Research Article |
Corresponding author: Mihai Costea ( mcostea@wlu.ca ) Academic editor: Sandy Knapp
© 2021 Mihai Costea, Simone Soares da Silva, Rosangela Simao-Bianchini, Ana Rita G. Simoes, Sasa Stefanovic.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Costea M, Soares da Silva S, Simao-Bianchini R, Simoes ARG, Stefanovic S (2021) Notes on the systematics of Cuscuta sect. Subulatae (subg. Grammica) with the description of Cuscuta mantiqueirana, a new species from Brazil. PhytoKeys 184: 27-44. https://doi.org/10.3897/phytokeys.184.69037
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Cuscuta mantiqueirana Costea, S.S. Silva & Sim.-Bianch. a new species from montane cloud forests of the Serra da Mantiqueira, Brazil, is described and illustrated. The morphological and phylogenetic analyses revealed that the new species belongs to sect. Subulatae subg. Grammica. The new species is related to C. odorata var. botryoides, C. rotundiflora and C. globiflora from which it differs in narrower calyx lobes and the presence of four stomatiferous lobes or projections at the distal part of the ovary. A detailed morphological comparison with C. odorata var. botryoides, morphologically the most similar taxon, is provided along with the geographical distribution, ecology and host range of the species. The morphological and phylogenetic relationships of the new species, as well as the diversity of stomatiferous projections, are discussed in the broader context of sect. Subulatae and subg. Grammica. Cuscuta boliviana var. paranensis is considered a synonym of C. odorata var. botryoides.
Convolvulaceae, dodders, ITS, morphology, parasitic plant, phylogeny, systematics
With ca. 30 species, Cuscuta sect. Subulatae (Engelm.) Costea & Stefanović is the largest infrageneric group of subg. Grammica (Lour.) Peter, and of Cuscuta L. in general (
The objective of this study is to report a new species in sect. Subulatae, as well as to discuss its putative relationships with other taxa in this group. The new species has been discovered independently both among herbarium specimens and by doing field work.
Cuscuta specimens from the following herbaria were examined and annotated: AAU, B, BAB, BM, BR, BRIT, CAS, CEN, CORD, CTES, DAO, DIAM, E, ESA, F, G, GH, HB, HRCB, HUEFS, HUFU, HUSC, IAC, JEPS, K, L, LIL, LP, LPB, LPS, MA, MBM, MEL, MERL, MEXU, MICH, MO, NY, OXF, P, PACA, PMSP, QCNE, R, RB, RSA, S, SGO, SI, SJRP, SP, SPF, SPSF, TEX, TRTE, UB, UCR, UEC, UPCB, UPRRP, UPS, US, W, and WLU (Herbaria acronyms from
Of the 28 collections of individuals belonging to the new species C. mantiqueirana, three specimens (Appendix
Phylogenetic analyses were conducted under parsimony and maximum likelihood using PAUP* v4.0b10 (
Flowers, fruits and seeds removed from herbarium specimens were steeped in gradually warmed 50% ethanol, which was then allowed to boil for a few seconds to rehydrate tissues. An ethanol solution is more suitable for rehydration than simple water because it removes some of the dark pigments that result after drying, and at the same time, it hardens the tissues, which are very delicate in the Cuscuta flowers. For basic morphology, flowers were dissected under a Nikon SMZ 1500 stereomicroscope and imaged with PaxCam Arc digital camera equipped with a PAX-IT 8.2 (MIS Inc. 2021, Villa Park, Illinois) imaging software. Numerous photographs illustrating details of the floral and fruit morphology for all taxa, including their type collections, are made available on the Digital Atlas of Cuscuta website (
The parsimony analysis resulted in 12 MP trees [length = 161; consistency index (CI) = 0.907; retention index (RI) = 0.957]. The maximum likelihood analysis resulted in a single ML tree, topologically fully compatible with the strict consensus of the MP trees. The ML phylogeny was selected to illustrate the inferred relationships in this section, including the placement of C. mantiqueirana, as well as branch lengths (Fig.
Phylogenetic relationships among species of Cuscuta sect. Subulatae shown as a phylogram obtained from maximum likelihood analysis of nrITS sequence data under the GTA+G+I model of DNA evolution. Tree is rooted using C. microstyla as a functional outgroup. Numbers following species names correspond to DNA accessions (Appendix
Cuscuta microstyla formed a distinct lineage within sect. Subulatae (Fig.
1 | Infrastaminal scales with densely papillate fimbriae | (Clade A) |
– | Infrastaminal scales without papillae on fimbriae or only with a few distal papillae (scales sometimes absent in C. kilimanjari) | 2 (Clade B) |
2 | Corolla tubular-cylindrical becomes tubular-urceolate at fructification | C. parodiana |
– | Corolla rotate or campanulate becomes globose to urceolate-globose at fructification | 3 |
3 | Corolla membranous, rotate | C. friesii , C. argentinana |
– | Corolla fleshy, campanulate becomes globose to urceolate-globose at fructification | 4 |
4 | Fruit indehiscent to late irregularly-dehiscent | C. cristata |
– | Fruit circumscissile dehiscent | 5 |
5 | Infrastaminal scales absent or with a few fimbriae; Africa | C. kilimanjari |
– | Infrastaminal scales well developed with numerous fimbriae; South America | 6 |
6 | Corolla lobes erect-connivent; stigmas conical | C. globiflora |
– | Corolla lobes spreading or reflexed; stigmas globose or depressed | 7 |
7 | Stamen filaments and styles evidently subulate; stigmas 1–1.5 mm wide | C. rotundiflora |
– | Stamen filaments and styles cylindrical or only slightly subulate; stigmas 0.3–0.7 mm wide | 8 |
8 | Pedicels obconical; flowers (4–) 5–7 mm long; external calyx lobes usually not carinate; capsule with a collar around the interstylar aperture | C. mantiqueirana |
– | Pedicels cylindrical; flowers 3.8–5 mm long; external calyx lobes carinate; capsule without a collar around the interstylar aperture | C. odorata var. botryoides (= C. boliviana var. paranensis) |
Cuscuta mantiqueirana is similar to C. odorata var. botryoides, C. rotundiflora and C. globiflora because of their corolla that becomes globose at fructification and their well-developed scales with numerous fimbriae, but it differs from all these taxa in narrower calyx lobes, the presence of four stomatiferous lobes or projections, 0.4–0.6 mm long at the ovary apex, which form a collar at the fruit stage, as well as 3-colpate pollen grains with reticulate tectum. It differs from C. odorata var. botryoides in the obconical pedicels and larger flowers, 4.5–7 mm long (pedicels are cylindrical and flowers 5.5–5 mm long in C. odorata var. botryoides). From C. rotundiflora it differs in the infrastaminal scales equalling or exceeding the corolla tube, cylindrical stamen filaments and styles, as well as stigmas 0.5–0.6 mm wide (in C. rotundiflora the scales are shorter than corolla tube, filaments and styles are subulate and stigmas 1–1.5 mm wide. From C. globiflora it differs in the spreading to reflexed corolla lobes and globose-depressed stigmas (in C. globiflora, corolla lobes are erect-connivent and stigmas conical).
Brazil. Minas Gerais: Camanducaia, Monte Verde. Parasita com ramos desde alaranjados até vináceos, sempre em local sombreado e humido. Flores amarelas, 22 IV 1999, R. Simão-Bianchini 1241 (holotype: SP!; isotypes: K!, NY!, MBM!, R!, SPF!, UB n.v., UEC!, WLU!)
Stems medium to coarse, yellow-orange, purple-tinged or entirely purple. Inflorescences paniculiform-racemiform, occasionally glomerulate, usually not confluent; pedicels 1.5–4 mm, thick, gradually tapering into the fleshy, conical receptacle; bracts 1 at the base of cymes, 1.1–2.5 mm long and 0.8–1.6 mm wide, fleshy, triangular-ovate, rounded, not carinate, margins entire. Flowers 5-merous, (4–) 5–7 mm long, fleshy, white when fresh, dark-brown when dried; papillae absent; laticifers ± visible, translucent in the calyx, corolla lobes, and more noticeable, dark-colored in the 1/3 distal half of the ovary; isolated, oblong-ovoid. A few stomata are present along the calyx mid-vein lobes, but stomatiferous carinas are usually absent; calyx 2.8–4 mm long, creamy-white to purple-tinged when fresh, dark-brown when dried, not reticulate, dull, cupulate, ca. 3/4 as long as corolla tube, divided 2/3–4/5 to the base, tube 0.5–1.5 mm long, lobes 2–2.5 mm long, ovate-oblong, longer than wide to as long as wide, the two external ones overlapping, usually not carinate, margins membranous, finely erose, not auriculate at base, apex rounded; corolla (4–) 4.5–7 mm long, tube 2.1–4.6 mm long, campanulate but becoming ± globose at fructification; lobes 1.8–2.5 mm long, initially erect, later reflexed, shorter than the tube, broadly ovate, overlapping, ± auriculate at base, margin entire to irregularly crenulate, apex rounded, straight; stamens exserted, shorter than the corolla lobes, anthers 0.8–1.2 mm long, elliptic to oblong, filaments 0.6–0.8 mm long; pollen 3-zonocolpate,19–29.5 μm long and 17–20 μm wide, subprolate to spheroidal or suboblate, tectum microreticulate to reticulate, lumina 0.9–3.3 μm in diameter; infrastaminal scales 3–5 mm long, equalling to slightly longer than corolla tube, ovate to oblong, bridged at 0.7–1.6 mm, densely fimbriatae, fimbriae 50–80, 0.5–1.2 mm long, thin-filiform without papillae distally; ovary apex on both sides of styles raised to form two pairs of lobes or projections with stomata, 0.4–0.6 mm long; styles 0.3–0.9 mm long, 0.3–0.5 mm thick, much shorter than the ovary, cylindrical to slightly subulate, sometimes also with stomata at their base; stigma 0.35–0.6 mm long and 0.5–0.7 mm wide, white to purple in the fresh flowers, globose to wider than long, convoluted and lobed. Capsules circumscissile, 4–4.8 mm long and 4–5.5 wide mm, globose to ovoid, with a collar around the large interstylar aperture, opaque, entirely surrounded by the withered, persistent corolla. Seeds 2 per capsule, 1.5–2.8 mm long and 2–2.4 mm wide, dorsiventrally compressed, subrotund, hilum area lateral, 0.7–1 mm in diameter, scar 0.25–0.30 mm long, seed coat alveolate/papillate. Chromosome number not known.
Comparative morphology of Cuscuta mantiqueirana and C. odorata var. botryoides using rehydrated herbarium material A–M Cuscuta mantiqueirana A inflorescence B incipient stage of inflorescence development showing bract and developing flowers C flower and bract D calyx 3D, note the receptacle prolonging into obconical pedicel E, F calyx dissected, variation G corolla 3D H corolla dissected to show infrastaminal scales and stamens I stoma on calyx lobe, note that large protuberances with stomata do not develop in this species J distal part of infrastaminal scale K detail of infrastaminal scale fimbriae, note that no papillae are present L gynoecium M detail of distal part of ovary showing 4 lobes with stomata flanking the two styles. All images were obtained from G.F. Árbocz et al. 2750 except A, B, H and L which are from the type, Simão-Bianchini 1241 N–W Cuscuta odorata var. botryoides N flower O calyces 3D P calyx dissected, note the broader calyx lobes, two of them with prominent carinas that bear stomata (indicated by arrows) R detail of carinate calyx lobe S corolla 3D T fragment of dissected corolla U infrastaminal scales V detail of fimbriae showing 1–2 papillae at their tips (arrows) W1 gynoecium W2 detail of distal part of ovary, note the absence of lobes with stomata. All images from Lobb 49 except P, R = Hatschbach 22109 and V = Hoehne s.n. Scale bars: 1 mm (A–H, L, N–Q, S–U, W1, W2); 50 μm (I); 0.5 mm (J, M, R, K); 0.25 mm (V).
Morphological comparison between C. mantiqueirana and C. odorata var. botryoides.
Character | Cuscuta mantiqueirana | Cuscuta odorata var. botryoides |
---|---|---|
Stems | Yellow-orange, purple-tinged or purple | Yellow-orange |
Pedicels | 1.5–4 mm, obconical | 1–3 mm, cylindrical |
Bracts | 1.1–2.5 mm long | 2.2–3.2 mm long |
Flower length | (4–) 5–7 mm | 3.8–5 mm |
Calyx | 2.8–4 mm long, divided 2/3–4/5 to the base, tube 0.5–1.5 mm long, lobes 2–2.5 mm long, ovate-oblong, longer than wide to as long as wide, the two external ones overlapping, usually not carinate, not auriculate at base. | 2.8–3.4 mm long, divided ca. 1/2–2/3 to the base, tube 1–2 mm, lobes ovate-round, 1–2 mm long, wider than long, the two external ones carinate, broadly overlapping, auriculate at base. |
Corolla | (4–) 4.5–7 mm long, tube 2.1–4.6 mm long, lobes 1.8–2.5 mm long. | Corolla 3.5–4.5; tube 2–3.5 mm long, lobes 1–1.8 mm long. |
Infrastaminal scales | 3–5 mm long, bridged at 0.7–1.6 mm, fimbriae 50–90, 0.5–1.2 mm long, thin-filiform without papillae. | 2–3.7 mm long, bridged at 1–1.5 mm, fimbriae 60–110, 0.3–0.6 mm, often with 1–2 distal papillae. |
Stamens | Anthers 0.8–1.2 mm long, filaments 0.6–0.8 mm long. | Anthers 0.6–0.8 mm long, filaments 0.4–0.6 mm long. |
Pollen | 3-zonocolpate,19–29.5 μm long and 17–20 μm wide, subprolate to spheroidal or suboblate, tectum microreticulate to reticulate, lumina 0.9–3.3 μm in diameter. | (3–) 4–5 colpate, 19–26 μm long and 18–26 μm wide, sphaeroidal to subsphaeroidal, tectum perforatum; puncta 0.4–1(1.2) μm in diameter. |
Ovary | Ovary apex on both sides of styles risen to form 4 lobes or projections with stomata, 0.4–0.6 mm long. | Apex without lobes or projections but a few stomata may be present. |
Styles and stigmas | Styles 0.3–0.9 mm long, 0.25–0.5 mm thick, cylindrical or slightly subulate, sometimes also with stomata at their base; stigmas 0.35–0.5 mm long and 0.5–0.7 mm wide | Styles 0.8–3 mm long, 0.25–0.35 mm thick, cylindrical; stigmas 0.3–0.4 mm long and 0.3–0.5 mm wide. |
Capsule | Stomatiferous lobes form a collar around the large interstylar aperture | Without a collar around the large interstylar aperture. |
Distribution | Brazil: Minas Gerais, Rio de Janeiro and São Paulo. | Argentina: Misiones; Brazil: Paraná, Santa Catarina. |
Elevation | 800–2360 m | 3–150 m |
Ecology | Montane rain forest | Resting in a forest or near rivers |
The new species is apparently endemic to Serra da Mantiqueira in Southeastern Brazil (states of Minas Gerais, Rio de Janeiro and São Paulo), where it occurs at elevations between 800–2360 m. The climate is mesothermic, characterized by distinct dry and rainy seasons, with an average temperature that depends on the elevation, but generally exceeding 10 °C (
Micromorphology of Cuscuta mantiqueirana and C. odorata var. botryoides A–G Cuscuta mantiqueirana A distal part of ovary B stomata on lobes flanking styles C stomata (indicated by arrows) at the base of styles D–E infrastaminal scale fimbriae and detail F–G 3-colpate, reticulate pollen. All images from G.F. Árbocz et al. 2750 except C which is from Simão-Bianchini 1241 H–K Cuscuta odorata var. botryoides H gynoecium I–K pollen grain: 5-colpate with perforate tectum. All images from Burkhart 1626. Scale bars: 0.5 mm (A); 100 μm (B–D); 50 μm (E); 10 μm (F, I); 1 mm (H); 5 μm (G, J, K).
Flowering in Nov-Dec and Feb-Aug, which may depend on the elevation. Very few herbarium specimens possess capsules and seeds which suggests that plants are preponderantly xenogamous and also reproducing vegetatively (
Habitat, habit, inflorescences and flowers of living Cuscuta mantiqueirana A, B montane cloud forest habitat (arrows indicate C. mantiqueirana) C, D habit E the most common host, Fuchsia regia F–H inflorescences I flowers (F–I photos: Suzana Ehlin Martins F, H Itatiaia G, I Serra do Papagaio).
The specific epithet is a feminine adjective that comes from the name of the mountain range to which the species is apparently endemic. The word “Mantiqueira” is derived from Tupi-Guarani meaning “mountains that cry” alluding perhaps to the plethora of dripping water, streams and rivers that are present during the wet season with abundant rainfall (
The common names used in the area are: Cipó-chumbo, fios-de-ovos, erva-de-passarinho (although also commonly used for other species of Cuscuta that occur in the region).
The GeoCAT rapid assessment tool (
Brazil. Rio de Janeiro: Itatiaia, 13 Apr 1963, E. Pereira & C. Pereira 7559 (HB); idem, Km 7 da estrada de Registro para Planalto, 17 Feb 1969, G.F.J. Pabst 9306 (MBM, HB); Parque Nacional de Itatiaia, 2 Nov 1965, G.G. Eiten & L.T. Eiten 6528 (SP); idem, 2 Apr 1960, O.M. Barth 7144 (IOC, US); idem Pico das Agulhas Negras, 2159 m, 1 May 1977, D.M. Vital s.n. (UEC, BR, NY); idem, Estrada Nova Km 8, 25 Mar 1942, A.C. Brade 17266 (RB); idem, 2200 m, 1 May 1977, J. Vasconcellos-Neto et al. s.n. (UEC); Estrada do Ponto Zero para as prateleiras, 22°22'12"S, 44°42'31"W, 2380 m, 11 Dec 2002, R. Marquete et al. 3437 (RB; DNA accession 1123); Resende, West side of Mt. Itaiaia, at km 9–10 km on road from “Registro” to the shelter house, “Abrigo Rebouças”, 2100 m, 7 Nov 1965, G.G. Eiten & L.T. Eiten 6682 (K, SP, NY, MO, UBC, US); Estrada vicinal de acesso ao Pico das Agulhas Negras, 24 May 1996, G.F. Árbocz 2750 et al. (SP, NY, UEC, WLU). Minas Gerais: Alto Caparaó, Parque Nacional do Caparaó, Trilha Tronqueira ao Pico da Bandeira, 13 Mar 2010, J.M. Silva & J. Cordeiro 7543 (MBM); Camanducaia, Monte Verde; idem, 3 Jun 1992, R. Simão-Bianchini 317 (SPF, WLU); idem, 12 Jan 2020, R. Simão-Bianchini 2332 (SP); idem, 16 Mar 1976, H.F. Leitão Filho et al. 1815 (UEC, SPSF, UB, WLU) idem, Serra da Mantiqueira, 11 Dec 2001, L.D. Meireles & R. Balinello 770 (UEC); idem, Pico do Selado, 1810 m, 17 May 2002, L.S. Kinoshita et al. 72 (UEC); Itamonte, Parque Nacional do Itatiaia, 20 Nov 2018, S.S. Silva et al. Itati 02, 04, 05 (SP, WLU); idem, 21 Nov 2018, S.S. Silva et al. Itati 08 (SP, WLU; DNA accession 2436); idem, Itamonte, Serra Fina, Sítio Pierre, 2100 m, 20 Jul 2005, L.D. Meireles et al. 1843 (SP, UEC); Idem, 4 Apr 1995, 2100 m, I. Koch & L.S. Kinoshita 449 (UEC); São Paulo: Campos do Jordão, Instituto Kurihara, 8 Jun 1940, G. Hashimoto 262 (SP); idem, Parque Estadual Campos do Jordão, 1760 m, 8 Feb 1980, R.A.A. Barreto 48 (SPSF); idem, Praia São José dos Alpes, 8 Jun 1992, E. Gianotti et al. 26667 (UEC); idem, 2 Aug 1980, A.A.B. Rubens 48 (RB) Pindamonhangaba, P.E. de Campos do Jordão, 12 Apr 1985, M.J. Robim 277 (SPSF); idem, 12 Apr 1985, C. Proença & M.F. Bean 496 (CEN, UB).
Cuscuta odorata var. boliviana Engelm. Trans. Acad. Sci. St. Louis 1: 477. 1859.
= C. boliviana var. paranensis Hunz., Revista Argent. Agron. 14: 142.1947.
The morphological distinctiveness of C. mantiqueirana allows its unequivocal recognition as a new species even though we could not obtain molecular data for some morphologically similar taxa – C. rotundiflora and C. odorata var. botryoides. The available molecular results agree with the morphological patterns observed in section Subulatae, and the similarity of C. mantiqueirana, C. odorata var. botryoides, and C. rotundiflora strongly suggests a phylogenetic proximity of these taxa in clade B (Fig.
As indicated, C. mantiqueirana is most similar morphologically to C. odorata var. botryoides (Table
Stomatiferous structures have been recently documented in many Cuscuta species (reviewed by
Argentina. Type of C. boliviana var. paranensis; Missiones, Posadas, en la costa del río, 15 Jul 1945, Bertoni 1502 (LIL); idem, 2 Aug 1945, Burkhart 1626 (CORD). Brazil. Type of C. odorata var. botryoides; “S. Brasil”, Lobb 49 (K, MO); Paraná: Mun. Paranagua, Ipanema, 27 Aug 1969, 3–5 m, Hatschbach 22109 (K, MBM, MO); paratype of C. boliviana var. paranensis; idem, 25 Oct 1929, Hoehne s.n. (SP 24476).
We thank the curators/directors of the cited herbaria for making the specimens available for study. John Wood and Sandy Knapp provided thoughtful comments that greatly improved the quality of the article. Suzana Ehlin Martins kindly allowed the use of C. mantiqueirana photographs taken in the field. Ulisses G. Fernades, Fátima O.S. Buturi and Sônia Aragaki helped with the identification of the hosts. This research was supported by NSERC of Canada Discovery grants to M. Costea (327013), S. Stefanović (326439), S.S. Silva (Research grant CAPES numbers 88882.444239/2019-01 and 88887.595917/2020-00) and CNPq grants to R. Simão Bianchini (311738/2016-8).
Taxa, DNA accession numbers, sources of plant material from which DNA was extracted, and GenBank accession numbers for nrITS sequences used in this study. Extraction numbers following species names are indicated on the phylogenetic tree (Fig.
Cuscuta aff. chilensis Ker Gawl.: 999, Hichins & Muñoz s.n. (SGO), EF194525; 1000, Teiller et al 2489 (SGO), EF194524; C. chilensis: 567, Ledingham 4455 (USAS), EF194520; 715, Arroyo et al. 996099 (SGO), EF194521; 716, Morales and Cordoba s.n. (SGO), EF194522; 967, Landrum 3392 (ASU), EF194523; 985, Muñoz and Meza 2202 (SGO), EF194519; C. cockerellii Yunck.: 1055, Straw 2267 (US), EF194518; C. cristata Engelm.: 939, Riggs 100 (F), EF194529; 1026, Landrum 3057 (ASU), EF194531; 1045, Hunziker 5047 (US), EF194530; C. foetida (var. foetida) Kunth: 496, Ollgaard & Balsev 8960 (F), EF194512; 922, Steyermark 53255 (F), EF194513; 1020, Sparre 16952 (TEX), EF194511; C. foetida var. pycnantha (Benth.) Yunck.: 990, Lira 13 (SGO), EF194527; C. friesii Yunck.: 1076, Cabrera et al. 21399 (LP), EF194536; C. globiflora Engelm.: 909, Vargas 684 (F), EF194533; 926, Buchtien 133 (F), EF194534; C. grandiflora Kunth: 540, Hutchinson & Wright 4305 (F), EF194535; C. kilimanjari Oliv.: 471, Knox 5020 (TRTE, IND), EF194528; C. mantiqueirana Costea, S.S. Silva, Sim.-Bianch., sp. nov.: 1123, Marquete 3437 (RB), MZ389691; 2436, Silva et al. 08 (SP/WLU), MZ389690; 2437, Simão-Bianchini 1241 (SP/WLU), MZ389689; C. microstyla Engelm.: 707, Muñoz et al. 3575 (SGO), EF194538; 987, Vargas & Farah 80 (SGO), EF194537; C. odorata var. odorata: 912, Hutchinson 1055 (F), EF194514; 1024, Asplund 7737 (TEX/LL), EF194515; C. paitana Yunck.: 940, Haught 63 (F), EF194516; 941, Weberbauer 7762 (F), EF194517; C. parodiana Yunck.: 512, Krapovickas 37354 (F), EF194532; C. purpurata Phil.: 1432, Muñoz 5132 (SGO/WLU), MZ389688.