Senna hirsuta
Content
Description
Herb up to 2 m high, erect, hairy, stinking; young branches grooved.
Leaves with 3-7 pairs of leaflets; petiole stout, 3-6 cm with a sessile, ovoid-oblong gland near the insertion; rachis 7-10 cm, glandless, produced beyond the upper petiolules into a stout, 2 mm long mucro.
Stipules linear, acute, early caducous.
Sepals, 2 outer small, ovate to obovate, rounded, c. 5 mm; 3 inner more or less puberulous, similar but larger, 7-8 mm.
Petals yellow, obovate, short-clawed, 14-17 mm long.
Stamens 10: 2 largest with filaments 3-6 mm long, flat, winged, anthers curved, 6-8 mm, beaked, opening by apical pores; 4 similar but only half as long; 1 equal to these but with a narrow anther; staminodes 3.
Ovary hairy (hirsute or strigose), subsessile; the style short, glabrous; stigma small, subapical.
Seeds 50-100, flat, olive, obovoid, 3-4 mm long.
Distribution
Old World tropics present, tropical South America present
Origin tropical South America; long naturalized as a weed in the Old World tropics..
Taxonomy
De Wit (1956) recognizes two closely related species, Cassia hirsuta and C. leptocarpa, the first as a weed from Malaysia and Indonesia, the last only from the Philippines. Irwin and Barneby (1982) have combined several species under Senna hirsuta which is an extremely variable species in which they recognize 7 varieties, mainly separated on variations in the indumentum and on the shape of the pod; whether it is possible to maintain them shall not be judged here; some of the varieties are based on very few collections. Var. puberula, however, of which C. leptocarpa is a synonym, seems rather distinct from the typical var. hirsuta.
Citation
Verdc. 1979 – In: Manual New Guinea Leg., Lae Bot. Bull.: 45
Irwin & Barneby 1982 – In: Mem. N.Y. Bot. Gard.: 425.
Rudd 1991 – In: Fl. Ceylon: 76.
de Wit 1956 – In: Webbia: 251.
Ridley 1922 – In: Fl. Malay Penins.: 618
K. & S.S. Larsen 1980: p. 92. – In: Fl. Camb., Laos & Vietnam: pl. 16/1
K. & S.S. Larsen 1984: p. 113. – In: Fl. Thailand: f. 28/1