Monographs Details: Senna pendula var. ambigua 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 - Like relatively small-fld var. glabrata, the stems and lf-stalks incurved-puberulent, the lfts pilosulous dorsally in anterior basal angle of midrib but otherwise glabrous, at least beneath intricately reticulate-venulose; petiolar glands 1-3; lfts 3-5 pairs, the distal pair 1.8-3.3 x 0.9-1.8 cm; longest sepal 8-13 mm; longest petal (13-)14-17 mm; blade of staminodes 1.6-2.3 x 1.7-2.1 mm; 2 long filaments 6.5-10 mm, their anther 6-7.7 mm, its beak 0.5-0.7 mm; style 3-4 mm; ovules 50-64; pod (little known) apparently like that of var. recondita, perhaps slightly narrower, the seeds 1-seriate.—Collections: 15. [Key: "Lfts obovate or oblanceolate, rarely elliptic-oblanceolate, broadest above (exceptionally near) the middle; range of the whole sp. Style at and after anthesis 1.5-5 mm and the 2 long abaxial filaments 6-11 mm. Plants of the Orinoco valley in Venezuela, of the Amazonia Hylaea, of the Paraguai basin, and of coastal s.-e. Brazil. Lfts intricately and finely reticulate on lower face; restinga of coastal Rio de Janeiro and Soa Paulo, Brazil (if brought hither by plants of Paraguai valley s.-ward from Mato Grosso cf. 126o. var. paludicola); seeds 1-seriate."]

Distribution and Ecology - Restinga thickets along the coast of eastern Brazil between Cabo Frio, Rio de Janeiro, and Ubatuba in extreme n.-e. Sao Paulo; cultivated in subtropical United States and elsewhere.—Fl. IX-X, III-IV, perhaps nearly throughout the year.

Discussion:The var. ambigua stands intermediate both morphologically and geographically between var. glabrata and var. recondita, although different from both in the brachystylous flower and correspondingly short filaments. The short broad staminodes agree with var. glabrata, while the compressed pod, relatively few uniseriate seeds and coastal habitat agree with var. recondita.
Distribution:Rio de Janeiro Brazil South America| São Paulo Brazil South America|