Author: (Linnaeus) Roxburgh
Morphological description (sophera Senna compl FT28 )
Erect, almost glabrous shrub , 1-2(-3) m high. Stipules ovate, more or less glabrous, c. 5 mm long, caducous.
Leaves paripinnate with 4-10 pairs of leaflets; petiole 3-5 cm long with a thin, subulate or narrowly clavate gland, 5-10 mm above the petiole joint. Leaflets lanceolate, on a slender, 2 mm long petiolule , apex acute, base rounded, 2-5(-8) by 1-2 cm, the upper leaflets largest.
Inflorescences axillary, few-flowered corymbs; peduncle 1-2 cm; bracts ovate, 5 mm long; bracteoles absent; pedicels 1-1.5 cm.
Flower: Sepals 5, ovate-rounded, 5 mm long. Petals 5, yellow, obovate, 10-14 by 6-8 mm, short-clawed. Stamens: 2 with filaments 5-7 mm long, anthers 5-6 mm long opening by apical pores; 4 shorter with filaments 2 mm and anthers 5 mm, opening the same way; staminodes 3-4, c. 2 mm; filaments of all stamens straight. Ovary finely pubescent; style thin, glabrous; stigma slightly dilated, strongly incurved.
Pods erect, straight or nearly so, cylindric (swollen) or linear-ellipsoid, 6-10 by 0.5-1 cm, sutures not prominent.
Seeds 30-40 ovoid, compressed, 3-4 mm.
Distribution
Origin neotropic, now found throughout the tropics. It seems not to be equally common in all parts of Malesia ; it is evidently not so frequent on the Malay Peninsula and in the Philippines, but this may be due to lack of collections.
Habitat
Roadsides, old fields, ditches, waste places and around and in villages, usually at lower altitudes.
Uses
Locally used for medicinal purposes. See Heyne (1950: 747); Quisumbing (1951: 384).
Note
Often confused with Senna occidentalis . The narrower leaves and the narrow, thin, petiolar gland separate the two species.