Chamaecrista roraimae (Benth.) Gleason
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Authors
Howard S. Irwin, Rupert C. Barneby
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Authority
Irwin, Howard S. & Barneby, Rupert C. 1982. The American Cassiinae. A synoptical revision of Leguminosae tribe Cassieae subtrib Cassiinae in the New World. Mem. New York Bot. Gard. 35, part 2: 455-918.
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Family
Caesalpiniaceae
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Scientific Name
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Type
Lectoholotypus (Pittier, Cat. Fl. Venezol. 374. 1945), Appun 1231, K (hb. Hook.)! = NY Neg. 1533; paratypi, Rob. Schomburgk 582, FI, G = F Neg. 28013, K, & Rich. Schomburgk 840, K, LE!
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Synonyms
Cassia roraimae Benth.
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Description
Species Description - Shrubs up to 3.5 m (sometimes flowering precociously as herbs only 1.5-2 dm), with knotty trunks to 2 cm diam, slender, soon leafless branches, and densely leafy annotinous branchlets, the stems, lf-stalks and inflorescence villosulous and setulose with short incurved and (especially the lf-stalks) longer straight ascending often yellowish setules up to 0.4—1(—1.3) mm, the foliage ± bicolored, the stiffly chartaceous lfts drying brown, darker above, ciliolate, but the faces varying from glabrous to finely villosulous. Stipules erect, broadly lance-acuminate, shortly above the subsymmetrically rounded base 2-3.5 mm wide, the blades either glabrous except ciliolate margins or densely pubescent dorsally, all deciduous before the lf. Lvs spreading-ascending, 3-10.5 cm, short-petiolate, the expanded blade lance- or oblong-elliptic in outline; lf-stalk 2.5-9.5 cm, narrowly margined ventrally, the sulcus almost or quite closed; petiole including wrinkled pulvinule 3-5 mm; petiolar gland immediately below first pair of lfts, bucket- or squatly peg-shaped, (0.5-)0.6-l mm diam, not or little wider than the head of the thick short stalk, 0.5-1.1 mm tall; 1-several smaller stalked glands between some distal pairs of lfts; lfts of major cauline lvs 14-27 (on occasional lvs of axillary branchlets fewer) pairs, diminished at base and toward apex of lf-stalk, separated by segments of lf-stalk slightly > or < than their greatest width, in outline narrowly lance- or linear-oblong, 3.5-17 x 1.2-3.6 mm, distally subfalcate and abruptly contracted into a cusp 0.3-1.2 mm, at base deeply angulate-cordate on the narrow adaxial side, more shallowly cordate on the other, from base 3-5-nerved, the midrib strongly displaced but intramarginal, the venation prominulous both sides or commonly immersed above. Peduncles axillary solitary 2-5 mm, or sometimes serially geminate, the distal one then briefly adnate to stem, one or both 1-2-fld; bracts and bracteoles resembling stipules but only 3.5-7.5 mm; pedicels ascending, 10-25 mm; buds ovoid-acuminate, minutely pilosulous and often also ± yellow-setulose; sepals greenish or brownish where exposed in bud, with broad petaloid margins, lance- or ovate- acuminate, 12—16(—17) mm; petals yellow, 4 broadly oblanceolate to obovate- cuneate, 20-28 mm, the fifth falcately dimidiate, slightly longer or shorter than the rest; stamens 10, the anthers 5.5-9.5 mm; gynoecium divaricate; ovary densely strigulose or villosulous; style linear-cylindric, puberulent to middle or glabrous, 10-14 mm; ovules 12-15. Pod spreading-ascending, 5-6.5 x 0.8-0.9 cm, the valves reddish-brown, minutely pilosulous or yellow-villosulous; seeds unknown.—Collections: 25.—Fig. 37 (androecium).
Distribution and Ecology - Savanna-margins and rock-outcrops (n.-ward) or cerrado and margin of gallery-forest (s.-ward), local in two widely disjunct areas: plateaux at 1000-1200 m about the s.-e. margins of the Guayana Highland in s.-w. Guyana and adjoining Venezuela (Kamarang trail; río Cuquenan) and Brazil (Mt. Roraima; Sa. Tepequem); and near 1000 cm on Chapada Diamantina and n. Serra do Espinhaço from centr. Bahia (Sa. Agua de Rega) s. to the headwaters of Rio Pardo in extreme n. Minas Gerais.—Fl. VIII-II (n.-ward), XII-II (s.-ward).
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Discussion
An exceptionally handsome chamaecrista, resembling Ch. olesiphylla in the large flower but differing in the more erect stature, deciduous stipules, and longer leaves with pliant footstalks and less crowded leaflets. The populations in southeastern Brazil have dorsally pubescent stipules, leaflets at least puberulent dorsally and often on both faces, and densely strigulose ovary, whereas those of the Guayana Highland, separated by a distance of 2900 km, have dorsally glabrate stipules, mostly glabrous (rarely puberulent) leaflets, and yellow-villosulous ovary. In other respects they are closely similar. Bentham described the petiolar gland of the northern population as sessile, urceolate or scutellate; and we can find no discontinuity in this respect between the northern and southern lobes of the species range.
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Objects
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Distribution
Bahia Brazil South America| Minas Gerais Brazil South America| Guyana South America| Venezuela South America|