Senna sulfurea
Content
Description
Large shrub or small tree, 2-6 m tall; young parts strigulose later glabrous.
Leaves with 4-6 pairs of leaflets; petiole 3-5.6 cm; rachis 5-15 cm with a clavate gland, 1-2 mm long, between the 2 or 3 (or 4) lower pairs of leaflets.
Stipules linear falcate, 6-15 mm long.
Inflorescences lateral racemes with peduncles 3-10 cm, axis 1-6 cm; bracts ovate acute, 3-8 mm long, finally reflexed; pedicels 1-3 cm.
Sepals green to reddish brown, 2 outer suborbicular c. 3 mm, the 3 inner obovate, increasing to 6-9 mm in length.
Petals bright yellow (drying orange or pinkish brown), ovate-obovate, 1.5-2 cm long, with a narrow claw 1-1.5 cm long.
Stamens 10 fertile with thick, short filaments, 1-4 mm; anthers subequal 5-7 mm long, opening apically by short slits.
Ovary strigulose; style glabrous, filiform; stigma inconspicuous.
Seeds 20-30, oblong-elliptic, c. 7 by 4 mm.
Distribution
Asia-Tropical: India, Burma, neotropics present
The species is native to India and Burma. Now also naturalized in the Neotropics.
Taxonomy
This species and Senna surattensis belong to sect. Psilorhegma (Vogel) Irwin & Barneby (l.c.: 77); a full account of the intricate nomenclature of these two taxa is given there.
We do not maintain forma ferox de Wit, known only from two collections. It may be an ecotypical deviating form as suggested by the author.