiek 10959 (CPUN, LPB, MO); Recuay, Huascarán National Park, mouth of quebrada Quenua Ragra, 10°2'S, 77°15'W, 4200 m, 10 May 1985, D.N. Smith, R. Valencia & A. Gonzales 10624 (CPUN, MO); Huari, Huascarán National Park, south side of quebrada Carhuazcancha, 9°28'S, 77°15'W, 3790 m, 6 May 1986, D.N. Smith, R. Valencia, A. Gonzales & M. Buddensiek 12294 (CPUN, MO); Recuay, 2 km SW of Conococha on Ruta 02-014, 10°8'18.2"S, 77°18'5.4"W, 4107 m, 21 Mar 2004, P.M. Peterson, N. Refulio Rodriguez, A. Cano, M.I. La Torre & I. Salinas 17903 (US, USM); Recuay, 3 km E of Conococha, 10°6'55.5"S, 77°16'20.2"W, 4050 m, 24 Mar 2004, P.M. Peterson & N. Refulio Rodriguez 17939 (MO, US, USM); Recuay. Huascarán National Park, Sector Querococha, above guardstation, 9°44'S, 77°20'W, 3875 m, 5 Jul 1985, D.N. Smith & M. Buddensiek 11045 (CPUN, LPB, MO); Yungay, Huascarán National Park, Llanganuco sector, Maria Josefa trail between Chinancocha and Pucuyacu, 9°5'S, 77°39'W, 3700–3850 m, 7 May 1985, D.N. Smith 10548 (CPUN, MO). Apurimac: Aymaraes, 24 km NE of Chalhuanca on road towards Yanaca, 14°15'26.4"S, 73°12'18.8"W, 4260 m, 13 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16506 (US, USM). Arequipa: Arequipa,10 km W of Patahuasi on road towards Arequipa, 16°4'37.3"S, 71°29'49.8"W, 4100 m, 11 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18243 (MO, US, USM); Arequipa, Jesus−Chiqüata, 2900 m, Jun 1977, C. Vargas C. s.n. (LIL); Arequipa, cerca a Chiquata, 3100 m, 31 Mar 1949, C. Vargas C. 8092 (CUZ, US); Caylloma, 10 km SE of Callalli on road towards Condoroma, 15°29'26"S, 71°23'5.9"W, 4340 m, 12 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18270 (MO, US, USM); Prov. Caylloma, Pampa Cañahuas. “Llapa pasto”, 4200 m, 30 May 2001, M. Rodríguez Diaz 1126 (USM). Ayacucho: Marcahrasi, arriba de Puquio, 3400 m, 24 Apr 1950, R. Ferreyra 7215 (MOL, US, 8USM); Huamanga, S of Ayacucho ca. 23 km on Hwy 3 toward Abancay, 13°16'21.5"S, 74°13'46.8"W, 3575 m, 15 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & D. Susanibar Cruz 20497 (US, USM); Huamanga, S of Ayacucho ca. 27 km on Hwy 3 toward Abancay, 13°17'9.8"S, 74°13'41.9"W, 3684 m, 16 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & D. Susanibar Cruz 20508 (US, USM); Huanca Sancos, 16 km NW of Putajasa on road towards Huanca Sancos, 14°1'42.5"S, 74°16'16.6"W, 3900 m, 25 Feb 2002, P.M. Peterson, A. Cano, M.I. La Torre, A. Ramirez & D. Susanibar Cruz 16254 (US, USM); Lucanas, 13 km E of Puquio at km 172 mark, 14°41'18.5"S, 74°4'26.8"W, 3730 m, 8 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18213 (MO, US, USM); Lucanas, 25 km NE of Villatambo on road towards Lucanas at Reserva “Pampa Galeras”, 14°40'46.2"S, 74°23'59.2"W, 3805 m, 8 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18181 (MO, US, USM); Pampalca, between Huanta and Rio Apurimac, 3200 m, 4 May 1929, E.P. Killip & A.C. Smith 22216 (US). Cajamarca: Cajamarca, S of Cajamarca ca. 9 air km, 7°14'8.1"S, 78°19'17.9"W, 3270 m, 27 Mar 2008, P.M. Peterson, R.J. Soreng, I. Sánchez Vega & J. Montoya Quino 21885 (US, USM); Cajamarca, Cerro Piedras Gachas, entre Yanacocha y Llaucán, 3900 m, 23 Apr 1994, I. Sánchez Vega 6997 & M. Cabanillas S. (CPUN); Cajamarca, entre Cajamarca y Cumbe Mayo, Fundo de la Universidad, 3450 m, 22 May 1971, I. Sánchez Vega 685 & M. Vilhena (CPUN); Cajamarca, entre Cajamarca y Cumbe Mayo, km 14, en el Arboretum Cumbe Mayo CICAFOR, 3400 m, 18 Apr 1981, I. Sánchez Vega 2466, V. Torrel & E. Medina (CPUN); Cajamarca, Dist. Cajamarca. Sais Atahualpa de Porcón en el Arboretum de CICAFOR, 3400 m, 16 May 1981, I. Sánchez Vega 2524, V. Torrel & E. Medina (CPUN); Cajamarca, Dist. Cajamarca, Cerro Gavilán, 3100 m, 26 Jun 1966, I. Sánchez Vega 238 (CPUN); Cajamarca, Dist. Cajamarca, Hacienda Porcón, a 35 km de Cajamarca, 3400 m, 31 May 1969, I. Sánchez Vega 401 (CPUN); Cajamarca, Dist. Cajamarca, Cerro Minas, Granja Porcón, 35 km al N de Cajamarca, 3900 m, 22 Jun 1994, I. Sánchez Vega 7293 & G. Bazan H. (CPUN); Cajamarca. Dist. Cajamarca, Tamiacocha, Cerro Negro, Gavilán, distancia 5 km en línea recta, queda a la vertiente occidental, 7°15'S, 78°28'W, 3558 m, 26 May 2001, I. Sánchez Vega 10618 (CPUN); Cajamarca, ladera que coverge a la Colpa, 2900 m, 22 Apr 1975, I. Sánchez Vega 1419, P. Brandelard, J. Sanabria & W. Ruiz Vigo (CPUN); Cajamarca, Corisorgona, al Norte de la ciudad de Cajamarca, carretera a Chamis, 3050 m, 25 Apr 1991, I. Sánchez Vega 5585 & A. Briones (CPUN); San Miguel, 61 km N of Cajamarca on hwy 3N towards Bambamarca, 3640 m, 16 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14913 (CPUN, MO, US, USM). Cusco: Prov. Calea, Uchumuca−Pisae, Apr 1994, F. Marin 386 (LIL); Calca, 20 km N of Calca on road towards Lares, 13°13'52.9"S, 71°54'26.5"W, 4060 m, 16 Mar 2002, P.M. Peterson & N. Refulio Rodriguez 16546 (US, USM); Prov. Canchis, temple of Viracocha near Tinta, 3500 m, 15 Apr 1913, O.F. Cook & G.B. Gilbert 211 (US); Prov. Cusco, Ruinas Sacsahramán, 3500 m, 6 May 1983, S.G. Beck 8366 (LPB, MO); Prov. Cusco, Tambomachay, 3700 m, Apr 1949, F. Marin 1420 (US, LIL); Prov. Cusco, Cusco–Huancar, 3500 m, 18 Jun 1982, Gutte and Miller 9424 (USM); Prov. Espinar, alrrededores de Youri, 3900 m, 26 Mar 1956, C. Vargas C. 11210, 11211 (CUZ, US); Prov. Espinar, Hacienda C’uyo, 4200 m, 24 Mar 1956, C. Vargas C. 11180 (CUZ, US); Prov. Espinar, Hacienda C’achachi, 4200 m, 20 Mar 1956, C. Vargas C. 11151, 11163 (CUZ, US); Prov. Paucartambo, 1936, J. Soukup s.n. (US); Prov. Paucartambo, Acjanacu, 3600 m, 6 Jul 1948, C. Vargas C. 7299 (CUZ, US); Prov. Paucartambo, Yanamayo, 9 Jul 1946, C. Vargas C. 609 (CUZ, US); Quispicanchi, 23 km up new hwy 28 from Urcos to Ccatcca (Catsa), ESE of Cusco ca. 45 air km, 13°39'39"S, 71°35'29.7"W, 4080 m, 19 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romashchenko 20563 (MO, US, USM); Prov. Urubamba, quebrada Pumahuanca, 3200 m, 31 Dec 1962, H.H. Iltis & C.M. Iltis 1014 (LIL). Huancavelica: Castrovirreyna, 4 km S of Choclococha and 8 km N of Santa Ines, 13°10'44"S, 75°5'15.3"W, 4615 m, 5 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18147 (MO, US, USM); Huancavelica, Huancavelica, 4000 m, 8 Apr 1961, O. Tovar 3171 (MO, USM); Huancavelica, 56 km S of Izacuchaca on road towards Huancavelica, 4020 m, 10 Apr 1997, P.M. Peterson & O. Tovar 14160 (MO, US, USM); Huancavelica, 12 km S of Huancavelica on road towards Santa Barbara, 4120 m, 11 Apr 1997, P.M. Peterson & O. Tovar 14189 (MO, US, USM); Huancavelica, Sachahuajta, a 6 km de Conaica, 3600 m, 3 Apr 1952, O. Tovar 944 (US, USM); Huancavelica, Huando, 3600 m, 6 Apr 1953, O. Tovar 1277 (US, USM); Huancavelica, Canyon of Rio Ichu, SW of Huancavelica ca. 5 km on hwy 3 to Santa Ines and Ayacucho, 12°48'48.2"S, 75°3'24.5"W, 4894 m, 14 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & D. Susanibar Cruz 20464 (MO, US, USM); Huaytara, along Rio Pampas, along hwy 3 (old 24), 12 km NW of jct with new hwy 24 and 18 km SE of Santa Ines, SE of Pilpichaca, 13°19'24.2"S, 75°0'56.6"W, 4164 m, 13 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & D. Susanibar Cruz 20438 (US, USM); Huaytara, 7 km W of Pilpichaca on road towards Huancavelica. 13°18'46.5"S, 75°2'7"W, 4250 m, 5 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18157 (MO, US, USM); Tayacaja, just above Chuquitambo, 4 km SW of Pazos, 3975 m, 9 Apr 1997, P.M. Peterson & O. Tovar 14150 (MO, US, USM); Tayacaja, arriba de Hacienda Tocos, entre Colcabamba y Paucarbamba, 3700 m, 20 Apr 1954, O. Tovar 1961, 2013 (US, USM); Tayacaja, Hacienda Huari, 3700 m, 10 Aug 1949, O. Velarde Nuñez 2038 (US, USM). Huanuco: 18 mi SE of Huanuco, 31 May 1922, J.F. Macbride & W. Featherstone 2114 (F, US); Junín: Prov. Cerro, Goyllarisquisca, 4100 m, 22 Jun 1940, E. Asplund (US); Prov. Huancayo, Acopalca, 3800 m, 20 Jul 1943, J. Infantes Vera 412 (LIL); Prov. Concepción, Cani, 7 mi NE of Mito, 2800 m, 16 Apr 1923, J.F. Macbride 3401 (F, US); Prov. Huancayo, Laive, 3600 m, 15 Mar 1947, J. Infantes Vera 920 (LIL); Prov. Jaupa, 6 km a Concepción, quebrada de Iscos, 3300 m, Mar 1947, C. Ochoa 81 (LIL, MOL, USM); Prov. Yauli, La Oroya, 3950 m, 27 May 1922, J.F. Macbride & W. Featherstone 984 (F, US); Prov. Yauli, Yauli, 4450 m, 25 May 1922, J.F. Macbride & W. Featherstone 916 (F, US). La Libertad: Prov. Otuzco, Purrupumpa, 3585 m, 15 May 1991, S. Leiva, P. Leiva & E. Zavaleta 273 (HAO); Prov. Stgo. Chuco, Cerro La Botica, arriba de Cachicadán, 3050 m, 10 Jun 2001, A. Sagastegui, S. Leiva & M. Zapata 16685 (HAO). Lambayeque: Ferrenafe, 3300 m, 29 Jun 1996, S. Llatas Quiroz 4121 (MO). Lima: arriba de Sucro, 3000 m, 1 May 1948, R. Ferreyra 3445 (MOL, US, USM); Prov. Huarochiri, Matucana, 13 Apr 1922, J.F. Macbride & W. Featherstone 450 (F, US). Moquegua: Carumas, 3200 m, 21 Feb 1925, A. Weberbauer 7295 (US); 1 km S of Puentes Vizcachas, 32 km NE of Humajalso and 18 km S of Titiri, 16°37'14.8"S, 70°24'50.2"W, 4310 m, 18 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18317 (MO, US, USM). Pasco: Pasco, 4 km NE of Huayllay on road towards Canchacucho at “Bosque de Piedras”, 10°58'20.8"S, 76°19'18"W, 4160 m, 31 Mar 2004, P.M. Peterson & N. Refulio Rodriguez 18068 (MO, US, USM). Piura: Huancabamba, abajo del Tabo, 3 Jul 1961, C. Acleto 313 (USM). Puno: Araranca, 4100 m, 21 Apr 1925, F.W. Pennell 13466 (US); W of Llave, 3900 m, 21 Jul 1946, O.P. Pearson & A. Pearson 8 (US); Prov. Carabaya, Ockopuno, 4800 m, Apr 1949, C. Vargas C. 8142 (CUZ, MO, US); Cerro Orco Pata, 4000 m, 17 Jan 1964, R.A. Arevalo 27 (LIL); Prov. Carabaya, Fauchinta Allinccapac, 4600 m, 1 Apr 1948, C. Vargas C. 7157 (CUZ, US); Provincia Lampa, distrito Pucará, inmediaciones del pueblo de Chijnaya, en sustratos arenoso-rocosos en los bordes de la carretera, 4000 m, 14 Jul 2013, D. Giraldo-Cañas 5532 (COL); Pucará, lugar Chijnaya, 3990 m, Mar 1964, A. Vera 108 (COL); Hacienda Iriapata, estación Pucará, 3990 m, Oct 1963, A. Vera s.n. (COL); Chuquibambilla, 3900 m, 19 Apr 1925, F.W. Pennell 13375-1 (US); Chucuito, 2 km S of Huacullani, 4000 m, 6 Mar 1999, P.M. Peterson, N. Refulio Rodriguez & F. Salvador Perez 14660 (MO, US, USM); Chucuito, 5 km S of Huacullani on road towards Kelluyo, 4250 m, 6 Mar 1999, P.M. Peterson, N. Refulio Rodriguez & F. Salvador Perez 14679 (MO, US, USM); Chucuito, 27 km NW of San Jose Ancomarca, 4280 m, 8 Mar 1999, P.M. Peterson, N. Refulio Rodriguez & F. Salvador Perez 14702 (MO, US, USM); El Collao, 34 km E of El Cruce and 24 km W of Mazo Cruz, 4180 m, 2 Mar 1999, P.M. Peterson, N. Refulio Rodriguez & F. Salvador Perez 14595 (MO, US, USM); Lampa, NW end of Laguna Lagunillas, 20 air km W of Santa Lucia, 74 air km WSW of Juliaca, 15°41'1.7"S, 70°48'5.4"W, 4185 m, 31 Mar 2007, P.M. Peterson, R.J. Soreng, K. Romashchenko & M.S. Gonzalez Elizondo 20738 (US, USM); Prov. Lampa, Pucará, A. Weberbauer 415 (US); Melgar, ca. 7 km WNW of Santa Rosa on hwy 3 and 1 km W towards Quishuara, along Rio Santa Rosa, 14°35'54.9"S, 70°51'34.7"W, 4002 m, 23 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romashchenko 20604 (MO, US, USM); Puno, 2 km N of Laraquerion on road towards Puno, 16°6'59.1"S, 70°1'59.1"W, 3940 m, 18 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18329 (MO, US, USM); San Roman, 4 km E of Santa Lucia, along Rio Cabanillas, 15°41'4.2"S, 70°34'8.8"W, 4030 m, 19 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18334 (MO, US, USM); San Roman, 21 km W of Santa Lucia and 5 km E of Puente Cañuma (Laguna Lagunillas), 15°40'4.1"S, 70°47'4.4"W, 4260 m, 20 Apr 2004, P.M. Peterson & N. Refulio Rodriguez 18341 (MO, US, USM).

Muhlenbergia phalaroides (Kunth) P.M. Peterson, Caldasia 31(2): 294–296, f. 7 A–B. 2009.

Fig. 11E, F

Lycurus phalaroides Kunth, Nov. Gen. Sp. (quarto ed.) 1: 142. 1815 (1816). Type: Mexico, Michoacán, near Valladolid, Alberca de Palangeo and Patzcuaro, Sep, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P-00669405 [image!]; isotypes: B-W-1630, BM!, BAA-1530!, US-91988 fragm. ex P-BONPL!, US-610837 fragm. ex LE-TRIN!).

Muhlenbergia lycuroides Vasey ex Beal, Grass. N. Amer. 2: 239. 1896. Type: Mexico, Jalisco, Guadalajara, Jul−Oct 1886, E. Palmer 489 (holotype: MSC; isotypes: GH-00023916 [image!], LE, MEXU, MO-2972929!, NDG-07247 [image!], NY, P-00644181 [image!], P-00644182 [image!], S14-29628 [image!], US-822925!, US-81642!, YU-000898 [image!]).

Lycurus phleoides var. brevifolius Scribn. ex Beal, Grass. N. Amer. 2: 271. 1896. Type: Mexico, Jalisco, plains of Guadalajara, 23 Oct 1889, C.G. Pringle 2470 (lectotype: MSC, designated by C. Reeder, Phytologia 57(4): 288. 1985; isolectotypes: BAA!, GH, MEXU, MO-2972926!, NY!, P-00644183 [image!], P-00644184 [image!], US-996049!, W-18900000580 [image!], W-19160029092 [image!]).

Description

Perennials, intricately branched near base. Culms 10−30 cm tall, erect, mostly glabrous, usually decumbent and sprawling below, bent at the pubescent to short pilose nodes; internodes 0.4−10 (−15) cm long, pubescent to short pilose. Leaf sheaths much shorter than the internodes above, hyaline near the margins, pilose near summit; ligules 0.4−1 mm long, membranous, apex truncate to deltoid, often erose and lacerate; blades 0.5−6.5 cm long, 0.5−1.2 mm wide, shorter near the base of culms, flat, folded or loosely involute, lanate above and glabrous or with scattered, short appressed hairs below, margins whitish-thickened, apex navicular, occasionally with a short seta, seta usually less than 2 mm long. Panicles 1.5−6.5 cm long, 3−8 mm wide, spiciform and spike-like, densely flowered, often interrupted below with only a few spikelets, terminal or axillary; rachis lanate to hispid, the short hairs antrose or appressed; branches 1.5−7 mm long, very short, the spiklets usually in pairs, rarely 1 or 3 per terminal branch, when in pairs the lower short-pedicelled spikelet perfect, staminate or sterile and the upper longer-pedicelled spikelet usually perfect; pedicels 0.3−1.4 mm long; disarticulation usually at the base of the pedicel, each spikelet falling as a unit leaving a small cup-like tip. Spikelets 3−4 mm long, stramineous with plumbeous mottles, sometimes additionally with purplish mottles; glumes 1−2.1 mm long, shorter than the lemma, subequal, 1−3-veined; lower glumes commonly 2 or 3-veined, usually 2-awned, ocassionally 1 or 3 awned, the awns 1−3 mm long, equal or subequal, scabrous, recurved; upper glumes commonly 1-veined, usually 1-awned, the awns 1−2.5 mm long; lemmas 3−4 mm long, narrowly lanceolate, 3-veined, margins hirsute to lanate and occasionally the lower ½ sparsely hairy, the hairs 0.1−0.3 mm long, apex usually awned, occasionally unawned or mucronate, the awns 1−3 mm long; paleas 2.8−3.8 mm long, hairy between the veins, the veins occasionally extending as mucros; anthers 1.3−2 mm long, yellowish. Caryopses 1.7−2 mm long, fusiform, brownish.

Distribution

Muhlenbergia phalaroides ranges from Mexico to South America where it is found in Argentina, Bolivia, Columbia, Ecuador and Peru (Reeder 1985; Sánchez and Rúgolo de Agrasar 1986; Davidse and Pohl 1994).

Ecology

This species occurs in open grasslands and savannahs on steep rocky slopes flats and along disturbed irrigation canals in deep clayish-loam to sandy soils associated with Baccharis, Berberis, Cheilanthes, Condalia, Dodonaea viscosa, Eragrostis, Jarava ichu Opuntia, Muhlenbergia cenchroides, M. rigida, Nassella, Plantago, Puya and Sporobolus indicus (L.) R. Br.; 2800−3500 m.

Comments

Muhlenbergia phalaroides is morphologically similar to M. phleoides (Kunth) Columbus, known in south-western U.S.A. and Mexico and M. alopecuroides found in south-western U.S.A., Mexico and disjunct in Argentina and Bolivia (Davidse and Pohl 1994, Renvoize 1998, Reeder 2003; Peterson and Giraldo-Cañas 2012). Muhlenbergia alopecuroides differs from M. phalaroides in having leaf blades with terminal seta (3−)4−7(−12) mm long and ligules(2−)3−12 mm long whereas M. phleoides differs in having auriculate ligules 1−2 mm long (Reeder 1985, 2003). These morphological differences are perhaps better recognised at the subspecific level but there have been no population studies comparing these three species, other than Peterson and Morrone (1997) who investigated populations of only the amphitropical, M. alocpecuroides [as Lycurus setosus].

Muhlenbergia phalaroides lies within M. subg. Pseudosporobolus, aligning with M. alopecuroides and M. phleoides (Peterson and Romaschenko, in prep.). Many members of this subgenus have narrow panicles, plumbeous spikelets with unawned, mucronate or short-awned lemmas (Peterson et al. 2010b).

Specimens examined

Peru. Ancash: 15 Mar 1947, J. Infantes Vera 1170 (LIL). Ayacucho: Huanca Sancos, 27 km NW of Putajasa and 3 km S of Sacsamarca, 13°57'51.1"S, 74°18'41.5"W, 3650 m, 25 Feb 2002, P.M. Peterson 16277, A.A. Cano, M.I. LaTorre, A. Ramirez & D. Susanibar (US, USM). Cusco: Canchis, Hacienda Occobamba, 3450 m, 4 Apr 1950, C. Vargas C. 9410 (CUZ, US); Prov. Quispicanchis, Pikillacta, 3250 m, 28 Apr 1946, C. Vargas C. 6033 (CUZ, US). Huancavelica: near Huancayo, 3270 m, 1 Apr 1952, O. Tovar 344 (US, USM); Sacxhahuajta, a 6 km de Conaica, 3600 m, 3 Apr 1952, O. Tovar 939 (US, USM). Junín: Huancayo, 3317 m, Mar 1943, J. Soukup 1900 (COL, LIL, US); Prov. Huancayo, Agua de las Virgenes, 3270 m, 1 Apr 1951, O. Tovar 344 (MOL, USM); Tarma, between La Oroya and La Merced, 3000 m, 24 Oct 1923, A.S. Hitchcock 22169 (US).

Muhlenbergia rigida (Kunth) Kunth, Révis. Gramin. 1: 63. 1829.

Fig. 6D−F

Podosemum rigidum Kunth, Nov. Gen. Sp. (quarto ed.) 1: 129. 1816. Trichochloa rigida (Kunth) Roem. & Schult., Syst. Veg. 2: 386. 1817. Agrostis rigida (Kunth) Spreng., Syst. Veg. 1: 262. 1825. Type: Mexico, Guanajuato, near Guanajuato, Sep, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P!; isotypes: BAA!, US-91920 fragm. ex P!).

Podosemum elegans Kunth, Nov. Gen. Sp. (quarto ed.) 1: 130. 1816. Trichochloa elegans (Kunth) Roem. & Schult., Syst. Veg. 2: 387. 1817. Agrostis quitensis Spreng., Syst. Veg. 1: 262. 1825. Type: Ecuador, Chimborazo, Paramo de las Puntas & Pomallacta, Jun, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P!; isotype: BAA!).

Podosemum glabratum Kunth, Nov. Gen. Sp. (quarto ed.) 1: 130. 1816. Trichochloa glabrata (Kunth) Roem. & Schult., Syst. Veg. 2: 387. 1817. Agrostis glabrata (Kunth) Spreng., Syst. Veg. 1: 262. 1825. Type: Mexico, Santa Rosa de la Sierra and Cañada de Acabuca, Sep, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P-Bonpl!; isotype: US-91921 fragm. ex P-Bonpl!).

Muhlenbergia berlandieri Trin., Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 6,4(3–4): 299. 1841. Type: Mexico, Distrito Federal, Mountains near México, Aug 1827, J.L. Berlandier 676, 684 (lectotype, designated here: LE-TRIN-1487.01!, both collection numbers appear on the label with a single specimen and figure); México, 26 Aug 1827, J.L. Berlandier 676 (isolectotypes: COL-000006382 [image!]; P-00644117 [image!], P-00644119 [image!], US-2557457!, US-87241 fragm!, W-239604!, W-0029177 [image!]).

Muhlenbergia affinis Trin., Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 6,4(3–4): 301. 1841. Podosemum affine (Trin.) Bush, Amer. Midl. Naturalist 7(2):40. 1921. Type: Mexico, México, Toluca, J.L. Berlandier 1083 (lectotype, designated here: P-00644141 [image!]; isolectotypes: G-00099411 [image!], G-00099410 [image!], G-00099409 [image!], LE-TRIN-1485.01 fragm.!, P-00644142 [image!], US-87237 fragm.!).

Muhlenbergia phragmitoides Griseb., Abh. Königl. Ges. Wiss. Göttingen 19: 255. 1874. Type: Argentina, Tucumán: Cuesta de Anfama, Sierra de Tucumán, 23 Mar 1872, P.G. Lorentz 79 (lectotype, designated here: GOET-006649 [image!]; isolectotypes: BAA-00002225 [image!], CORD-00004622 [image!], GOET-006648 [image!], SI-002780 [image!], US-91911 fragm. ex GOET!).

Muhlenbergia elegans var. atroviolacea Kuntze, Revis. Gen. Pl. 3(3): 357. 1898. Type: Bolivia, Cochabamba, 3000 m, 26 Mar 1892, O. Kuntze s.n. (lectotype, designated here: NY-00381485 [image!].

Muhlenbergia elegans var. subviridis Kuntze, Revis. Gen. Pl. 3(3): 357. 1898. Type: Bolivia, Tunari Mts, 1600 m, O. Kuntze (lectotype, designated here: NY-00381486 [image!]).

Muhlenbergia metcalfei M.E. Jones, Contr. W. Bot. 14: 12. 1912. Type: U.S.A. New Mexico: Grant Co., Santa Rita Mountains, in and around S end of the Black Range, 7000 ft alt., 9 Oct 1904, O.B. Metcalf 1485 (holotype: POM-116640!; isotypes: GH-00023980 [image!], MO!, US!).

Muhlenbergia holwayorum Hitchc., Contr. U.S. Natl. Herb. 24(8): 389. 1927. Type: Bolivia, Sorata, 16 Apr 1920, E.W.D. Holway & M.M. Holway 530 (holotype: US-1108445!).

Description

Densely caespitose perennials. Culms 40–100 cm tall, stiffly erect, glabrous to scaberulous below the basal, terete nodes, usually 1 node per culm; internodes mostly glabrous. Leaf sheaths 2–30 cm long, longer than the internodes, glabrous to scaberulous, rounded near base; ligules (1–)3–6(−8) mm long, often lacerate, firmer below, strongly decurrent, apex obtuse to acute; blades 12–35 cm long, 1–3 mm wide, flat or involute, glabrous to scaberulous below and scaberulous to hirsutulous above. Panicles (4–)10–35 cm long, (2–)3–5(–15) cm wide, loosely contracted to open and lax, reddish-purple; primary branches 0.4–10 cm long, sometimes capillary, ascending and spreading up to 80° from the rachises; pedicels 1–10 mm long, mostly longer than the spikelets. Spikelets 3.5–5 mm long, reddish-purple; glumes 1–1.7(–2) mm long, much shorter than the floret, about equal, 1-nerved, unawned, apex obtuse to subacute, sometimes hirsutulous, rarely mucronate; lemmas 3.5–5 mm long, narrow lanceolate, scaberulous to scabrous, purple, awned, callus with hairs up to 0.5 mm long, apex acuminate, the awns (8–)10–22 mm long, flexuous; paleas 3.5–5 mm long, narrow lanceolate, purple, scaberulous, apex acuminate; anthers 1.7–2.3 mm long, reddish-purple. Caryopses 2–3.5 mm long, fusiform, brownish. 2n = 40, 44.

Distribution

Muhlenbergia rigida ranges from Arizona, New Mexico and south-western Texas, throughout México and Central America to South America where it occurs along the Andes from Columbia, Venezuela, Ecuador, Bolivia, Peru and Argentina.

Ecology

This species occurs on rocky slopes, ravines and sandy, gravelly slopes derived from granitic and calcareous substrates associated with Acacia, Agave, Aristida, A. adscensionis, Baccharis, Berberis, Bidens, Bouteloua curtipendula (Michx.) Torr., Caesalpinia, Calamagrostis, Colletia spinosissima, Cortaderia bifida, C. jubata, Desmodium, Dodonaea viscosa, Ephedra, Eragrostis, Eupatorium, Festuca, Fucaria, Hypericum, Jarava, Krameria, Lepechinia, Lupinus, Lycium, Melinus minutiflora, Mirabilis, Opuntia, Paspalum, Cenchrus clandestinus, Peperomia, Puya, Salvia, Schinus molle, Schizachyrium, Sporobolus, Tillandsia and Trichocereus; 2000–3650 m.

Comments

This species is highly variable and is one of the most common upland bunchgrasses forming almost pure stands in northern México, less common in Peru and South America where it is usually found in smaller populations. Muhlenbergia rigida can be distinguished morphologically from M. coerulea and M. coerulea × rigida in having shorter lemmas 3.5−5 mm long with long flexuous awns (8–)10–22 mm long and shorter glumes 1–1.7(–2) mm long.

Molecular DNA sequence analysis indicates M. rigida lies within Muhlenbergia subg. Trichochloa and genetically is highly variable (Fig. 1A; Peterson et al. 2010b).

Specimens examined

Peru. Amazonas: 66 km from Leymebamba towards Balsas, S.A. Renvoize & S. Lægaard 4934 (CPUN); Prov. Chachapoyas, Cerro Puma Urco S of Chachapoyas, C.P. Cowen 4308, J. Canne & V. Torrel (USM). Ancash: E of Yungay, S.A. Renvoize & S. Lægaard 5053 (CPUN); 10 km from Huaraz towards Casma, S.A. Renvoize & S. Lægaard 5153 (CPUN); Prov. Bolognesi, Tanás, E. Cerrate 1381 (US, USM); Aynín, E. Cerrate 1341 (USM); Casca, below Chiquián, R. Ferreyra 7285 (US, USM); above Chiquián, E. Cerrate 372, 480 (US, USM); Shapash, near Chiquián, F. Ferreyra 5696 (US); Yungay, Prov. Huaraz, 23 Apr 1995, S. Llatas Quiroz 3630 & J. Campos de la Cruz (USM); Prov. Huaraz, W side of Cordillera Blanca, S of quebrada Ishinca, 9°24'55.8"S, 77°32'45.8"W, 2885 m, 12 Mar 2008, P.M. Peterson 21610, R.J. Soreng, M. La Torre & J.V. Rojas Fox (US, USM); Corongo, N end of Cordillera Blanca, 12 km W of Tarica towards Yuacmarca, 8°35'55.6"S, 77°50'4.8"W, 2849 m, 18 Mar 2008, P.M. Peterson 21782 & R.J. Soreng (US, USM); Cordillera Negra E slope, S side of quebrada W of Shupluy, 9°13'30.0"S, 77°42'6.6"W, 2476 m, 13 Mar 2008, P.M. Peterson 21628, R.J. Soreng, M. La Torre & J.V. Rojas Fox (US, USM); Prov. Huaraz-Recuay border, W side of Rio Santa Canyon, 9°40'58.1"S, 77°28'29.7"W, 3202 m, 11 Mar 2008, P.M. Peterson 21605, R.J. Soreng, M. La Torre & J.V. Rojas Fox (US, USM); Prov. Huari, Cordillera Blanca, 21 km S of Huari on road towards San Marcos, 2850 m, 22 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13862 (US, USM); Uco near Rio Puchca, A. Cano 14317, M.I. La Torre, W. Mendoza & C. Mendoza (USM); San Marcos, A. Cano 13395, W. Mendoza, I. Salinas & A. Ramirez (USM); Prov. Huaylas, below Huaylas, E. Carrillo 1297, W. Medina & P. Huamán (USM); Pueblo Libre, A. Cano 11616 (USM); Prov. Pallasca, 3.4 km N of Huandoval towards Huascaschuque and Pallasca, 8°18'59.2"S, 77°58'9.5"W, 2949 m, 21 Mar 2008, P.M. Peterson & R.J. Soreng 21818 (US, USM); divide between Rio Conchucos and Rio Plata, 8°12'9.1"S, 77°56'20.6"W, 2233 m, 21 Mar 2008, P.M. Peterson & R.J. Soreng 21834 (US, USM); Prov. Recuay, Catac, L.I. Masias 47 (USM); Prov. Yungay, Cordillera Negra, 18 km SW of Shuplay and Rio Santa, 9°14'52.7"S, 77°43'44.1"W, 2901 m, 13 Mar 2008, P.M. Peterson 21637, R.J. Soreng, M. La Torre & J.V. Rojas Fox (US, USM); Cordillera Blanca W slope, 5 km E of Yungay, below Shillcop, 9°9'11.7"S, 77°43'27.6"W, 2597 m, 15 Mar 2008, P.M. Peterson 21687, R.J. Soreng, M. La Torre & J.V. Rojas Fox (US, USM); Kuisho, M. La Torre 419 (USM); Shupluy, A. Cano 11354 (USM); Shilco, E. Cerrate 7753 (USM). Apurimac: Prov. Grau, Cotobambas−Cochapata, C. Vargas C. 5789 (US). Ayacucho: A. Weberbauer 5525 (US); Prov. Lucanas, Quebrada Chuela, 3 Apr 1942, R.D. Metcalf 30315 (LIL); Prov. Huamanga, Quellagocha, 4000 m, 5 Apr 1967, V. Palomino 242 (USM); Prov. Huamanga, 4 km S of Ayacucho on hwy 3 towards Abancay, 13°11'33.8"S, 74°12'2.1"W, 2952 m, 15 Mar 2007, P.M. Peterson 20475, R.J. Soreng, K. Romaschenko & D. Susanibar Cruz (US, USM); 21 km S of Ayacucho on hwy 3 towards Abancay, 13°16'21.5"S, 74°13'46.8"W, 3575 m, 15 Mar 2007, P.M. Peterson 20487, R.J. Soreng, K. Romaschenko & D. Susanibar Cruz (US, USM); Cerro Acuchimay above Ayacucho, O. Tovar 5399 (USM); Huatalás, V. Palomino 34 (USM); Prov. Huanca Sancos, 27 km NW of Putajasa and 3 km S of Sacsamarca, 13°57'51.1"S, 74°18'41.5"W, 3650 m, 25 Feb 2002, P.M. Peterson 16273A, A. Cano, M. La Torre, A Ramirez & D. Susanibar (US, USM); Prov. Huata, Rio Cachi below Huanta, O. Tovar 4946 (US, USM); Prov. Lucanas, near Puquio, R. Ferreyra 7187 (MOL,US, USM); vicinity of Puquio, O. Tovar 9 (USM). Cajamarca: near side road to Chugur, 95 km from Cajamarca, S.A. Renvoize 4847, S. Lægaard & I. Sánchez Vega (CPUN); above Celendín, S.A. Renvoize & S. Lægaard 4877 (CPUN); Prov. Cajabamba, 14 km WSW of Cajabamba, E of Araqueda, 7°39'9.1"S, 78°9'58.9"W, 2242 m, 23 Mar 2008, P.M. Peterson & R.J. Soreng 21854 (US, USM); Prov. Cajamarca, 6 km NW of San Marcos on road towards Cajamarca, 2570 m, 30 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 14009 (US, USM); 1 km S of Huambocancha on road towards Cajamarca, 2770 m, 14 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 14853 (CPUN, US, USM); Parque forestall Aylambo, 4 km de Cajamarca, I. Sánchez Vega 987 (CPUN); 4 km S of Jesús, I. Sánchez Vega 2376 (CPUN); Tres Molinos, T. Tejada 46 (CPUN); S of Paso El Gavelán, 10 air km S of Cajamarca, 7°15'37.2"S, 78°30'34.5"W, 2544 m, 26 Mar 2008, P.M. Peterson 21878, R.J. Soreng & I. Sánchez Vega (US, USM); near Gavilán and San Juan, I. Sánchez Vega & W. Ruiz Vigo 650 (CPUN); bajando Paso El Gavilán a San Juan, I. Sánchez Vega & W. Ruiz Vigo (CPUN); near Paso El Gavilán, I. Sánchez Vega 1400, P. Brandelard & J. Sanabria (CPUN); bajadas de Chancay a Valle de Condebamba, I. Sánchez Vega 1112 (CPUN); above San Pablo, I. Sánchez Vega 1495 (CPUN); near Jesús, I. Sánchez Vega 1066 (CPUN); S of Jesús Tabada, I. Sánchez Vega 2376 (CPUN, US); between Cajamarca and Celendín, R. Ferreyra 15004 (USM); 20 km from Celendín, P. Gutti & G. Müller s.n. (USM); Chotén, 4 km de la carretera Pacasmayo, I. Sánchez Vega 2569, V. Torrel & E. Medina (CPUN); Bellavista, I. Sánchez Vega 1842, W. Ruiz Vigo & J. Sánchez Vega (CPUN); Chotén Bajo, J. Cabanillas S. & J. Guevara B. 665 (CPUN); Cerro Rumicucho, km 11 de la carretera Cajamarca Cajabamba, I. Sánchez Vega 2492, V. Torrel & E. Medina (CPUN); near Chancay and Valle de Condebamba, I. Sánchez Vega 2412, V. Torrel & E. Medina (CPUN); Cerro Huacarís, Valle de Cajamarca, I. Sánchez Vega 444 (CPUN); Prov. Celendín, above Limon, 27 km E of Celendín, 6°53'15.2"S, 78°5'30.5"W, 2215 m, 29 Mar 2008, P.M. Peterson 21927, R.J. Soreng & J. Montoya Quino (US, USM); Marañón river Valley, Chachapoyas−Cajamarca road, D.N. Smith & J. Cabanillas 7272 (MO, US); Prov. Chota, 5 km de Cochabamba a Cutervo, I. Sánchez Vega 4845 (CPUN); 6 km de Cochabamba, I. Sánchez Vega 2334 (CPUN); Prov. Contumaza, Hacienda San Lorenzo, San Benito, A. Sagástegui 3784 (US), Cerro Campanillas, A. Sagástegui 2992 (US); Shamon, A. Sagástegui 14305 (HAO); Prov. Cutervo, 13 km W of Cutervo on road towards Socoto, 2160 m, 20 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 15008 (CPUN, US, USM). Cusco: 2 km S of San Jeronimo and 10 km SE of Cusco, J.C. Soloman 2985 (USM); Prov. Anta, Mollepata, C. Vargas C. 19049 (USM); Prov. Calea, Pisai, F. Marin 512a (LIL); Prov. Cusco, Cusco−Huancar, P. Gutti & G. Müller 94269b (USM); Prov. Urubamba, Cerro Chicón, P. Nuñez V. 8895 (MO, US); Chincheros, just below Perga Kachun, S. King 316, E. Franquemont, C. Franquemont & C. Sperling (USM); lower end of quebrada Pumahuanca, H.H. Iltis 855, C.M. Iltis & C. Vargas C. (LIL, USM); Machu Pichu, I. Grignon 2305 (US); ESE of Cusco, H. Ellenberg 1018 (US); Prov. Yaurisque, Paruro, SW of Cusco, P. Nuñez 7383 (USM). Huancavelica: Prov. Huancavelica, Mariscal Cáceres, O. Tovar 1405 (US, USM); Prov. Tayacaja, near Huachocolpa, O. Tovar (US, USM); near Surcubamba, O. Tovar 4240 (US, USM); Mejorada, O. Tovar 2454 (US, USM); Mamacha-rumi, O. Tovar 2439 (US, USM); Prov. Taycaya, Valle del Rio Mantero, A. Weberbauer 6448 (MOL). Huánuco: Prov. Ambo, above Hacienda Quicacán, near Huánuco and Ambo, R. Ferreyra 9228 (US, USM); Huarmiragra, A. Granda Paucar 1791 (USM); Prov. Huánuco, 7 km S of Ambo on hwy 3 towards Cerro de Pasco, 10°11'49"S, 76°9'54"W, 2345 m, 6 Mar 2007, P.M. Peterson 20322, R.J. Soreng & K. Romaschenko (US, USM); Cerro San Cristobal, P. Aguilar 808 (USM); Prov. Pachitea, 21 air km NE of Huánuco, 7 km E of Puerto Rancho junction, 9°49'45.9"S, 76°3'12.9"W, 2094 m, 6 Mar 2007, P.M. Peterson 20334, R.J. Soreng & K. Romaschenko (US, USM). Junín: Chorrillos, B. Maass 487 (USM); Prov. Huancayo, near Huancayo, O. Tovar 2747 (US, USM); Prov. Huancayo, Acopalca, 20 Jan 1952, J. Infantes Vera 1586 (LIL); Huancayo, 3317 m, Mar 1943, J. Soukup 1899 (COL, US); Montaro Valley W of Huancayo, 3800 m, 14 Jul 1982, S.A. Renvoize 4328 (USM); below Pariahuana, O. Tovar 7899, 7944 (USM); Prov. Tarma, 1 km up road to Hacienda Maraynioc out of Palca, 2800 m, 6 Apr 1997, P.M. Peterson & O. Tovar 14055 (US, USM); Tarma, E.P. Killip & A.C. Smith 21802 (US); A.S. Hitchcock 22165 (US). La Libertad: Usquil, E. Anderson 1293 (US); Prov. Bolivar, 0.5 km W of Longotea towards San Vicente, 7°2'35.6"S, 77°52'39.8"W, 2487 m, 31 Mar 2008, P.M. Peterson 21968, R.J. Soreng & J. Montoya Quino (US, USM); 4.6 km NW of Longotea, SE of San Vicente, 7°00'38.0"S, 77°54'15.2"W, 2058 m, 31 Mar 2008, P.M. Peterson 21969, R.J. Soreng & J. Montoya Quino (US, USM); Prov. Huamachuco, Llautobamba, J. Infautes 5509 (US); Prov. Santiago de Chuco, 22 km E of Huamachuco on road towards Sarin, 2500 m, 29 Mar 1997, P.M. Peterson & N. Refulio Rodriguez 13984 (US, USM). Lima: Prov. Huarochiri, Tambo de Viso, J.F. Macbride & Featherstone 765 (F, US); Matucana, J.F. Macbride & Featherstone 358 (F, US). Pasco: 10 km unterhalb Tarma, Ellenberg 8787 (USM). Piura: Prov. Huancabamba, 7 km E of Sondor on road towards Tabaconas, 2200 m, 31 Mar 2000, P.M. Peterson & N. Refulio Rodriguez 15162 (CPUN, US, USM); Abra de Porculla, R. Ferreyra 13734 (US, USM); 11 km Huancabamba−Salalá, I. Sánchez Vega 5160 (CPUN).

Muhlenbergia romaschenkoi P.M. Peterson, sp. nov.

Fig. 12A−L

Type

Peru. Depto. Huánuco, Pachitea, 21 air km NE of Huánuco, 7 km E of Puerto Rancho jtn on road to Panao, along Río Huallaga, 9°49'45.9"S, 76°3'12.9"W, 2094 m, 6 Mar 2007, P.M. Peterson 20331, R.J. Soreng & K. Romaschenko (holotype: US-3730646!; isotypes: MO!, USM!).

Description

Loosely caespitose to densely tufted, annuals to short-lived perennials with delicate bases, flowering the first year. Culms 20–40 cm tall, erect or decumbent at the base, branching at the lower and middle nodes, scaberulous below the terete nodes; internodes generally 2.0–9.5 cm long. Leaf sheaths 4.0–7.5 cm long, glabrous or scaberulous, commonly shorter than the internodes; ligules 1.2–3.0(–5.0) mm long, hyaline, apex acute to obtuse, often lacerate with age; blades 3–12 cm long, 1.2–2.5 mm wide, flat or loosely involute, scaberulous to glabrous below and scabrous above. Panicles 7–15 cm long, 0.6−2 cm wide, narrow and contracted to loosely spreading, interrupted below, terminal and axillary, 15–23 nodes per panicle; primary branches 3.5–7.5 cm long, usually one per node, when immature the branches mostly appressed and ascending, when mature the branches sometimes widely spreading up to 50° from the rachises; pedicels 1–3 mm long, usually shorter than the spikelets, antrorsely scabrous, stout, appressed. Spikelets 2–4 mm long, erect, stramineous to purplish; glumes 1–2.8 mm long, unequal, 1-nerved, scabrous along the nerves, apex acute to acuminate, often mucronate or erose, the mucro up to 0.5 mm long; lower glumes 1–2.0 mm long; upper glumes 1.5–2.8 mm long, more than ½ as long as the lemma; lemmas 2.0–3.5(–4.0) mm long, lanceolate, widest near base, awned, scaberulous above and villous on proximal 1/2 along the margins and the midvein, the hairs 0.5–1.5 mm long, callus short-pubescent, the awn 10–30 mm long, scabrous, flexuous; paleas 1.8–3.4(–3.8) mm long, lanceolate, sparsely appressed pubescent between the nerves on the proximal ½; anthers 0.3−0.4 mm long, purplish, yellow with age. Caryopses 1.0–2.2 mm long, narrowly fusiform, terete, brownish.

Figure 12. 

Muhlenbergia romaschenkoi P.M. Peterson A habit B ligule C spikelet D lower glume E upper glume F lemma, lateral view G lemma, dorsal view H palea, dorsal view I palea, lateral view J palea, ventral view K lodicules, stamens, and pistil L caryopsis. Drawings from the holotype collection P.M. Peterson, R.J. Soreng & K. Romaschenko 20331.

Distribution

Endemic to Peru and known only from Huánuco.

Ecology

Muhlenbergia romaschenkoi grows on rocky slopes and limestone rock outcrops in grasslands with Aristida adscensionis, Bidens, Bothriochloa, Eragrostis nigricans (Kunth) Steud., Eupatorium, Melinus minutiflora, Microchloa kunthii Desv., Muhlenbergia ciliata, M. rigida and Nassella; 1800–2500 m.

Etymology

We honour Dr. Konstantin Romaschenko (born 1969) who accompanied PMP and Robert J. Soreng on the collecting trip in which material of the species was gathered.

Comments

Muhlenbergia romaschenkoi can be separated from M. microsperma in having longer acute to acuminate glumes (1–2.8 mm long) and by lacking cleistogamous panicles present in the axils of the lower sheaths. Muhlenbergia tenuifolia (Kunth) Kunth, a species ranging from southern Arizona, New Mexico and Texas, U.S.A., throughout México and then again in Venezuela, Bolivia and Argentina, is morphologically similar to M. romaschenkoi but differs in having yellowish anthers 0.9−1.5 mm long (Peterson and Annable 1991; Peterson 2003; Peterson et al. 2007b; Peterson and Giraldo-Cañas 2011, 2012). Initially we thought the new species was M. tenuiofolia with immature anthers 0.3−0.4 mm long. However, our collection of M. romaschenkoi includes well-developed florets with mature caryopses and anthers. Therefore, the observed small anthers in M. romaschenkoi are not a result of immaturity but represent a genetic difference, from M. tenuifolia, which is not known in Peru.

Muhlenbergia romaschenkoi, a member of M. subg. Muhlenbergia, is sister to M. spiciformis Trin. (plastid marker), a species known from south-western United States and throughout Mexico whereas ITS marker aligns it within the M. tenuifolia clade (Fig. 1B). Muhlenbergia spiciformis differs from the new species in having shorter glumes 0.3−1 mm long and larger anthers 0.9−1.6 mm long (Peterson 2003; Peterson et al. 2007b). These results suggest multiple origins for M. romaschenkoi from North and South American progenitors. Similar to M. caxamarcenis, this scenario appears to be a common pattern of speciation for South American species of Muhlenbergia, needing further study.

Specimen examined

Peru. Huánuco: between Huánuco and Tingo María, vereda Taruka, 17 km NE of Huánuco in valley of Río Huallaga, T. Croat 57781 (MO).

Infrageneric classification of the species of Muhlenbergia in Peru

Muhlenbergia subg. Bealia (Scribn.) P.M. Peterson: M. caxamarcensis, M. ligularis.

Muhlenbergia subg. Clomena (P. Beauv.) Hack.: M. peruviana.

Muhlenbergia subg. Muhlenbergia: M. beyrichiana, M. bryophilus, M. cenchroides, M. ciliata, M. diversiglumis, M. flexuosa, M. microsperma, M. romaschenkoi.

Muhlenbergia subg. Pseudosporobolus (Parodi) P.M. Peterson: M. fastigiata, M. monandra, M. phalaroides.

Muhlenbergia subg. Trichochloa (P. Beauv.) A. Gray: M. coerulea, M. coerulea × M. rigida, M. maxima, M. rigida.

Species excluded

Muhlenbergia tenuissima (Presl) Kunth, Enum. Pl. 1: 198. 1833.

Discussion

This taxon is a distinctive species which seems to be restricted to chalky limestone flats usually occurring as a dense carpet on clay-like soils in open savannahs; known from North America and Central America (Peterson and Annable 1991; Brako and Zarucchi 1993). Although previously included for Peru in Hitchcock (1927), Standley (1936) and Tovar (1993), the specimens cited are M. ciliata without prominent cilia along the lateral veins (see discussion of M. ciliata).

Muhlenbergia tenuifolia (Kunth) Kunth, Révis. Gramin. 1(4):63. 1829.

Discussion

This taxon was reported for Peru in Brako and Zarucchi (1993) who cited Croat 57781 which we place in M. romaschenkoi.

Acknowledgements

We thank the Smithsonian Institution’s Restricted Endowment Fund, the Scholarly Studies Program, Research Opportunities, Atherton Seidell Foundation, Biodiversity Surveys and Inventories Program, Small Grants; the National Geographic Society for Research and Exploration (Grant No. 8848-10, 8087-06); Alice R. Tangerini, Midge Gillete, Vladimiro Dudás, Susan C. Escher and Cathy Pasquale for preparing the illustrations; and Jeffery M. Saarela and Robert J. Soreng for suggesting improvements to the manuscript.

References

  • Beetle AA (1948) The genus Aegopogon Humb. & Bonpl. University of Wyoming Publications (Laramie, Wyo. ) 13: 17–23.
  • Brako L, Zarucchi JL (1993) Catalogue of the flowering plants and gymnosperms of Peru. Monographs in Systematic Botany from the Missouri Botanical Garden 45: 1–1286.
  • Brown W (1977) The Kranz syndrome and its subtypes in grass systematics. Memoirs of the Torrey Botanical Club 23: 1–97.
  • Davidse G, Pohl RW (1994) 262. Poaceae. In: Davidse G, Sousa SM, Chater AO (Eds) Flora Mesoamericana, Volumen 6, Alismataceae a Cyperaceae. Universidad Nacional Autónoma de Mexico, Instituto de Biología, Mexico, D.F., 184−402.
  • Dengler NG, Dengler RE, Hattersley PW (1986) Comparative bundle sheath and mesophyll differentiation in the leaves of C4 grasses Panicum effusum and P. bulbosum. American Journal of Botany 73(10): 1431–1442. https://doi.org/10.1002/j.1537–2197.1986.tb10889.x
  • Espejo Serna A, López-Ferrari AR, Valdés-Reyna J (2000) Poaceae Barnhart. In: Espejo Serna A, Ferrari L (Eds) Las Monocotiledóneas Mexicanas, una Sinopsis Florística. Consejo Nacional de la Flora de México, Universidad Autónoma Metropolitana-Iztapalapa, and Comisión Nacional para el conocimiento y uso de la Biodiversidad, México, D.F., 7−236.
  • Giraldo-Cañas D, Peterson P (2009) El género Muhlenbergia (Poaceae: Chloridoideae: Cynodonteae: Muhlenbergiinae) en Colombia. Caldasia 31: 269–302.
  • Hattersley PW, Watson L (1976) C4 grasses: An anatomical criterion for distinguishing between NADP-malic enzyne species and PCK or NAD-malic enzyme species. Australian Journal of Botany 24(2): 297–308. https://doi.org/10.1071/BT9760297
  • Hattersley PW, Watson L (1992) Diversification of photsynthesis. In: Chapman GP (Ed.) Grass evolution and domestication. Cambridge University Press, Great Britain, 38−116.
  • Herrera Arrieta Y (1998) A revision of the Muhlenbergia montana (Nutt.) Hitchc. complex (Poaceae: Chloridoideae). Brittonia 50(1): 23–50. https://doi.org/10.2307/2807714
  • Herrera Arrieta Y, Peterson PM (2007) Muhlenbergia (Poaceae) de Chihuahua, México. Sida. Botanical Miscellany 29: 1–109.
  • Herrera Arrieta Y, Peterson PM (2017) Subfamily Chloridoideae, Parte 1 (Muhlenbergia). Flora del Bajío y de Regiones Adyacentes 199: 1–130.
  • Herrera Arrieta Y, Peterson PM (2018) Grasses of Chihuahua, Mexico. Smithsonian Contributions to Botany 107: 1–380.
  • Hitchcock AS (1920) The genera of grasses of the United States. United States Department of Agriculture. Bulletin 772: 1–302.
  • Hitchcock AS (1927) The grasses of Ecuador, Peru, and Bolivia. Contributions from the United States National Herbarium 24: 291–556.
  • Lægaard S, Peterson PM (2001) 214(2). Gramineae (part 2) Subfam. Chloridoideae. In: Harling G, Andersson L (Eds) Botanical Institute, University of Göteborg, Göteborg, 1−131.
  • Morden CW (1985) A biosystematic study of the Muhlenbergia repens complex (Poaceae). PhD. Dissertation. Texas A&M University, College Station.
  • Morden CW, Hatch SL (1984) Cleistogamy in Muhlenbergia cuspidata (Poaceae). Sida 10: 254–255.
  • Morden CW, Hatch SL (1996) Morphological variation and synopsis of the Muhlenbergia repens complex (Poaceae). Sida 17: 349–365.
  • Pelser PB, Kennedy AH, Tepe EJ, Shidler JB, Nordenstam B, Kadereit JW, Watson LE (2010) Patterns and causes of incongruence between plastid and nuclear Senecioneae (Asteraceae) phylogenies. American Journal of Botany 97(5): 856–873. https://doi.org/10.3732/ajb.0900287
  • Peterson PM (2000) Systematics of the Muhlenbergiinae (Chloridoideae: Eragrostideae). In: Jacobs SWL, Everett J (Eds) Grasses: Systematics and Evolution. CSIRO, Melbourne, 195−212.
  • Peterson PM (2003) 17.33 Muhlenbergia Schreb. In: Barkworth ME, Capels KM, Long S, Piep MB (Eds) Magnoliophyta: Commelinidae (in part): Poaceae, part 2 Flora of North America North of Mexico, Vol 25. Oxford University Press, New York, 145−201.
  • Peterson PM, Annable CR (1991) Systematics of the annual species of Muhlenbergia (Poaceae-Eragrostideae). Systematic Botany Monographs 31: 1–109. https://doi.org/10.2307/25027794
  • Peterson PM, Annable CR (1992) A revision of Chaboissaea (Poaceae: Eragrostideae). Madrono 39: 8–30.
  • Peterson PM, Columbus JT (2009) Muhlenbergia tarahumara (Poaceae: Chloridoideae: Cynodonteae: Muhlenbergiinae), a new species from Chihuahua, Mexico. Journal of the Botanical Research Institute of Texas 3: 527–534.
  • Peterson PM, Giraldo-Cañas D (2011) Las especies de Muhlenbergia (Poaceae: Chloridoideae) de Argentina. Caldasia 33: 21–54.
  • Peterson PM, Giraldo-Cañas D (2012) Muhlenbergia Schreb. In: Zuloaga FO, Rugolo ZE, Anton AMR (Eds) Flora Argentina, Flora Vascular de la Republica Argentina, Vol. 3, Tomo 1, Monocotyledoneae, Poaceae: Aristidoideae a Pharoideae. IBODA-IMBIV, CONICET, Buenos Aires, Argentina, 140−154.
  • Peterson PM, Herrera Arrieta Y (2001) A leaf blade anatomical survey of Muhlenbergia (Poaceae: Muhlenbergiinae). Sida 19: 469–506.
  • Peterson PM, Morrone O (1997) Allelic variation in the amphitropical disjunct Lycurus setosus (Poaceae: Muhlenbergiinae). Madrono 44: 334–346.
  • Peterson PM, Webster RD, Valdés-Reyna J (1995) Subtribal classification of the New World Eragrostideae (Poaceae: Chloridoideae). Sida 16: 529–544. https://doi.org/10.5962/bhl.part.3478
  • Peterson PM, Webster RD, Valdes Reyna J (1997) Genera of New World Eragrostideae (Poaceae: Chloridoideae). Smithsonian Contributions to Botany 87(87): 1–50. https://doi.org/10.5479/si.0081024X.87
  • Peterson PM, Soreng RJ, Davidse G, Filgueiras TS, Zuloaga FO, Judziewicz EJ (2001) Catalogue of New World grasses (Poaceae): II. subfamily Chloridoideae. Contributions from the United States National Herbarium 41: 1–255.
  • Peterson P, Valdés-Reyna J, Herrera Arrieta Y (2007b) Muhlenbergiinae (Poaceae: Chloridoideae: Cynodonteae): from northeastern México. Journal of the Botanical Research Institute of Texas 1: 933–1000.
  • Peterson PM, Romaschenko K, Johnson G (2010a) A classification of the Chloridoideae (Poaceae) based on multi-gene phylogenetic trees. Molecular Phylogenetics and Evolution 55(2): 580–598. https://doi.org/10.1016/j.ympev.2010.01.018
  • Peterson PM, Romaschenko K, Johnson G (2010b) A phylogeny and classification of the Muhlenbergiinae (Poaceae: Chloridoideae: Cynodonteae) based on plastid and nuclear DNA sequences. American Journal of Botany 97(9): 1532–1554. https://doi.org/10.3732/ajb.0900359
  • Peterson PM, Romaschenko K, Soreng RJ (2014a) A laboratory guide for generating DNA barcodes in grasses: a case study of Leptochloa s.l. (Poaceae: Chloridoideae). Webbia 69(1): 1–12. https://doi.org/10.1080/00837792.2014.927555
  • Peterson PM, Romaschenko K, Herrera Arrieta Y, Saarela JM (2014b) A molecular phylogeny and new subgeneric classification of Sporobolus (Poaceae: Chloridoideae: Sporobolinae). Taxon 63(6): 1212–1243. https://doi.org/10.12705/636.19
  • Peterson PM, Romaschenko K, Herrera Arrieta Y (2015a) A molecular phylogeny and classification of the Eleusininae with a new genus, Micrachne (Poaceae: Chloridoideae: Cynodonteae). Taxon 64(3): 445–467. https://doi.org/10.12705/643.5
  • Peterson PM, Romaschenko K, Herrera Arrieta Y (2015b) Phylogeny and subgeneric classification of Bouteloua with a new species, B. herrera-arrietae (Poaceae: Chloridoideae: Cynodonteae: Boutelouinae). Journal of Systematics and Evolution 53(4): 351–366. https://doi.org/10.1111/jse.12159
  • Peterson PM, Romaschenko K, Herrera Arrieta Y (2016) A molecular phylogeny and classification of the Cynodonteae (Poaceae: Chloridoideae) with four new genera: Orthacanthus, Triplasiella, Tripogonella, and Zaqiqah; three new subtribes: Dactylocteniinae, Orininae, and Zaqiqahinae; and a subgeneric classification of Distichlis. Taxon 65(6): 1263–1287. https://doi.org/10.12705/656.4
  • Peterson PM, Herrera Arrieta Y, Romaschenko K (2018) Phylogeny of Muhlenbergia subg. Pseudosporobolus, including M. spatha (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) now found in Zacatecas, Mexico. PhytoKeys 103: 83–94. https://doi.org/10.3897/phytokeys.103.26162
  • Pfeiffer LKG (1874) Nomenclator botanicus 2(20). Theodori Fischeri, Kassel, 1081−1160.
  • Pirie MD, Humphreys AM, Galley C, Barker NP, Verboom GA, Orlovich D, Draffin SJ, Lloyd K, Baeza CM, Negritto M, Ruiz E, Cota Sánchez JH, Reimer E, Linder HP (2008) A novel supermatrix approach improves resolution of phylogenetic relationships in a comprehensive sample of danthonioid grasses. Molecular Phylogenetics and Evolution 48(3): 1106–1119. https://doi.org/10.1016/j.ympev.2008.05.030
  • Pohl RW (1980) Family #15, Gramineae. In: Burger WC (ed), Flora Costaricensis. Fieldiana Bot., n.s. 4: 1−608.
  • Reeder JR (1968) Notes on Mexican grasses VIII. Miscellaneous chromosome numbers–2. Bulletin of the Torrey Botanical Club 95(1): 69–86. https://doi.org/10.2307/2483808
  • Reeder CG (1985) The genus Lycurus (Gramineae) in North America. Phytologia 57: 283–291.
  • Reeder CG (2003) 17.34 Lycurus Kunth. In: Barkworth ME, Capels KM, Long S, Piep MB (Eds) Magnoliophyta: Commelinidae (in part): Poaceae, part 2 Flora of North America North of Mexico, Vol 25. Oxford University Press, New York, 200−203.
  • Renvoize SA (1998) Gramineas de Bolivia. The Royal Botanic Gardens, Kew, 1−644.
  • Saarela JM, Bull RD, Paradis MJ, Ebata SN, Peterson PM, Soreng RJ, Paszko B (2017) Molecular phylogenetics of cool-season grasses in the subtribes Agrostidinae, Anthoxanthinae, Aveninae, Brizinae, Calothecinae, Koeleriinae and Phalaridinae (Poaceae, Pooideae, Poeae, Poeae chloroplast group I). PhytoKeys 87: 1–139. https://doi.org/10.3897/phytokeys.87.12774
  • Sánchez E, Rúgolo de Agrasar ZE (1986) Estudio taxonómico sobre el género Lycurus (Gramineae). Parodiana 4: 267–310.
  • Soderstrom TR (1967) Taxonomic study of subgenus Podosemum and section Epicampes of Muhlenbergia (Gramineae). Contributions from the United States National Herbarium 34: 75–189.
  • Soreng RJ, Peterson PM, Romaschenko K, Davidse G, Teisher JK, Clark LG, Barberá P, Gillespie LJ, Zuloaga FO (2017) A worldwide phylogenetic classification of the Poaceae (Gramineae) II: An update and a comparison of two 2015 classifications. Journal of Systematics and Evolution 55(4): 259–290. https://doi.org/10.1111/jse.12262
  • Standley PC (1936) Gramineae. In: Macbride JF (Ed.) Flora of Peru. Publications of the Field Museum of Natural History, Botanical Series 13: 96−261.
  • Sutherland CN (1997) Material tipo de la coleccíon de Sessé y Mociño en el Real Jardín Botánico de Madrid. Annales Jardín Botánico de Madrid 55: 375–418.
  • Tovar Ó (1993) Las Gramíneas (Poaceae) del Perú. Ruizia 13: 1–480.
  • Verboom GA, Linder HP, Stock WD (2003) Phylogenetics of the grass genus Ehrharta: Evidence for radiation in the summer-arid zone of the South African Cape. Evolution; International Journal of Organic Evolution 57(5): 1008–1021. https://doi.org/10.1111/j.0014-3820.2003.tb00312.x
  • Weberbauer A (1936) Phytogeography of the Peruvian Andes. In: Macbride JF (Ed.) Flora of Peru. Publications of the Field Museum of Natural History, Botanical Series 13: 13−81.
  • Welker CAD, Souza-Chies TT, Longh-Wagner HM, Carolina Peichoto M, McKain MR, Kellogg EA (2016) Multilocus phylogeny and phylogenomics of Eriochrysis P. Beauv. (PoaceaeAndropogoneae): Taxonomic implications and evidence of interspecific hybridization. Molecular Phylogenetics and Evolution 99: 155–167. https://doi.org/10.1016/j.ympev.2016.02.022
  • Wu Z, Peterson PM (2006) 140. Muhlenbergia. In: Wu ZY, Raven PH, Hong DY (Eds) Flora of China: Poaceae, volume 22. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, 486–487.