Monographs Details: Chamaecrista desvauxii var. graminea 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
Description:Latin Diagnosis - Chamaecrista desvauxii (Colladon) Killip var. graminea Irwin & Barneby, var. nov., a var. lineari (Irwin) Irwin & Barneby imprimis pedicellis elongatis 14-17 (nec 2-5) mm longis abstans.

Species Description - Very slender, flexuously procumbent herbs 1—4 dm, appearing glabrous below the strigulose ovary but the stems and lf-stalks sometimes puberulent or pilosulous, the very narrow grasslike lfts glabrous or ciliolate; stipules narrowly lance-attenuate 6-11 x 1.5-2.5 mm, persistent; lf-stalks 3-4.5 mm, the petiole 1.5-3.5 mm, the rachis 1-1.4 mm; gland sessile or shortly stipitate, 0.25-0.9 mm diam, in profile (0.1 mm longer) 0-0.4 mm shorter than diam of head; lfts linear-lanceolate acute or acuminate, the proximal pair only a trifle shorter than the distal, these up to 15-25 x 1-1.7 mm, 8-16 times longer than wide; pedicels subfiliform 14—27 mm; long sepal 12-17 mm; longer petals 13-16 mm; ripe pod unknown; ovules 8-10.—Collections: 3.

Distribution and Ecology - Sandy campo near 1000-1200 m, apparently rare and local, known from only three stations, one in centr. Sa. do Espinhaço near 18°40'S in centr. Minas Gerais and two in Chapada Diamantina near 11°20'-13°S (Jacobina; Mucujé) in centr. Bahia. Fl. in Minas Gerais IV-V, in Bahia VI-VIII, the full range unknown.

Discussion:

The foregoing description is based primarily on the ample type-series which, while resembling var. linearis in the extremely narrow grasslike leaflets, differs in the elongate pedicels which elevate the proportionately large fls to or beyond the level of the fulcrant leaf. With this we associate Blanchet 2536 from Jacobina, mentioned by Bentham (1870, p. 158) as one of the ambiguous forms connecting Cassia langsdorfii with C. gracilis and referred by Irwin (1964) to var. linearis, from which it differs in the developed pedicels. While it might appear a priori preferable to stretch definition of var. linearis to encompass both long- and short- pedicelled flowers, this will remain logically indefensible unless we abandon the same distinction between the otherwise inseparable vars. mollissima and brevipes.

A unicate specimen (Irwin et al. 32602a, NY) from Sa. do Tombador, in Chapada Diamantina about 100 km southwest of Jacobina, is perhaps referable to var. graminea but differs from the collections cited above in the rather stiffer (but still procumbent, sometimes adventitiously rooting) stems and slightly wider (to 2.5 mm), oblanceolate subobtuse rather than lance-attenuate leaflets. More ample collections from the highlands of Bahia are needed before the full range of variation in var. graminea can be known.

Distribution:Minas Gerais Brazil South America| Bahia Brazil South America| Brazil South America|