Agrostis and Podagrostis (Agrostidinae, Poaceae) from páramos of Boyacá, Colombia: synoptic taxonomy including a key to Colombian species

Abstract We present taxonomic notes, including updated species descriptions and images, for the nine species of Agrostis and one species of Podagrostis found in páramos of Departamento Boyacá, Colombia (A.boyacensis, A.breviculmis, A.capillaris, A.foliata, A.cf.imberbis, A.mertensii, A.perennans s.l., A.stolonifera, A.tolucensis, Podagrostistrichodes). Agrostiscf.imberbis, previously known from austral South America, is newly recorded for Colombia, A.capillaris is a new regional record for Boyacá, and the name Agrostisstuebelii is lectotypified. We include keys in English and Spanish to distinguish the 15 species of Agrostis and two species of Podagrostis that are cited as occurring in Colombia.


Introduction
The grass genera Agrostis L. and Podagrostis (Griseb.) Scribn. & Merr. belong to tribe Poeae R.Br., subtribe Agrostidinae Fr., with molecular data supporting their close relationship (Saarela et al. 2017). They both share numerous morphological characteristics, including paniculate, single-flowered laterally-compressed spikelets that disarticulate above the glumes, while lacking characteristics such as notably pubescent calluses and prominent rachilla prolongations that define the related genera once placed in Calamagrostis Adans. s.l. (Peterson et al. 2019;Sylvester et al. 2019a). Indeed, Podagrostis was originally described as a section of Agrostis and considered to be limited to just one species in Austral South America and three species from North America . Recent taxonomic research in Colombia has, however, discovered two new species of Podagrostis for South America, with P. colombiana Sylvester & Soreng being found from the páramos of the Sierra Nevada de Santa Marta, Colombia (Sylvester et al. 2019b), and the common High-Andean grass Agrostis trichodes (Kunth) Roem. & Schult. being transferred to Podagrostis (Sylvester et al. 2020). Aside from these studies, the only other published taxonomic research related to the genus Agrostis in Colombia is mostly limited to type protologues and checklists, some with a single voucher cited (Luteyn 1999;onwards;Giraldo-Cañas 2011, 2013Giraldo-Cañas et al. 2016), with no taxonomic revisions or keys to the species existing for the genus in Colombia. Palacio et al. (in press) recently described the new species Agrostis laegaardiana A.M. Molina & Rúgolo, from Ecuadorian and Colombian páramos, and provided a brief key to distinguish morphologically similar species with condensed spikelike panicles from these habitats. With this, coupled with the new record of Agrostis cf. imberbis Phil. described herein and not including the new combination Podagrostis trichodes (Kunth) Sylvester & Soreng (Sylvester et al. 2020), Colombia is believed to hold 15 species of Agrostis, including three possible endemics, and three exotic species Palacio et al. in press).
Neighboring Ecuador and Venezuela also lack comprehensive taxonomic treatments for Agrostis: Ecuador has the aforementioned recent paper that describes A. laegaardiana and includes a brief key to similar species (Palacio et al. in press), checklists (Jørgensen and Ulloa-Ulloa 1994;Jørgensen and León-Yánez 1999) and Hitchcock's (1927) synoptic treatment available; Venezuela has checklists Bono 2010) plus synoptic treatments for different regional areas (Briceño 2010;Dorr 2014). Thus, researchers have only these plus treatments from Central America Pohl and Davidse 1994;Morales-Quirós 2003) and further south, such as those from Peru (Tovar 1993), Bolivia (Renvoize 1998) and Argentina (Rúgolo de Agrasar 2012), to help identify Agrostis taxa in Colombia.
The majority of Agrostis taxa cited for Colombia Palacio et al. in press) are found in high-elevation páramo grasslands. These ecosystems are located above the montane treeline of the humid tropical Andes from northern Peru to Colombia and Venezuela, with isolated regions also found in the mountains of Costa Rica and Panama (Luteyn 1999;Peyre et al. 2018). Páramos are classified as one of the world's 34 biodiversity hotspots (Myers et al. 2000), with their high diversity and endemism probably a result of a unique geological and climatological history (Flantua et al. 2019). Colombia hosts the largest area of páramo of any country, holding 49% of the world's páramo, which is an estimated c. 2 million hectares of national territory with the lower elevational limit ranging between 2850 and 3550 m alt. (Morales et al. 2007). Colombian páramos can be separated into five main high-elevation island-like enclaves within the country, namely the Cordillera Oriental, the Cordillera Central, the Cordillera Occidental, the Sierra Nevada de Santa Marta, and páramos of Nariño-Putumayo (Morales et al. 2007;Peyre et al. 2018). Roughly 60% of Colombia's páramos are found in the Cordillera Oriental, with the political region (termed 'Departamento') Boyacá being especially important and hosting the largest area of páramo of any Departamento in Colombia, calculated at 19% of Colombia's overall páramo (Morales et al. 2007). When conducting fieldwork in the páramos of Boyacá, Agrostis was found to be the most locally diverse grass genus (Sylvester pers. observation; unpubl. data), but with a notable dearth of taxonomic information available to help identify specimens. To support ecological and taxonomic research in Colombia's páramos, we present a key to the species of Agrostis and Podagrostis currently (sometimes tentatively) accepted in Colombia, and short descriptions, images, and notes for the species found in páramos of Departamento Boyacá, Colombia.

Materials and methods
Accepted species follow Soreng et al. (2003 and onwards). Herbarium acronyms follow Thiers (continuously updated). In this treatment, glabrous means without pubescence (in the sense of slender, relatively soft hairs unless otherwise stated). 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 rough or scabrous surface can be glabrous). Taxonomic notes, including updated short descriptions mentioning the most important taxonomically informative characters for delineating species, are found for the eight species encountered during extensive fieldwork in the páramos of Boyacá. Agrostis subrepens (Hitchc.) Hitchc., which is mentioned in Giraldo-Cañas et al. (2016) as occurring in Departamento Boyacá, and A. gigantea Roth, A. scabrifolia Swallen and A. lehmannii Swallen, which are cited for Colombia in general , are placed in the 'Excluded species' section at the end of the taxonomic treatment as no specimens were verified from Boyacá. Agrostis meyenii Trin., not registered for Colombia ), but which may occur there, is also included in the key. Notable synonyms of taxa found in Colombia or neighboring countries are included. The descriptions in the taxonomic notes were made based on specimens studied in both Colombia and neighboring countries, as well as information found in type protologues and literature Tovar 1993;Pohl and Davidse 1994;Renvoize 1998;Morales-Quirós 2003;Briceño 2010;Rúgolo de Agrasar 2012;Dorr 2014). Only specimens studied from Departamento Boyacá are cited, or, exceptionally, specimens of interest from other Departamentos within Colombia are also cited. Specimen localities are cited by country (capital letters), political region (also historically called 'departamento'; in bold) and then municipality. The herbaria COL, FMB, K, UPTC, and US were visited during the study. Only herbaria where specimens have been checked and verified by the authors have been cited.

Taxonomic treatment
Identification key to the 15 species of Agrostis and two species of Podagrostis that are cited in Colombia (species that have not been confirmed by us to occur in Colombia are placed in brackets; Agrostis meyenii, which may occur in Colombia, but has so far not been registered, is also included)   (1) Leaf blades involute or convolute; panicles < 5 cm long; floret equalling or subequalling the glumes, usually with a short glabrous, smooth or scabrous rachilla emerging from under the palea (some spikelets within the inflorescence may lack the rachilla prolongation, so needs checking carefully); paleas reaching from (2/3) ¾ the length of the lemma to almost the apex of the lemma; lemmas muticous or with a short straight awn 0.2-0.5 mm long, inserted medially or in the upper half of the lemma, not surpassing the glumes.......16 -Leaf blades generally flat (A. capillaris often with basal blades involute and culm blades flat); panicles generally > 5 cm long (sometimes to 2 cm long in A. stolonifera or 3 cm in A. capillaris); floret notably shorter than the glumes, usually 1/3-3/4 the length of the glumes, without a rachilla prolongation; paleas reaching from (2/5-)2/3-3/4 the length of the lemma; lemmas muticous or with an awn of varying length, ranging from a short straight awn, 0. (1) Láminas foliares involutas o convolutas; panículas < 5 cm de largo; antecio que iguala o sub-iguala a las glumas, usualmente con una raquilla corta, glabra, lisa o escabrosa que emerge por debajo de la pálea (algunas espiguillas dentro de la inflorescencia pueden carecer de la prolongación de la raquilla, por ello se necesita revisar cuidadosamente); paleas que alcanzan desde (2/3) ¾ la longitud de la lema a casi el ápice de la lema; lemas múticas o con una arista corta y recta 0. Description. Annuals or perennials. Leaves basal or cauline; ligules membranous to scarious. Inflorescence a panicle, lax and open to contracted and spikelike. Spikelets 1-flowered, disarticulating above the glumes, laterally compressed; glumes as long as the spikelet, equal or subequal, persisting on the plant after the florets have fallen, usually 1-veined, rarely 3-veined; floret usually notably shorter than the glumes or reaching to ¾ the length of the glumes, exceptionally longer; lemmas membranaceous or hyaline, generally thinner than the glumes, dorsally rounded, 3-or 5-veined, veins not or distinctly evident; paleas often absent or noticeably shorter than the lemma, sometimes reaching to ¾ the length of the lemma, hyaline and slightly to notably thinner than the lemmas, keels usually obscure, rarely distinct, glabrous, usually smooth, rarely scaberulous; calluses rounded, glabrous or pubescent and usually with 2 lateral tufts of short hairs; rachilla prolongation absent. Flowers perfect; anthers 3 in number, 0.3-1.8 mm long. Caryopses hard (in species from Colombia) or sometimes with liquid endosperm.
Notes. In Colombian páramos, taxa of Agrostis can be most easily confused with those of Calamagrostis s.l. (i.e., Cinnagrostis Griseb., Deschampsia P. Beauv., Paramochloa P.M. Peterson, Soreng, Romasch. & Barberá, Peyritschia E. Fourn.; Peterson et al. 2019;Sylvester et al. 2019a), Podagrostis, Polypogon Desf., and Sporobolus R. Br. The genera previously circumscribed as Calamagrostis s.l. (Peterson et al. 2019;Sylvester et al. 2019a) can usually be differentiated by a combination of a prolonged hairy rachilla emerging from the base of the floret, a well-developed palea, a hairy callus, an awn present and inserted dorsally on the lemma, and an upper glume with well-developed lateral veins, although certain species are missing some of these characteristics (see Sylvester et al. 2019a). Polypogon is principally differentiated by spikelets that disarticulate below the glumes, with the grain, lemma, palea, glumes and part of the pedicel falling together. The glumes are also often awned in Polypogon. Sporobolus is principally differentiated by its ligule in the form of a line of hairs, its well-developed paleas with the same consistency as the lemma, and the lemmas being 1(-3) veined. Description. Perennial herbs, densely tufted, often stooling with perenniating many-branched culms, often with short lateral tending to ascending rhizomes. Tillers extravaginal, with cataphyllous shoots present. Culms 3−24 cm tall (to 37 cm tall in specimens from Boyacán páramos outside the Sierra Nevada del Cocuy), erect to arched, firm, with 0(−2) nodes exerted at flowering, densely scabrous throughout or scabrous just below the nodes, or rarely smooth (specimens from Boyacán páramos outside the Sierra Nevada del Cocuy). Leaves basal and cauline, often mainly basal, glabrous, usually densely scabrous throughout, less often smooth or scaberulous (specimens from Boyacán páramos outside the Sierra Nevada del Cocuy); ligules 0.9−2 mm long, membranous or slightly scarious, truncate to triangular and obtuse, moderately to strongly decurrent with the sheath, abaxial surface smooth or scaberulous; blades (2−)3−6(−12) cm long, 0.5−1.2(−1.5) mm in diameter as folded or rolled, convolute, involute, or strongly conduplicate, usually recurved or sometimes straight, firm to rigid, those of upper culm sometimes flat, firm, 2−3 mm wide, abaxial surface usually densely scabrous throughout, less often smooth to scaberulous (specimens from Boyacán páramos outside the Sierra Nevada del Cocuy), adaxial surface and margins moderately to densely scabrous, apices blunt or slightly naviculate-acute. Panicles (2−)3−6(−8) cm long, c. 0.3−0.7(−0.9) cm wide, moderately to densely congested, sub-spikelike to spikelike, generally not interrupted, subincluded in the basal foliage to greatly exerted, lateral branches with spikelets usually present almost to the base, upper lateral branches short and held close to the central inflorescence axis, central axis and panicle branches moderately to densely scabrous, rarely smooth or scaberulous (specimens from Boyacán páramos outside the Sierra Nevada del Cocuy); pedicels 0.8−2.5 mm long, usually shorter than their spikelets, not obviously dilated at their apex, moderately to densely scabrous, sometimes smooth or scaberulous (specimens from Boyacán páramos outside the Sierra Nevada del Cocuy). Spikelets 1.8−2.4(−2.5) mm long; glumes usually unequal, sometimes subequal, the lower longer than the upper by up to 0.3 mm and usually wider than the upper, 1-veined, lower glume keel scabrous throughout to only in distal 1/3, upper glume scabrous only in the distal 1/3 or sometimes smooth throughout, apices acute; floret 3/5−2/3(−3/4) the length of the glumes; calluses glabrous or with 2 sparse tufts of very short hairs on the lateral sides; lemmas 1−1.5 mm long, glabrous, smooth, 5-veined, apex obtuse to slightly truncate, erose, muticous or exceptionally with a short straight awn inserted in the upper ½ of the lemma, to 0.5 mm long, not sur- passing the glume apex, weak and falling easily (i.e. Sylvester 3071); paleas absent or to 0.3 mm long, < ¼ the length of the lemma; rachilla absent; anthers 0.5−0.8(−1) mm long.

Agrostis boyacensis
Distribution and ecology. Colombia, Ecuador?. Páramos and superpáramos, found in both zonal grass páramo and azonal high elevation moraine, 2850-4500 m alt. Within Colombia, the species seems to be found only in the Cordillera Oriental, with specimens only seen from Departamento Boyacá. Luteyn (1999) mentions the species to be found in Ecuador and the species is also mentioned in the key to some Ecuadorian taxa (Palacio et al. in press) Notes. Specimens encountered from páramos not belonging to the Sierra Nevada del Cocuy, but within Departamento Boyacá, bear notable differences from those from the type locality and further study is needed to elucidate whether these are a distinct species or subspecies of A. boyacensis. These differences include leaf sheaths and blades, panicle branches, and pedicels being usually smooth or very lightly scaberulous, and plants being larger, usually > 20 cm tall and up to 37 cm tall, and with the panicles largely exerted from the basal foliage (Fig. 2). These characteristics place it close to A. meyenii, which is not known from Colombia  or páramos in general (Luteyn 1999), although it is mentioned in the recently-published abbreviated key to some Ecuadorian species (Palacio et al. in press) (see below for how to differentiate these species).
The habit of type specimens and some of the other specimens examined (e.g. Sylvester 3117 and 3129), with perenniating, many-branched culms, appears to be related to the habitat, with the Sylvester 3117 and 3129 specimens being found growing amongst moss. The leaf blades of these were also slightly laxer, albeit still involute or strongly conduplicate. In harsher conditions, such as open gravelly slopes, the tufts are more compact and leaf blades are rigid and strongly rolled and resemble a very large, densely-tufted A. breviculmis with slightly laxer panicles.
Similar species. Agrostis breviculmis and A. meyenii both have congested spikelike panicles and florets that lack prominent awns and well-developed paleas. Agrostis breviculmis bears close similarity in its convolute, often recurved, rigid to firm leaf blades that usually measure < 1 mm wide in diameter, and small spikelets with fairly well developed coarse scabers on the glume keels. Agrostis boyacensis can be distinguished from A. breviculmis principally by the habit, with many extravaginally branched culms that form large dense tufts to 37 cm tall (vs. intravaginal innovations forming short tufts to 12(−15) cm tall in A. breviculmis), laxer panicles, 3-9 mm wide (vs. c. 0.5−2 mm wide in A. breviculmis), and slightly larger spikelets, 1.8-2.4(-2.5) mm long (vs. usually 1.5-2.1 mm long in A. breviculmis, noted to reach 2.5 mm long in Bolivia [Renvoize 1998]).
Agrostis boyacensis can be distinguished from A. meyenii principally by its robust convolute, involute or strongly conduplicate, usually recurved and rigid leaf blades (vs. laxer, weaker, flat or folded, usually filiform leaf blades in A. meyenii). All specimens encountered from the Sierra Nevada del Cocuy can be easily differentiated by their panicle branches, pedicels, and leaf sheaths and blades that are moderately to densely scabrous (vs. panicle branches and pedicels smooth to lightly scaberulous, leaf sheaths smooth, blades smooth or scabrous in A. meyenii). Specimens collected in other páramos from Departamento Boyacá, outside of the Sierra Nevada del Cocuy, bear further similarities with A. meyenii, such as their culms and inflorescences being longer and greatly exerted from the basal foliage, and panicle branches, pedicels, and leaf blades that are usually smooth to lightly scaberulous (Fig. 2). Nevertheless, these can be differentiated from A. meyenii by a) their robust convolute, involute or strongly conduplicate, rigid and usually recurved leaf blades; b) the glumes usually being unequal, with the lower glume longer and usually wider than the upper; and c) the lower glume keel scabrous throughout to only in distal 1/3, the upper glume keel scabrous only in the distal 1/3 or sometimes smooth throughout.
Agrostis tolucensis has a congested spikelike panicle and florets with a minute palea and a lemma that can sometimes lack awns (see notes under A. tolucensis). This species usually has leaf blades filiform, flat, or folded, lax to firm, but can sometimes have basal leaf blades involute or convolute and firm to rigid. All specimens examined at US with involute or convolute and rigid leaf blades had lemmas with a well-developed dorsally inserted awn. Further distinction from A. boyacensis can be found in how the leaf blades are smooth or scabrous only on the margin and sometimes veins in A. tolucensis, while scabrous throughout (margin, veins, and in-between veins) in A. boyacensis from the Sierra Nevada del Cocuy, although A. boyacensis specimens from other Boyacan páramos have blades smooth to scaberulous.
The sometimes strongly conduplicate leaf blades of this species can also give it a resemblance to A. foliata, which has subcoriaceous to coriaceous leaf blades that can sometimes be folded, although these are usually > 1.5 mm wide when opened out, and lemmas with well-developed awns inserted in the lower 1/2 of the lemma.  Description. Perennial herbs, densely tufted, not stooling and without notable lateral tending or ascending rhizomes. Tillers intravaginal, without cataphylls. Culms 3−12(−15) cm tall, erect to arched, firm, usually with 0 nodes exerted at flowering. Leaves basal, glabrous, smooth or scaberulous; ligules c. 1 mm long, membranous or slightly scarious, triangular and obtuse, moderately to strongly decurrent with the sheath, abaxial surface smooth or scaberulous; blades 1−4(−6) cm long, 0.25−1 mm wide in diameter as folded or rolled, usually convolute, less often strongly conduplicate, recurved, rigid, abaxial surface usually smooth throughout, rarely scaberulous towards the apex, adaxial surface and margins generally scaberulous, sometimes moderately scabrous, apices blunt to slightly broadly naviculate-acute. Panicles 1−2.6(−3) cm long, c. 0.05−0.2(−0.6) cm wide, densely congested, spikelike, generally uninterrupted, subincluded in the basal foliage to slightly or moderately exerted, lateral branches with spikelets almost to the base, upper lateral branches short and held close to the central inflorescence axis, central axis and panicle branches scabrous or smooth; pedicels 0.9−2 mm long, usually shorter than their spikelets, not obviously dilated at their apex, smooth or scaberulous. Spikelets 1.5−2.1 mm long (−2.5 mm long in Bolivia?; Renvoize 1998); glumes equal or subequal, lower glume sometimes longer than upper by up to 0.2 mm and slightly to notably wider, 1-veined, lower glume keel scabrous at least in the distal half, prickle hairs coarse and shiny, upper glume keel like that of lower glume or with fewer scabers to sometimes smooth throughout, apices acute; floret 2/3−3/4 the length of the glumes; calluses pilose, usually with 2 lateral tufts of short hairs; lemmas 1.2−1.4 mm long, glabrous, smooth, 5-veined, apex truncate, erose and 4-mucronate, muticous or with a short straight awn to 0.9 mm long, inserted above the middle, not or only briefly surpassing the glume apex, weak and falling easily; paleas absent or to 0.3 mm long, < ¼ the length of the lemma; rachilla absent; anthers 0.5−0.9 mm long.  (Palacio et al. in press), also bears very close resemblance. These similarities include: a) plants 3-12 cm tall; b) tillers intravaginal, without notable lateral tending or ascending rhizomes; c) leaf blades convolute, recurved, rigid, 0.5-2 mm wide when opened out, apices blunt or slightly naviculate-acute; d) ligules c. 1 mm long; and e) glumes with coarse shiny prickle hairs along the keel. Agrostis breviculmis can be differentiated from A. laegaardii by a) often larger spikelets, (1.7-)2-3.3 mm long (vs. 1.5-2.1(-2.5) mm long in A. breviculmis); b) pedicels slightly widened towards the apex and cupuliform (vs. pedicel apex not dilated, truncate, in A. breviculmis); c) glumes membranous, standard V-shaped in cross section (vs. chartaceous, narrow V-shaped in cross section in Description. Perennial herbs, loosely to densely tufted with short to extensive rhizomes and sometimes with well-developed stolons. Tillers extravaginal, with cataphylls present. Culms 10−80 cm tall, erect or decumbent at their base, delicate, usually with 2−5 nodes exerted at flowering, smooth or scaberulous. Leaves basal and cauline, glabrous, smooth or scaberulous; ligules 0.2−1.5(−2.9) mm long, of basal leaves and tillers ≤ 1 mm long, distinctly shorter than wide, of culm leaves 0.5-1.5(-2.9) mm long, membranous, rounded to truncate, not or only slightly decurrent with the sheath, abaxial surface scaberulous to sometimes smooth; blades 1−17 cm long, (0.6−)1−5 mm wide as opened out, basal blades and those of tillers often involute and 0.3-0.8 mm wide as rolled, sometimes flat, culm blades generally flat or becoming convolute upon drying, less often involute, usually soft and lax, rarely firm, abaxial and adaxial surfaces and margins smooth or scaberulous. Panicles 3−20 cm long, 2.5−8 cm wide, usually open, sometimes partially closed after flowering, lax, usually ovoid to pyramidal, subincluded in the basal foliage to greatly exerted, lateral branches without spikelets in the lower ½, long, ascending or spreading but not held close to the central inflorescence axis, central axis and panicle branches scabrous or smooth; pedicels 1−2 mm long, usually shorter than their spikelets, dilated or not at their apex, smooth or scaberulous. Spikelets (not including awn, if present) (1.8−)2−2.5(−2.7) mm long; glumes subequal, the lower slightly longer than the upper, 1-veined, lower glume keel usually scabrous in the distal half, sometimes scabrous throughout, upper glume keel often smooth throughout, infrequently scabrous in the distal half, apices acute; floret 2/3−3/4 the length of the glumes; calluses glabrous or with 2 sparse lateral tufts of short hairs; lemmas 1.4−2.2 mm long, 3-or 5-veined, glabrous or sometimes pubescent at the base when 5-veined, smooth, apex obtuse or truncate, erose, muticous or with an awn 0.5−3 mm long, inserted above the middle of the dorsal keel, exerted from the glumes or not, straight, flexuose or geniculate, twisted or not, weak and easily falling, usually found only on the 5-veined lemmas; paleas 0.6−1.3 mm long, (2/5−)½−¾ the length of the lemma; rachilla absent; anthers 0.8−1.4 mm long.

Agrostis breviculmis
Distribution and ecology. Eurasian, introduced to the north of South America. Predominantly found in grazed páramo and puna vegetation. Agrostis capillaris is here recorded as a new regional record for the Depto. Boyacá of Colombia. Giraldo-Cañas et al. (2016) mention it as an introduced and cultivated herb based on the record of A. tenuis by Hafliger and Scholz (1981). It is likely to be an under-recorded element in many Colombian regions with páramo habitat.
Other specimen examined. capillaris. Other characters, such as awn presence, are too variable to be useful in separating these species. Furthermore, these species can also hybridize to produce A. × foilladei P. Fourn., which has been reported from seed mixtures for amenity grassland in the UK (Cope and Gray 2009). Agrostis gigantea, another closely related species which can usually be readily distinguished by its greater size and relatively longer ligules, does have some smaller variants with thinner leaves that superficially resemble A. capillaris, but the ligule will always settle the identity. Description. Perennial herbs, tussock-forming or laxly to densely tufted, usually with short ascending rhizomes. Tillers extravaginal and intravaginal, with cataphylls usually present. Culms 15−30 cm tall, erect, rigid and thickened, with 0 nodes exerted at flowering, smooth or scaberulous. Leaves usually more-or-less evenly spread along the culm, sometimes congested basally, glabrous, usually densely scabrous; ligules 3−8 mm long, of upper culm 4−8 mm long, usually scarious (at least in part), triangular and obtuse to acute, moderately to strongly decurrent with the sheath, abaxial surface scaberulous to scabrous; blades 3−12 cm long, 2−6 mm wide when opened out, flat or folded, sometimes somewhat involute towards their apices, straight or slightly recurved, subcoriaceous to coriaceous, surfaces and margins usually densely scabrous throughout, apices naviculate-acute. Panicles 5−12.7 cm long × 1−1.7(−2.5) cm wide, densely congested, spikelike, sometimes interrupted towards the base, usually exerted from the basal foliage or sometimes subincluded, lateral branches with spikelets usually present almost to the base, upper lateral branches short and held close to the central inflorescence axis, central axis and panicle branches moderately to densely scabrous; pedicels 0.7−4 mm long, usually shorter than their spikelets, not obviously dilated at their apex, scabrous. Spikelets (not including awn) 3-4.2 mm long; glumes equal or subequal, 1-veined, keels smooth or lightly scabrous, surfaces smooth, apices acuminate; floret usually c. ½ the length of the glumes, rarely slightly longer; calluses pilose with 2 sparse tufts of short hairs on the lateral sides; lemmas 1.5−2 mm long, glabrous, smooth, 5-veined, apex truncate, denticulate, awned, awn 2−2.8 mm long, inserted in the lower ½ of the dorsal keel, exerted from the glumes, geniculate, twisted, persistant;  Notes. Two syntypes of A. stuebelii were noted in Pilger's protologue of Agrostis stuebelii. We lectotypify the name on the best material at US that includes one flowering and one non-flowering plant, with the bases of the plants well preserved. We were unable to locate the two duplicates of the lectotype at B, from which the US material was taken.
Distribution and ecology. Agrostis cf. imberbis is a new record for Colombia and páramo vegetation in general, and is not found in the most recent checklist for Colombia , the páramo checklist (Luteyn 1999) or checklists for Ecuador (Jørgensen and Ulloa-Ulloa 1994;Jørgensen and León-Yánez 1999), Venezuela Bono 2010), or Costa Rica (Morales-Quirós 2003) which host páramo vegetation. The species was previously considered to be restricted to Ar-gentina and Chile (Rúgolo de Agrasar 2012), but has also been recorded for Bolivia (Jørgensen et al. 2014) and Peru (Davidse et al. 1993;Soreng et al. 2003 and onwards;W3TROPICOS-Peru Checklist 2020;Óscar Tovar unpubl. data Notes. Specimens studied from Boyacá match most characteristics of A. imberbis apart from sometimes the leaf blade abaxial surfaces being scaberulous, albeit with silica 'pustules' present throughout that sometimes developed into short hooks, and spikelets sometimes being shorter, to 2.3 mm long. Rúgolo de Agrasar (2012) mentions leaf blades can be smooth in A. imberbis under exceptional circumstances. Characters that are diagnostic for the species, such as narrow, rolled (convolute or involute) or conduplicate, rigid blades, long acuminate scarious ligules, usually large spikelets > 2.5 mm long, and glabrescent calluses, were all present on the specimens studied from Boyacá. Given its disjunct distribution and slight differences in morphology, coupled with knowledge that other widespread species such as A. perennans are actually numerous evolutionarily distinct taxa (Konstantin Romaschenko pers. communication), we refer to this species with 'cf.' to highlight that it needs to be checked in a molecular framework. The species has a variable level of panicle congestion depending on the stage of maturity.
Similar species. Agrostis subrepens, a species described from Mexico and whose presence in Colombia is uncertain (see notes on A. subrepens under 'Excluded species' at the end of the taxonomic treatment), and A. cf. imberbis share similar morphologies. This includes the habit being decumbent and stooling, appearing rhizomatous or pseudostoloniferous, blades being convolute and rigid, and panicles usually large and open with spikelets that have a similar shape and size with lemmas lacking notable awns, ligules being strongly decurrent with the sheath and usually scarious (at least in part), and anthers > 1 mm long. While culm and panicle size are generally larger and anthers are often shorter in A. subrepens, some overlap occurs with A. imberbis, with ligule shape and size seeming to be the only solid character to differentiate them. Agrostis subrepens has shorter (< 2.2 mm long), obtuse upper culm ligules while A. cf. imberbis has acute to acuminate upper culm ligules (2.8−)3−6.7(−10) mm long.
Agrostis perennans s.l. can sometimes have involute and rigid basal blades, but the upper culm blades are flat and lax, unlike those of A. cf. imberbis, which are rigid and convolute, involute, or strongly conduplicate throughout. The ligules in A. perennans s.l. are also usually shorter, with ligules of basal leaves and tillers 0.5−2.5 mm long, while those of A. cf. imberbis are > 2.5 mm long. Ligule apices of A. perennans s.l. are also truncate or obtuse-triangular, unlike the acute or long acuminate ligules of A. cf. imberbis.
Agrostis vinealis Schreb., a species not recorded for Colombia, but found introduced and naturalized in Argentina and Chile Rúgolo de Agrasar 2012), bears similarities in terms of overall habit, being notably rhizomatous and having mainly basal leaves and an exerted open panicle that becomes congested after flowering, as well as other similarities such as the palea being reduced and awns sometimes absent (but usually with a persistent, geniculate and twisted, awn to 4 mm long, inserted near the base of the lemma). Agrostis vinealis usually has leaf blades that are flat towards the base, although sometimes these are involute and setaceous, and scabrous throughout or at least on the adaxial surface. It can also be differentiated by the ligules being often shorter, of the tillers 1−2.5 mm long, of the upper culms 1−4(−5) mm long, with apices rounded or bluntly pointed (vs. of the tillers > 2.5 mm long, of the upper culms (2.8−)3−6.7(−10) mm long, with apices acute to acuminate in A. cf. imberbis).
Distribution and ecology. Exhibits a disjunct distribution, being found in very cold Arctic and sub-Arctic areas of the Northern Hemisphere (i.e. North America, Europe and Asia), and also in the high Andes of Venezuela, Colombia, Peru, Bolivia, Argentina and Chile   Notes. This species is highly variable in terms of its habit, the form of its leaf blades (flat or involute) and ligule (short and obtuse to long and acuminate), and the form of the panicle (panicle branches adpressed and congested when young while open when mature). The combination of open panicle (when mature), lemma with a dorsally inserted awn, and a minute or absent palea are diagnostic for this species.
Similar species. Agrostis perennans s.l., which can be principally differentiated by the absence of an awn, or if awn present, this being inserted in the upper half of the dorsal surface of the lemma or subapically and to 0.5 mm long. Agrostis pittieri Hack., considered endemic to Costa Rica by  and Morales-Quirós (2003), also bears close similarity to A. mertensii and may be placed as a synonym of the latter in future research. Hokche et al. (2008) and Dorr (2014) record A. pittieri for Venezuela, with Dorr (2014) stating A. pittieri can be tentatively differentiated by having linear and narrow panicles with green spikelets and lemmas 1.9−2 mm long, while A. mertensii has broadly ovate to lanceolate panicles with purple spikelets and lemmas 2−2.5 mm long. However, these characters' overlap in specimens studied from throughout the range of A. mertensii.  Description. Perennial herbs, laxly to densely tufted, sometimes stooling or with short ascending pseudostolons that have the appearance of rhizomes on herbarium sheets. Tillers extravaginal, with cataphylls present. Culms (21−)33−64(−100) cm tall, erect or decumbent to subgeniculate at their base, delicate to fairly firm, with 0−2(−3) nodes exerted at flowering, smooth to rarely scaberulous. Leaves mainly basal early in the flowering season but tending to become mostly cauline with maturity, glabrous, smooth or scaberulous; ligules 0.5−5(−7) mm long, of basal leaves and tillers 0.5−2.5 mm long, of upper culm 3−5(−7) mm long, truncate to obtuse-triangular, slightly to strongly decurrent with the sheath, abaxial surface scabrous to scaberulous, rarely smooth; blades (3−)6−15 cm long, (1-)1.5−3.5(−5) mm wide, usually flat or conduplicate and lax to slightly firm, sometimes involute and rigid in the basal leaves, smooth throughout or scaberulous on margins and sometimes surfaces, apices acute. Panicles (3.5−)10−22 cm long, 2−11 cm wide, open, lax, ovoid to pyramidal, slightly to usually greatly exerted from the basal foliage, lateral branches without spikelets near their base and for a large distance, long, ascending, spreading, to somewhat divergent and not held close to the central inflorescence axis, central axis and panicle branches smooth or lightly scaberulous; pedicels 1−4.5 mm long, usually longer than their spikelets, not or slightly dilated at their apex, smooth or lightly scaberulous. Spikelets (not including awn, if present) (1.5−)1.8−2.5(−3.2) mm long; glumes subequal, 1-veined, keels scabrous in the distal ½−1/3, apices acute; floret usually 1/2−2/3 the length of the glumes, rarely longer; calluses lightly pilose with 2 sparse lateral tufts of short hairs; lemmas 1.5−2 mm long, glabrous, smooth, 5-veined, apex acute to more-or-less truncate, denticulate, muticous, mucronate or exceptionally with a short awn to 0.5 mm long (to 1.4−1.9 mm long in Argentina; Rúgolo de Agrasar 2012), inserted in the upper (½) 1/3 of the dorsal keel, usually not or rarely only slightly surpassing the glumes, straight, not twisted, weak and falling easily; paleas absent or to 0.5 mm long, usually < ¼ the length of the lemma; rachilla absent; anthers 0.7−1 mm long.

Agrostis perennans
Distribution and ecology. Stretching from Alaska, Canada and USA, through Central America and the Caribbean, to Argentina and Chile of South America. The species has an exceptionally large ecological amplitude, being found in maritime dunes, wetlands, and grasslands from sea level to > 4000 m alt.
Other specimens examined. Colombia. Boyacá: Munic. Belén, Páramo de La Rusia, near Páramo El Consuelo, unprotected private land, somewhat disturbed páramo grazed by horses and rodents, with Espeletia boyacensis and E. discoides, near path, 6. 02415N, 72.57289W, 3831, 22 Nov. 2017 Notes. Agrostis perennans appears to be a 'grab-bag' of many different taxa that come out in many different places amongst other taxa of Agrostis in molecular phylogenies (Konstantin Romaschenko pers. communication), with the species complex needing urgent revision. Specimens found in Boyacán páramos correspond in almost all characteristics with Agrostis perennans s.s. apart from sometimes being found with shorter spikelets (c. 1.5−2 mm long) and, what appear to be, short ascending rhizomes/pseudostolons, with these characteristics also found on type material of A. fasciculata, which is here considered a synonym of A. perennans until comprehensive systematic research is undertaken on the species complex. Cataphyllous extravaginal shoots are found on the neotype of A. perennans as well as other type material of species considered synonyms of A. perennans, e.g. A. decumbens E. Fourn., with it plausible that these 'rhizomes' are short pseudostolons that arise from growing through moss or between rocks.
Type specimens and specimens from North America, Central America, and northwest South America have lemmas without awns or with awns under-developed, to 0.5 mm long, straight and easily falling. Specimens noted by Rúgolo de Agrasar (2012: 119) to have awns to 1.4 mm long, or exceptionally to 1.9 mm long, may be a distinct taxon, but further research is needed to ascertain this. Similar species. Agrostis mertensii, which is principally differentiated in having a well-developed, flexuose to geniculate, twisted awn (1.8−)2.5−4.5 mm long, inserted in the middle or lower third of the lemma, and which is greatly exerted from the glumes (vs. unawned or exceptionally with a short straight awn to 0.5 mm long, inserted in the upper (½) third of the dorsal keel, usually not or rarely only slightly surpassing the glumes in A. perennans s.l. specimens from northwest South America, Central America and North America).
Agrostis subrepens, here considered to be excluded from Departamento Boyacá and possibly Colombia (see notes under 'Excluded species' A. subrepens), sometimes bears certain similar, but not equal, characteristics such as a) plants often stooling with notable pseudostolons and appearing long rhizomatous on herbarium sheets; b) culms 50−100 cm tall, slightly creeping or decumbent at their base but erect towards their apex; c) panicles open, lax, 5-10 cm wide; d) lemma unawned or awn to 0.5 mm long and straight, not twisted, inserted in the middle or upper 1/3 of the lemma or subapical; e) palea absent or < ¼ the length of the lemma. Agrostis subrepens can be differentiated from A. perennans s.l. by a) upper culm ligules 1−2.2 mm long, obtuse (vs. 3−5(−7) mm long, truncate to obtuse-triangular in A. perennans s.l.) b) leaf blades 0.5-1 mm wide in diameter as rolled or folded, convolute, involute, or conduplicate, rigid, surfaces scabrous (vs. leaf blades (1-)1.5−3.5(−5) mm wide, usually flat or conduplicate and lax to slightly firm, sometimes involute and rigid in the basal leaves, smooth throughout or scaberulous on margins and sometimes surfaces in A. perennans s.l.); anthers 1−1.3 mm long (vs. 0.7−1 mm long in A. perennans s.l.) Agrostis turrialbae, here considered to be excluded from Departamento Boyacá and possibly Colombia, bears similarities and may possibly be part of the A. perennans s.l. species complex (see notes under 'Excluded species' A. turrialbae).
Agrostis vinealis, of Eurasian origin which is not recorded for Colombia, but found introduced and naturalized in Argentina and Chile Rúgolo de Agrasar 2012), bears certain similarities (see also comments regarding this species under A. cf. imberbis). It can be differentiated by having a) lemmas usually with a persistent, geniculate and twisted awn to 4 mm long, inserted near the base (sometimes absent); b) rhizomes conspicuous, long, lateral tending, and usually covered in bracts; c) panicles contracted and rather dense before and after flowering. Many heterotypic synonyms. Description. Perennial herbs, generally creeping, usually extensively stoloniferous with long stolons to 200 cm long, less often with short stolons, rhizomes usually absent. Tillers extravaginal, with cataphylls present. Culms 15−100 cm tall, erect or decumbent at their base, delicate to fairly firm, nodes usually held within sheaths with 0(−3) exerted at flowering, usually smooth to rarely scaberulous. Leaves mainly cauline, glabrous, scaberulous; ligules 1−6.5(−8) mm long, of basal leaves and tillers 1−3 mm long, of upper culm 2−6.5(−8) mm long, rounded to truncate, not or slightly to moderately decurrent with the sheath, abaxial surface scaberulous; blades 2−26 cm long, 1−8 mm wide, flat or sometimes folded, soft and lax, surfaces and margins scaberulous to scabrous, apices acute. Panicles 2−20(−32) cm long, 1−16 cm wide, open and lax or contracted after flowering, ovoid to pyramidal, slightly to usually greatly exerted from the basal foliage, lateral branches naked in the lower 1/3−1/4 or with spikelets present to the base, long, ascending, spreading, to somewhat divergent and not held close to the central inflorescence axis at or before flowering, held close to the central rachis at maturity, central axis and panicle branches scabrous or very rarely smooth; pedicels 0.5−2.5 mm long, usually shorter than their spikelets, dilated or not at their apex, scabrous. Spikelets (not including awn, if present) 1.8−3 mm long; glumes subequal or unequal, the lower slightly longer than the upper by up to c. 0.5 mm, 1-veined, lower glume keel usually scabrous in the distal half, upper glume often smooth throughout, apices acute; floret usually 2/3−3/4 the length of the glumes; calluses with 2 sparse lateral tufts of short hairs; lemmas 1.2−2.2(−2.5) mm long, (3-) 5-veined, glabrous or rarely pubescent at the base with hairs 0.1−0.2 mm long, smooth, apex obtuse or truncate, erose, muticous or rarely with an awn 0.5−3 mm long, usually inserted above the middle of the dorsal keel, exerted or not from the glumes, straight, flexuose or geniculate, twisted or not, weak and falling easily; paleas 0.7−1.3(−1.6) mm long, (2/5−)½−¾ the length of the lemma; rachilla absent; anthers 0.9−1.6 mm long.
Distribution and ecology. Widespread and cosmopolitan or Eurasian origin, introduced to South America from Europe. While no specimens of A. stolonifera were verified from Departamento Boyacá at US or encountered during extensive fieldwork in the region, the species is cited for Boyacá in the checklist  and specimens were found at US from the neighboring Departamento Cundinamarca in the Cordillera Oriental meaning it likely that the species occurs in Boyacá.
Other specimens examined. Description. Perennial herbs, tussock-forming or laxly to densely tufted, usually with short ascending rhizomes. Tillers extravaginal and intravaginal, with cataphylls usually present. Culms (3−)5.5−51(−80) cm tall, erect or arching, fairly firm, with 0(−2) nodes exerted at flowering, smooth or rarely scaberulous. Leaves mostly basal or more-or-less evenly spread along the culm, glabrous, smooth or scabrous; ligules 2−4(−6.2) mm long, of upper culm usually longer than those of lower culm and tillers, truncate to triangular, moderately to strongly decurrent with the sheath, abaxial surface usually scabrous, rarely scaberulous or smooth; blades 2.5−19 cm long, 1−3(−5) mm wide, at least in the upper culm filiform, folded or flat, usually lax to sometimes firm, sometimes basal and tiller blades involute or convolute and firm to rigid, smooth throughout or scabrous only on the margin and sometimes veins, apices blunt or slightly naviculate-acute. Panicles (1−)2−15 cm long, 0.1−1.5 cm wide, moderately to densely congested, sub-spikelike or spikelike, sometimes interrupted towards the base, subincluded in the basal foliage or slightly to greatly exerted, lateral branches with spikelets almost to the base, upper lateral branches short and held close to the cen- tral inflorescence axis, central axis and panicle branches scabrous; pedicels 0.7−3(−4.5) mm long, usually shorter than their spikelets, not or slightly dilated at their apex, scabrous. Spikelets (not including awn, if present) 2−3(−3.6) mm long; glumes equal or subequal, 1-veined, lower glume keel and surface usually scabrous at least in the distal half, infrequently smooth throughout, upper glume keel and surface scabrous for almost their entirety to at least in the distal half or surface sometimes smooth throughout, apices acute or acuminate; floret ½−2/3(−3/4) the length of the glumes; calluses lightly pilose with 2 sparse tufts of short hairs on the lateral sides; lemmas 1.4−2.8 mm long, glabrous, smooth, 5-veined, apex truncate, denticulate, usually awned, awn 2−3.5 mm long, inserted in the lower, middle, or upper 1/3 of the dorsal keel, exerted from the glumes, geniculate, twisted, very rarely muticous or with a short straight awn, < 1 mm long, inserted in the upper half of the lemma (see notes below regarding A. glomerata); paleas absent or 0. Notes. Although in Bolivia (Renvoize 1998) and austral South America (Rúgolo de Agrasar 2012) A. tolucensis is mentioned to be notably rhizomatous, lateral tending rhizomes were not notable on specimens from the páramos of Boyacá, which had short, ascending rhizomes/pseudostolons and formed small tussocks or were laxly to densely tufted. Type specimens and original material of A. tolucensis and other species now considered synonyms of A. tolucensis, i.e. Agrostis glomerata, A. nana var. andicola, A. nana var. aristata, and A. virescens, also had either short ascending rhizomes or lacked notable rhizomes, but with all having obvious extravaginal cataphyllous shoots.
Discrepancy was sometimes also found in the form of the leaf blades, with specimens encountered in Boyacá, Colombia, and Venezuela sometimes having more rigid, convolute to folded, often recurved, basal leaf blades instead of the lax and filiform leaf blades more common to this species. These specimens did usually still have flat upper culm blades to help differentiate them from e.g. A. laegaardii (see notes on similar species below). While Renvoize (1998) and Rúgolo de Agrasar (2012) state the blades in A. tolucensis to be flat, folded, or filiform and generally lax, the type material also has fairly firm blades which are narrow and folded to slightly convolute and sometimes cylindrical in outline. Agrostis nana, here considered a synonym of A. tolucensis, also has more convolute, curved and rigid leaf blades.
Similar species. See notes under A. foliata for how to differentiate from that species. Agrostis breviculmis and A. laegaardii bear similarities in having mainly basal, narrow, usually convolute, rigid, leaf blades and densely congested spikelike panicles that are usually short (< 5 cm long), and spikelets with an absent or reduced palea < ¼ the length of the lemma. Agrostis tolucensis principally differs from these by the leaf blades being usually laxer and folded or flat, at least in the upper culm. However, as noted above, specimens can be found with convolute basal blades that makes distinguishing these species more difficult. In these instances, A. tolucensis can be differentiated from A. breviculmis by its larger spikelets 2−3(−3.6) mm long (vs. 1.5−2.1(−2.5 in Bolivia?; Renvoize 1998) mm long in A. breviculmis), usually the presence of a well-developed geniculate and twisted awn inserted dorsally usually in the lower third of the lemma (lemmas very rarely muticous or with a short straight weak awn, < 1 mm long, inserted in the upper ½; see notes on A. glomerata below) (vs. lemmas muticous or with a short straight weak awn inserted above the middle in A. breviculmis), panicles generally wider, 1−15 mm wide (vs. 0.5−2(−6) mm wide in A. breviculmis), and short prickle hairs on the glume keels (vs. coarse and shiny in A. breviculmis). While A. laegaardii has characters of often larger spikelets and dorsally inserted awn, A. tolucensis can be differentiated from A. laegaardii by its extravaginal cataphyllous shoots and distinct ascending rhizomes with rhizome internodes usually > 7 mm long (vs. purely intravaginal innovations, without cataphyllous shoots or distinct ascending rhizomes, rhizome internodes < 2 mm long in A. laegaardii), generally wider panicles, 1−15 mm wide (vs. 0.5−2(−6) mm wide in A. laegaardii), and short prickle hairs on the glume keels (vs. coarse and shiny in A. laegaardii). Specimens can sometimes have laxer inflorescences that could lead to confusion with A. mertensii, but this species does not form small tussocks.
Agrostis meyenii, a species known from drier high-elevation puna grassland and pampa of Argentina, Chile and Bolivia (Renvoize 1998; Rúgolo de Agrasar 2012), is similar in its overall appearance, usually being tufted and with rhizomes, having similar ligules and filiform or flat leaf blades, and having a condensed spikelike panicle with spikelets of similar size. Agrostis tolucensis can usually be differentiated from A. meyenii by the presence of an awn inserted in the lower third of the lemma, 2−3.5 mm long, twisted and bent and exerted from the glumes (vs. muticous or, if awn present, inserted in the middle or upper third of the lemma, to 1.2 mm long, straight or slightly flexuous in A. meyenii). However, specimens akin to A. glomerata, a species described from Peru and here considered a synonym of A. tolucensis, can sometimes be found in Colombia, albeit not in the Cordillera Oriental, which have muticous lemmas or with a short straight awn inserted in the upper half of the lemma (e.g. Idrobo 3882a, Mutis 5521). These can be differentiated from A. meyenii by the plants being generally taller, 20−60 cm tall, condensed panicles often > 10 cm long that are often interrupted and with the central inflorescence axis notably wider compared to the lateral branches, and the pedicels, panicle branches, and sometimes central inflorescence axis, being notably scabrous. The blades of these are variable and can be filiform to flat and to 5 mm wide. The characteristic of notably scabrous pedicels, panicle branches, and sometimes central inflorescence axis of A. tolucensis are considered to be key in differentiating these from A. meyenii, which are usually smooth or exceptionally lightly scaberulous. Description. Perennials. Leaves mainly basal; ligules membranous. Inflorescence a panicle, lax and open to contracted and spikelike. Spikelets 1-flowered, disarticulating above the glumes, laterally compressed; glumes as long as the spikelet, equal or subequal, persisting on the plant after the florets have fallen; lower glume 1-or 3-veined; upper glume 1-(2-) or 3-veined; floret subequalling to equaling the apex of the glumes; lemmas membranaceous, often slightly thicker than the glumes, dorsally rounded, 3-or 5-veined, lateral veins not evident to distinct; paleas well-developed, reaching from (2/3) ¾ to subequaling the lemma, keels obscure to distinct, glabrous, usually smooth; calluses rounded, blunt, usually glabrous, or with two short lateral tufts of hairs to 0.5 mm long in some species, abaxially smooth; rachilla prolongation present, varying from rudimentary to 2/3 the floret in length, glabrous or sometimes with short strict hairs to 0.3 mm long emerging only from the apex, smooth or scaberulous. Flowers perfect; anthers 3 in number, 0.4-2.2 mm long. Caryopses hard. Description. Perennial herbs, forming short dense tufts, with the basal mats reaching c. 4-11 cm tall and inflorescences well-exerted from the basal foliage. Tillers intravaginal, without cataphylls. Culms 7-20(-30) cm tall, erect, simple, delicate, with 0(−1) nodes exerted at flowering, smooth. Leaves mostly basal, glabrous, finely to densely scabrous; ligules 0.7-1.7(-2.5) mm long, of basal leaves and tillers 0.7-1.2 mm long, of upper culm leaves generally longer, truncate to obtuse, slightly to usually strongly decurrent with the sheath, abaxial surface smooth or rarely scaberulous; blades 1-4 cm long, 0.3-0.4 mm wide in diameter, involute or convolute, acicular to capillaceous and filiform, usually curved, rigid, apices acute. Panicles 2-5(-6) cm long, 1-2(-3) cm wide, lax and open, ovoid, slightly to usually greatly exerted from the basal foliage, lateral branches with spikelets in the distal 1/3, the lower 2/3 naked, long, ascending to patent, not held close to the central inflorescence axis, central axis and panicle branches usually scaberulous or sometimes smooth; pedicels 1-2 mm long, usually longer than the length of the spikelets, not or slightly dilated at their apex, smooth to usually lightly scabrous. Spikelets 1-1.5 mm long; glumes equal or subequal, the lower often slightly longer than the upper, 1-veined, keels scabrous just in the distal 1/3 to throughout their length, surfaces smooth a scabrous distally, apices obtuse to acute; floret almost equaling the length of the glumes or slightly shorter; calluses glabrous; lemmas 1-1.5 mm long, glabrous, moderately to densely scabrous ('smooth' possibly mentioned by Tovar 1993!), sometimes granulose, apex obtuse, faintly to strongly 5-veined, awn lacking or to 0.5 mm long, straight, inserted medially or in the upper half of the lemma, not surpassing the glumes; paleas (0.7-)0.9-1.3 mm long, usually reaching from ¾ to subequaling the lemma, less often reaching 2/3 the length of the lemma; rachilla usually prolonged from the base of the floret (sometimes lacking in a small number of spikelets within the inflorescence), 0.2-0.5 mm long, glabrous, smooth to scabrous; anthers 0.4-1 mm long. Distribution and ecology. Colombia, Ecuador?, Peru, Venezuela, 2800-4500 m alt. Relatively humid high-Andean puna grasslands of southern and central Peru and páramo grasslands of Ecuador, Colombia and Venezuela. May also occur in Bolivia according to Tovar (1993), although no specimens have been verified. No specimens have been verified from Ecuador, although it is mentioned to occur there (Hitchcock 1927;Tovar 1993;Jørgensen and Ulloa-Ulloa 1994;Jørgensen and León-Yánez 1999;Luteyn 1999). A common element in moderately grazed areas and path-sides of Boyacán páramo.

Notes.
The combination of open panicle, spikelets < 1.5 mm long, florets which subequal the apex of the glumes, a palea reaching from (2/3) ¾ to subequaling the lemma, lemmas awnless or with a short (< 0.5 mm long) straight awn inserted in the upper ½ of the lemma, and a short glabrous rachilla prolongation emerging from under the palea are diagnostic for this species. The rachilla prolongation (Fig. 11, indicated by arrows) is sometimes difficult to see if it is tucked between the flanges of the palea, and so spikelet dissection is necessary. All species of Podagrostis from Colombia have involute or convolute leaf blades that can easily separate them from species of Agrostis with well-developed paleas.
Similar species. Aside from Podagrostis bacillata (Hack.) Sylvester & Soreng and P. exserta (Swallen) Sylvester & Soreng that are found in Central America (see Sylvester et al. 2020), P. trichodes could possibly be mistaken for shorter plants of A. perennans which can have short spikelets as small as 1.8 mm long. Agrostis perennans s.l. has florets which usually do not reach past ¾ the length of the glumes, a minute palea less than ¼ the length of the lemma, and lacks a rachilla prolongation. scabrous leaf blades while A. mertensii is generally smooth or only scaberulous in the leaf blade adaxial surface and margin. The leaf blades are also mentioned to be stiff and erect while those of A. mertensii are generally lax and soft.
Agrostis subrepens (Hitchc.) Hitchc., N. Amer. Fl. 17 (7) Venezuela. Sin loc., no date, Fendler 2541 (US843224). Notes. Ambiguity surrounds the identity and placement of A. subrepens. Hitchcock (1905) initially described this as a variety of A. hyemalis (Walter) Britton, Sterns & Poggenb., but then raised it to the level of species 32 years later. Originally stated to occur in northern Mexico, and the states New Mexico, Nevada, Arizona of the USA, and Venezuela (Hitchcock 1905), in his later account, Hitchcock (1937) then restricts the distribution to wet places of the Sierra Madre, Chihuahua, Mexico, and also Venezuela based on the specimen Fendler 2541 (US843224). This Venezuelan paratype was seen by us at US but only comprised two fragments of an inflorescence and no leaves. As both A. perennans and A. subrepens have strikingly similar spikelet morphology, there was no way to be confident on its placement, raising ambiguity over whether A. subrepens occurs in South America. The species has been included in checklists or taxonomic treatments for Bolivia (Jørgensen et al. 2014), Colombia (Giraldo-Cañas et al. 2016, Peru (Tovar 1993), and Venezuela ). The identification key and description of A. subrepens in the treatment for Peru (Tovar 1993) do not match the type specimens and it may be that Tovar (1993) had not seen types as he distinguishes this from A. perennans (sub A. humboldtiana) and A. imberbis (sub A. stenophylla) in part by the leaf blades being flat and flaccid. Although Giraldo-Cañas et al. (2016) mention this species to occur in Departamentos Boyacá, Cundinamarca, and Santander of the Cordillera Oriental, and Antioquia, Huila, and Quindio of the Cordillera Central, no specimens have been verified by us, although we did not revise specimens outside of Boyacá while at COL and none were verified from these provinces while at US. While we have found certain characteristics to differentiate this from A. imberbis, such as culm paleas are absent, but this character appears to be too variable to be useful. Discrepancy in spikelet size is also apparent, with the A. turrialbae protologue stating 1.75 mm long and the A. vesca protologue stating 1.6−1.8 mm long, while all other publications describing the species Pohl and Davidse 1994;Morales-Quirós 2003) state 2−2.1 mm or 2−2.8 mm long.
We here tentatively differentiate the two species by A. turrialbae having leaf blades filiform, 0.2−1 mm wide when opened out, thin and flaccid, leaves mainly basal at maturity, and plants generally smaller with culms to 40 cm tall and panicles to 12 cm long and 6 cm wide (vs. leaf blades flat or conduplicate, (1-)1.5-6 mm wide when opened out, rarely involute in the basal leaves, usually thickened at the margins and keel, firm, leaves mainly basal early in the flowering season but tending to become mostly cauline with maturity, and plants generally larger, with culms to 100 cm tall and panicles often larger, to 22 cm long and 11 cm wide in A. perennans s.l.). No specimens of A. turrialbae that fit this delineation have been found at US from either Colombia or Venezuela. Furthermore, A. turrialbae may be better included among the broad A. perennans complex until a satisfactory revision can be done of this species complex, which has been found to comprise evolutionarily distinct lineages in unpublished molecular phylogenies (Konstantin Romaschenko, pers. communication).