Chamaecrista desvauxii var. brevipes

  • Title

    Chamaecrista desvauxii var. brevipes

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Chamaecrista desvauxii var. brevipes (Benth.) H.S.Irwin & Barneby

  • Description

    1k. Chamaecrista desvauxii (Colladon) Killip var. brevipes (Bentham) Irwin & Barneby, comb. nov. Cassia desvauxii var. (ß) brevipes Bentham in Martius, Fl. Bras. 15(2): 157. 1870.—". . . in provincia Goyaz e. gr. prope Curralinho et in Serra dos Christaës: Pohl; ad Natividade: Gardner n. 2125., inter Funil et S. João: Burchell. In Guiana quoque plantain legit Schomburgk."—Lectotypus (Irwin, 1964, p 99)- Pohl 843 e "Rio Lage in Serra dos Chrystaës"; isotypus, K! paratypi, Gardner 2125, BM! Burchell 8943, 9038, K! Robt. Schomburgk 190, K!—Cassia tetraphylla var. brevipes (Bentham) Irwin, Mem. N.Y. Bot. Gard. 12(1): 99 (exclus. syn. Chamaecrista lehmannii), fig. 350 (map). 1964.

    Cassia brevipes DeCandolle ex Colladon, Hist. Casses 119, t. 9, fig. A. 1816.—"Hab. in Panamaide(Lagasca)."-Holotypus, ticketed "no. 65, Lagasca, 1807," G-DC! = F Neg.33458.-Chamaecrista brevipes (DeCandolle ex Colladon) Greene, Pittonia4: 31. 1899. Cassia tetraphylla var. aurivilla Irwin, Mem. N.Y. Bot. Gard. 12(1): 96, fig. 350 (map). 1964 (non C. tetraphylla var. brevipes (Bentham) Irwin, 1964).

    Cassia desvauxii var. stipulacea Pilger, Engler, Bot. Jahrb. 30: 158. 1901.—"Mattogrosso: zer- streut am Rande des Uferwaldes am oberen Ronuro ([Hermann Meyer] n. 621.—Fruchtend im Mai 1899)."—Holotypus, †B; isotypus, US!

    Cassia brevipes sensu Bentham, 1871, p. 568; Schery, 1951, p. 58.

    Habit, foliage, vesture and fl of var. mollissima; stipules shorter than internodes; petiolar gland always sessile, 0.6-2 mm diam; pedicels (1—)2—8(— 12) mm, at once shorter than subtending lf and the longer sepals; pod (17-)20-35 (—40) x (5—)6— 12.5(—14) mm, the valves strigose or pilosulous, the vesture gray, sordid, or yellow; ovules (8—)9—15.

    Savanna habitats of var. mollissima, scattered within the latter’s range but less widespread and vicariantly alio- or locally sympatric: Gulf coastal plain of Honduras (Cortes); Mosquito Coast of Nicaragua (Zalaya); upland w. and Pacific Costa Rica (San José and Puntarenas); Panama (Chiriquí, up to 1550 m, Code and Panamá); n.-w. Venezuela (Zulia, Lara); llanos of e. Colombia s. to Cordillera de Macarena; n.-e. Peru (Loreto); Guayana Highland in Venezuela (Amazonas, Bolívar) and adjoining Rupununi District of Guyana and Terr. do Roraima in Brazil; coastal plain of Surinam and Amapá, Brazil; and reappearing s. of the Amazonian Hylaea from s. Ceará, n. Goiás, n.-e. Mato Grosso and the upper forks of ríos Beni and Mamoré in Bolivia s. to s.-w. Goiás, s. Mato Grosso and immediately adjacent Paraguay (Sa. de Amambay).—Fl. in Central America X-III, in equatorial latitudes irregularly through the year, on the Brazilian Planalto mostly (X-)I-VI.

    The implausibly interrupted dispersal of var. brevipes coincident with an internal range of variability that often, but not always, runs parallel to that of immediately vicariant or even sympatric var. mollissima suggests that the entity as defined herein is not phyletically natural but rather an assembly of minor variants that independently have acquired abbreviated pedicels. This however is a striking feature and maintenance of a traditional var. brevipes, if modified to admit a pod so variable in length, outline and vesture as to include var. aurivilla of the last revision (=C. brevipes Bentham), serves a useful taxonomic purpose. Correlation between a short, proportionately broad pod and yellow pilose vesture of the valves, well sustained in Costa Rica and Panama, fails to define two short- pedicelled forms in South America. Yellow pilose vesture occurs on short and narrow, long and narrow, and broad short pods, and these cannot be sorted in meaningful geographic patterns. In fact most of the South American material that has been referred to var. aurivilla because of the loose lutescent vesture of the pod or ovary has mature pods 3-4 times longer than wide, except for vesture exactly as in var. mollissima. The wide-valved pod, whether long or short, that could accommodate relatively long seeds does not in fact do so, and length of pod is only weakly correlated with ovule-number.

    Over most of its range var. brevipes has the adult fruticose or suffruticose habit of var. mollissima. On the Orinoco-Amazon divide in Venezuela and Colombia and again in northern Goiás a possibly distinct entity may be characterized by a simple or distally few-branched wandlike habit that coincides with relatively narrow leaflets suggestive of var. langsdorfii. On the Esmeralda savannas in Amazonas this is sympatric with frutescent var. ventuarensis, and in Vaupés with var. piptostegia.

    A Peruvian locality for var. brevipes mapped by Irwin (1964, l.c.), based on a Pearce collection from Pata, needs confirmation; the plant may have originated at Pata in Bolivia. The variety is known in Peru definitely only from Loreto (W. Fox 54, K).