Senna birostris var. hookeriana (Gillies ex Hook. & Arn.) 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.

  • Family

    Caesalpiniaceae

  • Scientific Name

    Senna birostris var. hookeriana (Gillies ex Hook. & Arn.) H.S.Irwin & Barneby

  • Type

    Holotypus, K (hb. Hook.)! = NY Neg. 1566; isotypus, FI (hb. Webb.)!—Non Senna hookeriana Batka, Bot. Zeit. 21: 264. 1863.

  • Synonyms

    Cassia hookeriana Gillies ex Hook. & Arn.

  • Description

    Variety Description - Low bushy shrubs 0.5-2 m, with atropurpureous older branchlets, appearing glabrous but the very young stems, lf-stalks and margin of lfts thinly strigulose- pilosulous with straight subappressed or incurved hairs up to 0.2-0.45 mm, the lfts glabrous on both faces, dull olivaceous but paler beneath, the racemes either lateral or crowded into a corymbiform panicle; stipules linear-lanceolate or lance- attenuate 3.5-6.5 x 0.2-0.7, early caducous; lvs (4-)5-12 cm; lfts (5-)6-11 pairs, narrowly lanceolate, lance-oblong or -elliptic, acute mucronulate or obtuse acu- minulate, less often ovate acute, up to l-2.7(-3) x (0.2-)0.3-0.8(-l) cm, (2.2-)2.5-5 times as long as wide, the venation except for dorsally prominulous midrib fully immersed or 4-6(-7) pairs of faint discolored but not prominulous secondary veins visible beneath; racemes 4-15(-19)-fld; sepals little graduated, the 2 outer ±4-6 mm, the longest inner one 5-8 mm; petals (7.5-)8-12.5 mm; filaments of 2 latero-abaxial stamens 3-7 mm, of the centric abaxial one 2-4 mm, the anthers of all 3 subequal, (3.5-)4-6 mm; ovary pilosulous laterally, the sutures glabrous; style 1.3-2.4 mm; ovules 8-20(-28); stipe of pod 2-4.5 mm, the body 3.5-7 x 0.75-1 cm, the seminal locules (2.5-)3-5 mm long. Collections: 26. [Key: "Anthers of 3 abaxial stamens all fertile, of ± equal length (4-7.8 mm) and girth even though the centric one is raised on a shorter filament than its neighbors; style 1.2-2.7(-3.4) mm. Lfts glabrous on upper, often nearly so on lower face, the margins and the midrib on dorsal face ciliolate; widespread along the Andes from Ecuador to Argentina. Plants of Peru s.-ward from 7°S, Bolivia and Argentina; filaments of longer abaxial stamens 3-11 mm; pod (0.75-)0.8-1.3(-1.5) cm wide. Range extending from s. Bolivia (Potosi, Tarija) to San Luis in Argentina; lfts thick-textured glabrous minutely ciliolate; stipe of pod 2-4.5 mm."]

    Distribution and Ecology - Dry mountain slopes, gravel washes, often near rock outcrops or among boulders, 2100-3700 m, locally plentiful along the e. slope and altiplano of the Andes from s. Bolivia (Potosi, Tarija) to Tucuman and La Rioja, Argentina, thence s.-e. to the pre-Andean ranges of Sas. de San Luis, del Morro and de Cordoba (Sa. Grande) in San Luis and Cordoba.—Fl. XII-III.

  • Discussion

    Bravo (1981, l.c.) records the use in Argentina of leaves, flowers and seeds of var. hookerana as purgatives and of the roasted seeds as surrogate coffee. She cites numerous vernacular names.

  • Distribution

    Potosí Bolivia South America| Tarija Bolivia South America| Tucuman Argentina South America| La Rioja Argentina South America| San Luis Argentina South America| Córdoba Argentina South America|