Chamaecrista desvauxii var. saxatilis (Amshoff) 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

Chamaecrista desvauxii var. saxatilis (Amshoff) H.S.Irwin & Barneby

Type

Cassia tetraphylla Desvaux var. saxatilis Amshoff, On S. Amer. Papilionaceae 27. 1939.—"Suriname, Upper Litanie Riv. (mount Knopaiamoi, Rombouts 809 . . .)."—Holotypus, U!—C. saxatilis (Amshoff) Irwin, Mem. N.Y. Bot. Gard. 12:(1): 86, fig. 348 (map). 1964

Synonyms

Cassia tetraphylla var. saxatilis Amshoff, Cassia saxatilis (Amshoff) H.S.Irwin

Description

Species Description - Slender erect, usually single-stemmed from shallow roots, paniculately branched distally 3-10 dm, the branches either strictly ascending or plagiotropic, the foliage olivaceous glabrous or glabrous ciliolate; stipules submembranous broadly lance-ovate acute or acuminate, persistent, the larger ones 6-14 x 2-4 mm, as long or only 1/3 as long as internodes; longer lf-stalks 4-8 mm, the petiole (3-)3.5-6 mm, the rachis 1-2.5; petiolar gland scutellate or shallowly concave 0.5-1.4 mm diam subsessile or shortly stipitate, in profile obconic or squatly studshaped, 0.2-0.8 mm tall; lfts subdimidiately obovate or obliquely broadly oblanceolate, the proximal pair usually slightly larger (in sleep covering the distal pair), the larger ones 10—19(—23) x 4-8(-9) mm; pedicels very slender wiry 2-3.3(-4) cm, surpassing If; longer sepals (7—)9—11 mm; long petal (5—)7—11(—14) mm; pod 17—27(—38) x 4.5-5.5(-7) mm; ovules (6—)7—9(—11).

Distribution and Ecology - Sand savanna and outcrops in forest or along rivers, a pioneer colonist of temporary river islands, soil-filled crevices and depressions in granite rock faces, 10-550 m, interior Surinam, French Guiana, and Amapá, Brazil, from the middle Coppename River (Voltz Berg) e. to Rio Araguarí, s. to s. slope of Sa. Tumucumaque on the headwaters of Rio Jarí, in French Guiana and Amapá coming out to the coast (at Cayenne) or the coastal plain (downstream from Porto Platon).—Fl. year around.

Discussion

Readily distinguished from sympatric var. mollissima by the slender habit, small flower, and short few-ovulate pod. The variety is more closely related to the distantly allopatric var. triumviralis which occupies similar microhabitats on granitic knobs and associated savannas of the middle Orinoco valley, but differs in diminished leaf- and stipule-blades, smaller sessile glands, and shorter pedicels.

Distribution

French Guiana South America| Amapá Brazil South America| Cayenne French Guiana South America| Brazil South America|