Monographs Details: Senna spinescens var. schultesiana 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 - Characters as given in key and diagnosis.Key: "Lfts pilosulous on both faces; sepals subequal, 6-8.5 x 2.5-3 mm, except toward margin densely golden-strigulose dorsally; longest anther (excluding beak) 14-20 mm; style 1-2 x 0.6-0.7 mm; said to be trees 4-7 m; local on Vaupes and Apoporis rivers in s.-e. Colombia and adjacent Amazonas, Brazil.']—Collections: 7.

Distribution and Ecology - Riparian forest, at least sometimes inundated at flood seasons, 170-270 m, along rios Apoporis and Vaupes (Caiari) in Comisaria de Vaupes, Colombia and on upper rios Negro and Vaupes in n.-w. Amazonas, Brazil.—Fl. I-IV.

Discussion:Flowering specimens of var. schultesiana are sharply distinguished from var. spinescens by the pubescent foliage, diminished calyx and very large anthers, but the pods are identical. While all collectors agree that var. spinescens is a woody climber, sometimes working its way high into the canopy, Schultes and Zarucchi saw var. schultesiana in three stations as a tree 4-7 m, Steward as a treelet 3 m tall. If the difference in habit can be confirmed, the status of var. schultesiana may require reevaluation. The presence of recurving spines suggests, however, that a potentially lianalike or at least sarmentose habit of growth is a basic attribute of the species.
Distribution:Amazonas Brazil South America| Vaup├ęs Colombia South America|