Monographs Details: Senna cana var. pilosula 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 1: 1-454.
Description:Variety Description - At anthesis 1-3 m; vesture of loose rusty sinuous hairs up to ±0.3-0.6 mm, the hornotinous branchlets, lf-stalks and lower face of lfts all densely pilosulous; stipules essentially of var. cana, (4-)6-10 x (l-)2-4 mm, at base auriculate-amplexicaul; glands usually 0 at proximal and distal pairs, elsewhere stipitate; lfts 4-6 pairs, varying from elliptic-oblanceolate to narrowly obovate, either obtuse- mucronulate or deltately acute, 3-6.5 x 1.1-2.6 cm, 2.1-3 times as long as wide; floral bracts 4-8 x 1.4-2.8 mm; fls relatively small, the long petal 16-20 mm; pod unknown.—Collections: 4. [Key: "Vesture of lower face of lfts pilosulous with loosely incumbent, weakly sinuous hairs up to 0.3-0.6 mm, or minutely sparsely strigulose, or quite glabrous; Atlantic slope of Chapada Diamantina s. through e. Minas Gerais to Rio Doce in Espirito Santo. Stipules linear-setiform erect, at base less than 1 mm wide, early caducous; valves of pod narrowly winged along each side of both sutures, the seed-locules consequently extending to neither margin of the fruit; local on upper Rio Contas in Bahia. Lower face of leaflets incumbently pilosulous. Bracts narrowly lance-acuminate or-caudate 4-8 x 1.4-2.8 mm, deciduous; relatively southern from Rio Pardo s.-ward."]

Distribution and Ecology - Habitat scarcely known, sometimes in caatinga thickets or about rock outcrops, ±300-700 (?) m, local in the valleys of Rios Pardo and Jequetinonha in s.-e. Bahia and adjoining Minas Gerais, and in aberrant (possibly distinct) form in the valley of Rio Doce in centr. Espirito Santo (Colatina); cultivated in Rio de Janeiro (RB).—Fl. II-III.

Discussion:This and the variety next following seem clearly distinct from var. cana in their looser and longer pubescence of incumbent or sinuously ascending, not crisped and matted hairs, but resemble it in all other respects. Their status is, however, provisional, pending discovery of the pod. Our one collection from Espirito Santo (Duarte 9010, M, NY) is notable for the presence of a gland between the proximal pair of leaflets and for leaflets themselves rather broader and more nearly obovate than usual in S. cana sens. lat. Its general habit somewhat suggests the coastal S. australis, but the flower is much smaller and the foliage of thinner texture and less prominently reticulate. Here again the pod may provide crucial evidence.
Distribution:Bahia Brazil South America| Minas Gerais Brazil South America| Espirito Santo Brazil South America| Rio de Janeiro Brazil South America|