Monographs Details: Senna racemosa var. moctezumae 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 2: 455-918.
Description:Variety Description - Foliage densely loosely pilosulous with hairs up to 0.3-0.5 mm, the vesture of young lvs and inflorescence golden; lvs 11-25 cm; lfts (6-)8-10 pairs, the largest 2.5-5.3 x 0.9-2.1 cm, in outline elliptic, either acute or obtuse mucronulate, the secondary veins 6-8 pairs, the mature blades reticulate on both faces; calyx a trifle larger than that of var. racemosa, the outer sepals 3-4.5 mm, the inner 4.5-6 mm; 4 petals 12-16 mm, the odd petal 14-16 mm; anthers glabrous or minutely puberulent with a few incurved hairs up to 0.2 mm; ovary glabrous; style 1.5-2 mm; body of pod (10-) 11-19.5 x 1.2-1.6 cm.-Collections: 15. [Key: "Ovary and pod glabrous; mature lfts reticulately venulose on upper face; e. Mexico (s.-e. San Luis Potosi to Yucatan Peninsula), n.-e. Guatemala (Peten) and far w. Cuba; local in s.-w. Mexico (w. Michoacan and adjoining Colima). Lfts of larger lvs 8-10 pairs; pod (unknown in s.-w. Mexican var. coalcomanica) 11-19.5 cm, the seed-locules 6-10 mm long; distantly allopatric. Lfts densely softly pilosulous on both faces; local at ±1000-1400 m in valley of rio Moctezuma in s.-e. San Luis Potosi and closely adjoining Queretaro and Hidalgo."]

Distribution and Ecology - Rocky hillsides, cliff ledges and road-cuts, on limestone bedrock, 1000-1400 m, local on the Gulf slope of Sa. Madre Oriental drained by rio Moctezuma, lat. 20°45'-21°25'N in extreme s.-e. San Luis Potosi and closely adjacent Queretaro and Hidalgo.-Fl. III-V, occasionally later. Cultivated (as Cassia ekmaniana) in s. California and s. peninsular Florida, fl. in summer.

Discussion:The handsomely floriferous var. moctezumae, strongly isolated from the rest of its species on the Gulf slope of Sierra Madre Oriental, is morphologically intermediate between var. racemosa, of which it has the reticulate mature leaflets and glabrous brachystylous pistil, and var. sororia, like it in the relatively numerous pairs of leaflets and the copious loose vesture but unlike in the immersed tertiary venulation of the leaflets and in the rusty-pilosulous ovary. The remotely allopatric var. coalcomanica is closely similar in facies, but has finely strigulose leaflets and a style about 3 mm long.
Distribution:San Luis Potosí Mexico North America| Querétaro Mexico North America| Hidalgo Mexico North America| California United States of America North America| Florida United States of America North America|