Chamaecrista basifolia (Vogel) H.S.Irwin & Barneby
-
Authors
Howard S. Irwin, Rupert C. Barneby
-
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.
-
Family
Caesalpiniaceae
-
Scientific Name
-
Type
Holotypus, †B; no isotypus known to survive, but the protologue decisive.
-
Synonyms
Cassia basifolia Vogel, Cassia basifolia var. aristulata Hassl.
-
Description
Species Description - Erect, when young simple virgate, later awkwardly few-branched, in age basally suffrutescent herbs of 1-2 seasons’ duration, at anthesis (1.5-)2.5-10(-15) dm, except at the lowest nodes leafless, the stems clothed in loosely imbricated or shortly discrete pairs of appressed, amply cordate-amplexicaul venulose stipules, the few early developed lvs 2-foliolate, the rest reduced to a seta concealed between pairs of stipules, the stems and olivaceous concolorous foliage varying from pilose nearly throughout with fine spreading septate hairs to 0.8-2(-2.7) mm to glabrous except for a few short incurved hairs on stems or minutely ciliolate stipules, the sepals, ovary and pod consistently pilosulous. Stipules subsymmetrically ovate- or deltate-acuminate from deeply cordate base, (6-)9-21 x (3.5-)4-12(-14) mm, the basal angles rounded, the apex sharply mucronate or spinulose, the plane blades stiffly chartaceous, palmately many- nerved from base, the lowest of the primary stem and of some branchlets narrower and few-veined. Lvs developed at ±8-12 nodes following the cotyledons, early shed, 11-28 mm, shortly petioled; petiole openly shallow-sulcate ventrally, 2.5-5.5 mm, at middle 0.3-0.5 mm diam; petiolar gland 0; lfts 1 pair, ascending from tip of petiole turned half face to face, in outline dimidiately obovate (8-) 10-21 (-24) x (4—)6—12(—14) mm, at apex obtuse to truncate and commonly also acuminulate or mucronulate, at base semi-cordate, the submembranous blades ±4-6- nerved from pulvinule by the strongly displaced, closely penni-nerved midrib with 3-5 major veins on its proximal side, the venation equally prominulous on both faces. Peduncles exactly axillary, to 1 mm, 1-fld but often several-bracteate; pedicels widely ascending, at anthesis subfihform thickened in fruit, (7—)9—21 mm, bracteolate near or above middle; bracteoles lanceolate or narrowly ovate, several nerved, 2-3.5 mm; buds slenderly ovoid-acuminate, loosely pilosulous at base or throughout; sepals dull red or reddish-brown, lance-acuminate to narrowly ovate- acute, 6—9.5 mm; petals yellow fading pinkish-brown, at anthesis campanulately ascending, not or shortly exserted beyond the longest sepal, obovate-cuneate to oblong-obovate, 7.5-10 mm, the abaxial pair sometimes a trifle larger than the 3 adaxial but neither oblique nor differentiated in texture; stamens 5, oppositisep- alous, the often reddish anthers narrowly lance-acuminate, 4.5-6.6 mm, their sutures mealy-puberulent; style cylindroid, glabrous, 2.5-3 mm, at early anthesis about as long as the longest anther; ovary densely pilosulous; ovules (7—)8—11(— 12). Pod ascending, (2.5—)3—4.5 x 0.6-0.7 cm, the castaneous nigrescent valves transversely venulose, pilosulous; seeds obliquely oblong, 4.1-4.7 mm, the testa pale brown, dull, microscopically papillate, mucilaginous when wetted, the lines of pits visible externally as faintly paler dots, not excavated.—Collections: 79.
Distribution and Ecology - Virgin campo and cerrado, persisting and often flourishing in disturbed or burnt campo and along highways, occurring both in abundant colonies and as scattered individuals, 850-1400 m, widespread over the Planalto from the upper R. São Francisco valley in Minas Gerais (Montes Claros s. to Lagôa Santa), w. in scattered stations over the highlands of s. Goiás to the Araguaia-Xingú divide in e. Mato Grosso; apparently isolated on the upper Rios Pardo and Tieté in s.-e. São Paulo (Mogi-Mirim; Itú).—Flowering primarily IX-III, but occasional through the year.
-
Discussion
A species instantly recognized by the dorsiventrally flattened, ribbonlike files of cordate stipules loosely imbricated along the stems and interrupted here and there by a few small axillary flowers. In the adult plant stipules assume the photosynthetic function of the foliage but normal foliaceous leaf-blades are regularly produced from about ten nodes of the primary stems and sometimes again at a few nodes low on the lateral branchlets. Upward all leaves are reduced to the terminal seta of the suppressed petiole, each concealed by a pair of appressed stipules. In the form of the bifoliolate perfect leaves and of the pentamerous almost regular corolla, Ch. basifolia greatly resembles the more erect forms of Ch. rotundifolia, and is presumably derived from it or an immediate common precursor. There is some small variation in flower-size, perhaps partly seasonal and in any case without geographical correlation. Vesture of the plant varies below the always pilosulous flower-buds and ovary from relatively long and copious, composed of slender, widely spreading, multiseptate hairs scattered along the stems and over faces and margins of the stipule-blades, to almost none, when reduced to a few short cilia on the stipule margins and a line of short incurved hairs along one face of the stem-internodes. The range of the most hairy form extends from central Minas Gerais into east-central and southeastern Goiás; that of the most glabrous from east-central Mato Grosso south through southwestern Goiás and the Minas Triângulo to São Paulo. However a broad band of intermediate forms and of occasional heterogeneous populations has been traced from Chapada dos Veadeiros south into the Federal District, where glabrous and pubescent phases are found close together. While none of the glabrous form is yet known from the São Francisco basin and none of the hairy one from Mato Grosso the intergradation between the extremes is so gradual and so frequent that their taxonomic recognition should be avoided.
-
Distribution
Minas Gerais Brazil South America| Goiás Brazil South America| Mato Grosso Brazil South America| São Paulo Brazil South America|