Monographs Details: Senna pendula var. indistincta 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 - Weakly frutescent, at anthesis 1.5-2.5 m, the membranous foliage either glabrous or the lfts thinly pilosulous dorsally with fine straight hairs up to 0.4-0.7 mm; petiolar glands between the proximal sometimes also the second pair of lfts; lfts (3-)4-6 pairs, the distal pair cuneate-oblanceolate or -obovate 2.5-3.5 x 1-1.5(-1.7) cm, the secondary camptodrome veins (5-)6-8 pairs, the tertiary venulation weak, irregular or fully immersed; longest sepal 9.5-14 mm; longest petal 18-24 mm; blade of staminodes trapeziform, broadest at the subun- dulately truncate apex, (2.7-)3-4 x 2-2.5 mm; long filaments 12-18 mm, their anther 5.5-8 x 1.3-1.8 mm; ovary glabrous or laterally strigulose; style 5-8 mm; ovules 52-107; pod of var. glabrata.—Collections: 9. [Key: "Lfts obovate or oblanceolate, rarely elliptic-oblanceolate, broadest above (exceptionally near) the middle; range of the whole sp. Style 5-10 mm and filaments of 2 long stamens (10-)11-20 mm. Plants of Brazil, Peru and s. through Bolivia to Paraguay and n. Argentina. Lfts not sharply reticulate on either face, the tertiary venulation faint or erratic or immersed. Anther of 2 long abaxial stamens 5.5-8 mm, obviously shorter than its filament; widespread. Distribution along rivers of n.-e. Brazil in Para, Maranhao and e.-ward; petiolar glands at proximal and rarely the second pair of lfts; blade of staminodes amply trapeziform 2.7-4 X 2-2.5 mm."]

Distribution and Ecology - Disturbed and cut-over forest, creek margins and riverbanks, both on varzea and terra firme, below 200 m, locally plentiful in the lower Tocantins basin and s. margins of the Amazon estuary in Para and adjacent Maranhao, lat. ±1°-7°S; one record from Pernambuco (Tapera), perhaps introduced from further w.—Fl. III-VIII.

Discussion:The var. indistincta is a somewhat nebulously defined entity in which the large longistylous flower of var. glabrata is combined with the membranous penninerved (non-reticulate) leaflets common to the brevistylous Amazonian varieties of the species. Dilated trapeziform staminodes are characteristic of var. indistincta, but these are known also from a few populations of var. glabrata in n.-e. Mato Grosso and the sources of the Tocantins in the Federal District, and are therefore not truly diagnostic. It is the coincidence with dispersal of a distinctive character-syndrome, but not with any one unique character, that enables us to recognize in var. indistincta another regional expression of the plastic S. pendula.
Distribution:Pará Brazil South America| Maranhão Brazil South America| Pernambuco Brazil South America|