Monographs Details: Senna multifoliolata var. eurystegia 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 - Treelets 6-8 m; stipules and pod as described in key to varieties; long abaxial petals 16-17 mm; stamens relatively short, the anthers of 3 abaxial ones ±6 mm, scarcely shorter than their filament.—Collections: 2. [Key: "Stipules long or permanently herbaceous, asymmetrically rhombic-ovate from semicordate base, mostly 8-12 x 6-8 mm, the blade extrorsely complicate; bracts similar in texture and outline, (3-)4-10.5 mm; ovules 14-26; Sa. Madre del Sur in centr. Guerrero and s. Oaxaca.3. Fls dolichostylous, the style 6.5-10 mm and the filaments of 3 long abaxial stamens 10.5-12.5 mm, their anther ±8 mm; ovules 20-26; s. Oaxaca (mun. Miahuatlan and Pochutla). Fls of moderate size, the long sepal ±11 mm, the longest petal ±24 mm, the 3 long abaxial filaments 12-13 mm, their anther ±7 mm; style 6-6.5 mm; body of pod 10-12 x 1.1-1.3 cm; high Sa. Madre del Sur in w. Guerrero. Fls brachystylous, the style 2-2.5 mm, the filaments of 3 long abaxial stamens (5.5-)6-6.5 mm, their anther ±6 mm; ovules 14-18; centr. Guerrero (Cerro Teotepec)."]
Distribution and Ecology - Dense mixed mesophytic forest, sometimes along streams, 2600-2700 m, known only from the slopes of Cerro Teotepec near 100° 10'W in Sa. Madre del Sur, s.-centr. Guerrero.
Discussion:This variety was collected first by George Hinton in 1939 but was left unnamed when his Mexican collections were under study at Kew. It is the most sharply marked form of S. multifoliolata, the broad folded stipules and the unexpectedly abbreviated androecium and style with proportionately diminished perianth being unmistakable.
Guerrero Mexico North America