Monographs Details: Rhynchospora velutina (Kunth) Boeckeler
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Cyperaceae
Description:Distribution and Ecology - Distribution. Widely spread from Mexico and the West Indian Islands through Central America, lowland Colombia, Venezuela, and the Guianas southwards to southern Brazil and northern Argentina. The following are the specimens examined from South America. COLOMBIA. Villavicencio, Intendencia Meta, 450 m alt, Pennell 1620 (NY). VENEZUELA. Zulia: Kuanua, Teite, Gines 1314 (MAR). Bolívar: Hato La Vergareña, W side of Caño Azul, near rice barn, 390 m alt, Wuradack 370 (NY). Amazonas: Esmeralda, 325 ft alt, Tate 243 (NY), Esmeralda, Croizat 181 (NY). GUYANA. [Without details,] Jenman 6129 (K, NY), Schomburgk 667 & 711 (K). BRAZIL. Amapá: vicinity of Igarapé Ariramba, Pires & Cavalcante 52331 (IAN, NY). Amazonas: Rio Branco, Parime, Serra de Paracaima, Ule 8072 (B); Rio Cotin Contá, Luetzelburg 20988 (M, R); Rio Madeira, Road Humaitá to Labrea at Km 20. Prance et al 3379 (IAN, NY). Minas Gerais: Rio S. Francisco, Martius (M); Serra do Espinhaço, 35 km NE of Francisco Sa., road to Salinas, 1100 m alt, Irwin et al 23232 (NY, UB). Goiás margin of Rio Corumba, 50 km from Luiziania, Heringer & Lima 11714 (NY, UB); Serra Geral de Goiás, Rio da Prata, ca 6 km S of Posse, 800 m alt, Irwin et al 14403 (NY); Tiradentes, Duarte 3547 (NY, RB), João Pinheiro, Heringer 8546 (HB, NY). Mato Grosso: Cataqui-iamám, Kuhlmann 1908 (NY, RB). São Paulo: Villa Emma, Brade 12155 (B, R); 3.7 km NNW of Padua Sales, municipio de Moji Guaçu, 575-625 m alt, Eiten & Eiten 2711 & 2709 (NY). Paraná: Ponta Grossa, Dusén 2455 (P, NY); Villa Velha near Ponta Grossa, Höhne 23380 (SP). BOLIVIA. Oriente: Lago Rogagua, 1000 ft alt, Rusby 1425 (NY). Santa Cruz: Buena Vista in Prov. Sara, Steinbach 5335 & 5337 (NY). PARAGUAY. Northern Paraguay, region of Río Apa, Hassler 8078 & 8253 (NY); Central Cordillera: Cerros de Tobaty, Hassler 6394 (NY). ARGENTINA. Misiones: Posadas, near La Granja, Ekman 1261 (NY, S), Santiago, Estancia La Soledad, Pedersen 4394 (C, NY); Corrientes: Mburucuyá, Estancia Santa Teresa, Pedersen 4428 (C, NY, SI).

Discussion:

Fig 16.

Dichromena velutina Kunth, Enum. PI. 2: 282. 1837. Type. Sellow (B) from “Brasilia meridionalis.”

[Schoenus velutinus Schrader ex Kunth, Enum. PI. 2: 282. 1837. Invalid name published as a synonym.]

Dichromena sellowiana Kunth, Enum. Pl. 2: 282. 1837. Type. Sellow (B) from “Brasilia meridionalis.”

Psilocarya velutina (Kunth) Nees, Fl. Brasil. 2(1): US, t. 7. 1842. Based on Dichromena velutina Kunth.

[Schoenus mollis Schrader ex Nees, Fl. Brasil. 2(1): US. 1842. Invalid name published as a synonym.]

[Pachymitra velutina (Kunth) Nees, Fl. Brasil. 2(1): 115. 1842. Invalid name published as a synonym.]

Psilocarya pohlii Nees, Fl. Brasil. 2(1): 115. 1842. Syntype. Pohl 73 & 1179 (W) from Serra dos Cristaes et montibus Claris, prov. Goyazanae, Brazil. Syn nov.

Psilocarya divergens Nees, Fl. Brasil. 2(1): 116. 1842. Type. Martius (M) from “deserto fluminis S. Francisci prov. Minarum,” Minas Gerais, Brazil. Syn nov.

Psilocarya sellowiana (Kunth) Nees, Fl. Brasil. 2(1): 117. 1842. As “selloviana.” Based on Dichromena sellowiana Kunth.

Psilocarya rufa Nees, FI. Brasil. 2(1): 117. 1842. Type. Pohl 781 (W) from “fluvio S. Marco prov. Goyazanae,” Goiaz, Brazil. Syn nov.

Rhynchospora rufa (Nees) Böckeler, Vidensk. Meddel. Nat. For. Kj0benhavn 1869: 149. 1869. Based on Psilocarya rufa Nees.

[Pachymitra rufa (Nees) Nees ex Böckeler, Linnaea 37: 616. 1873. Based on Psilocarya rufa Nees. Invalid name published as a synonym.]

Psilocarya mexicana Liebmann, Dansk. Vidensk. Selsk. Skr. Kjøbenhavn V, 2: 248. 1851. Type. Liebmann (C) from Dept. Vera-Cruz, between La Isleta and Malvapam, Mexico.

[Rhynchospora mexicana C. Wright ex Sauvelle, FI. Cubana 182. 1871. Type. C. Wright 2683 (K, NY) from Cuba. Later homonym of R. mexicana Steudel 1855.]

Rhynchospora velutina Böckeler var glabrescens Böckeler, Bot. Jahrb. 1: 364. 1881. A new name for Psilocarya mexicana Liebmann.

Psilocarya pauloensis Böckeler, Cyp. Nov. [ = Beitr, Kennt. Cyper.] Heft. 2: 24. 1890. Type. Loefgren 143 in part (S) from Itapetininga, São Paulo, Brazil.

Rhynchospora rufa Böckeler var liebmenniana C. B. Clarke in Urban, Symb. Antil. 2: 117. 1900. A new name for Rhynchospora mexicana C. Wright ex Sauvelle, 1871, non Steudel 1855.

[Rhynchospora aureaeformis C. B. Clarke, Illustr. Cyp. t. 71, f. 3. 1909. No type cited. Nomen nudum.]

Rhynchospora velutina Böckeler var divergens (Nees) Böckeler ex Kükenthal, Bot. Jahrb. 75: 173. 1950. Based on Psilocarya divergens Nees.

Rhynchospora velutina Böckeler var pohlii (Nees) Böckeler ex Kükenthal, Bot., Jahrb. 75: 173. 1950. Based on Psilocarya pohlii Nees.

Rhynchospora velutina Böckeler var sellowiana (Kunth) Böckeler ex Kükenthal, Bot. Jahrb. 75: 173. 1950. Based on Dichromena sellowiana Kunth.

Rhynchospora kükenthalii Herter, Rev. Sudamer. Bot. 9(5): 158. 1953. A new name for Dichromena sellowiana Kunth, not Rhynchospora sellowiana Steudel, 1840.

Type. Sellow (B) from “Brasilia meridionalis.”

Kükenthal (1950) made a segregation between R. velutina and R. rufa as follows:

Culmus foliaque plerumque molliter pilosa. Vaginae foliorum basilarium brunneae. Spiculae 4-5 mm longae. Basis styli 3/4 nucis aequans. R. velutina.

Culmus glaber. Folia glabra vel parce pilosa. Vaginae foliorum basilarium violaceo-brunneae. Spiculae 5-7 mm longae. Basis styli 1/2 nucis longa. R. rufa.

I failed to find that this distinction is valid. As can be seen in the scatter diagram of Fig 16, no correlation exists between the size of spikelets and the presence or absence of pubescence on leaves and culms. The color of radical leaf sheaths also shows no correlation with the occurrence of pubescence. For instance, the combination of purple-brown sheaths and densely pubescent leaves and culms, a feature that contradicts the Kükenthal’s key, has been observed in at least three specimens cited above, i e, Duarte 3547, Eiten & Eiten 1764, and Heringer 8546. Concerning the size of spikelets, the scatter diagram shows no evidence that the species complex involves two or more different populations. In his descriptions, Kükenthal mentioned that the achenes of R. velutina are 1 mm long while those of R. rufa are 1 3/4 mm long. As illustrated in Fig. A to E, the achenes of the R. velutina complex have a wide range of variation in both the size and the shape of the achene-body as well as the style-base, not showing any discontinuity in size and shape. Similarly, the relative length of the style-base to the achene-body makes no difference between the hairy R. velutina and the glabrous R. rufa. Furthermore, as to the degree of pubescence, the variation has been observed from dense pubescence on both leaves and culms to weak pubescence or only marginal ciliae on leaf-blades only, making no clear discontinuity between hairy and glabrous plants. Any of these characters in discussion shows no geographical significance. Thus demonstrated, I am quite convinced that R. velutina and R. rufa represent the same taxon, which may or may not be hairy on leaves and often also on culms. When the two plants are merged, the name R. velutina becomes a correct name for this species on account of its priority.

Distribution:Mexico North America| West Indies| Colombia South America| Venezuela South America| Guyana South America| French Guiana South America| Brazil South America| Argentina South America|