Senna racemosa var. moctezumae

  • Title

    Senna racemosa var. moctezumae

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Senna racemosa var. moctezumae H.S.Irwin & Barneby

  • Description

    196b. Senna racemosa (P. Miller) var. moctezumae Irwin & Barneby, var. nov., pistillo glaberrimo brachystylo cum var. racemosa congruens sed ab ea pube omnium partium densa pilosula aureola, foliorum majorum foliolis 8-10 (nec 4-8)-jugis, legumine longiore 10-19.5 (nec 8-12) cm longo patriaque remota submontana abstans.-MEXICO. Hidalgo: mountains along Rte. 85 ± 1 mile n.-e. of Jacala, 23.III. 1961 (fl), Robert Merrill King 4212.-Holotpyus, NY; isotypi, MICH, US.-Ibid., 1.VII. 1948 (fr), H. E. Moore & C. E. Wood 3673.-Paratypi, NY, MICH = U.S.D.A. Plant Introduction 260707, cult, at LASCA (A. Griffiths 4990, NY).

    Cassia ekmaniana sensu Isely, 1975, p. 82, quoad descr., basionym. exclus.

    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.

    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.

    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.