Monographs Details: Senna pendula var. praeandina 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 - Diffuse or scandent, at anthesis 1-5.5 m, usually densely gray- or yellow-pilosulous, the lfts dorsally over the whole face, rarely glabrate except for patch in anterior basal angle of midrib; petiolar glands between all pairs of lfts except the distal one; lfts 4-6 pairs, the distal pair (2.2-)2.5-4.7 x (0.8-)0.9-2.1 cm, the secondary venation fully immersed or faintly delicately raised on one or both faces; longest sepal 8-11(-13.5) mm; longest petal 14-18(-20) mm; blade of staminodes oblong, 3-4.5 x 0.8-1.5(-l.9) mm; long filaments 12-17(-18) mm, their anther 6-7.5(-8) x 1.3-1.9(-2) mm, its beak 0.5-0.8 x 1 mm; ovules 88-108; body of pod 7-11 x 0.9-1.2 cm, subcylindric, the seeds 2-seriate.—Collections: 24. [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 in the e. foothills and interior valleys of the Andes from centr. Peru to n.-w. Argentina; petiolar glands between all but the distal pair of lfts; blade of staminodes either shorter than 2 mm or narrower than 1.6 mm (or both). Longest sepal 8-11 mm and longest petal 14-18(-20) mm; filament of 2 long abaxial stamens 12-18 mm; blade of staminodes oblong 3-4.5 mm; Peru, Bolivia."]

Distribution and Ecology - Openings in dense wet forest, riverbanks and clearings, mostly 150-500, in centr. Peru (on Rio Chanchamayo in Junin) to 1800 and in Bolivia rarely (Coripata) up to 1600 m, scattered along the e. foot and lower intermontane valleys of the Andes between 8° and 19°S, from the upper Huallaga and middle Ucuyali rivers in San Martin and s. Loreto in Peru s.-e. to the headwaters of Rio Mamore in Bolivia, e. feebly across Sa. de Divisor to the head of Rio Jurua in Acre and the Guapore valley in Rondonia, Brazil.—Fl. IV-VIII.

Discussion:With var. praeandina we embark on the description of the more numerous varieties of S. pendula in which the leaflets are obviously pinnately veined but only weakly, sinuously or indefinitely reticulate. In this context the syndrome of relatively large, longistylous flowers, glands between all but the distal pair of leaflets and the elongately oblong staminodes is distinctive. The flask-shaped short anthers, which are abruptly strangulated below the dilated, broad-headed beak, are visually distinctive also, but difficult to describe in differential terms. In the known populations of var. praeandina in Peru and adjoining Brazil the plants are for the most part densely pilosulous, often with yellowish hairs, but the Bolivian ones are more glabrous, in this respect resembling the southwardly vicariant Argentine var. eriocarpa, which see next below.
Distribution:Junín Peru South America| La Paz Bolivia South America| San Martín Peru South America| Loreto Peru South America| Acre Brazil South America| Rondônia Brazil South America| Bolivia South America|

Common Names:Retama-huasca