Senna sulfurea

Senna sulfurea (DC. ex Collad.) H.S. Irwin & Barneby, Mem. New York Bot. Gard. 35: 78. 1982; Fl. China @ eFloras.org:10. 31; S. surattensis (Burm. f.) Irwin & Barneby, Mem. New York. Bot. Gard. 35(1):81.1982; S. surrattensis (Burman) Irwin & Barneby subsp. glauca (Lam.) Zhu; Cassia glauca Lam., Encycl. 1: 647. 1785; Thwaites, Enum. Pl. Zeyl. 96.1859; Baker in Hook. f., Fl. Brit. Ind. 2: 235.1879; Trimen, Handb. Fl. Ceylon 2: 109.1894; C. sulfurea DC. ex Collad., Hist. Nat. Med. Classes, 84. 1816; C. surattensis Burman subsp. glauca (Lam.) K. & S. Larsen, Fl. Cambodge, Laos & Vietnam, Legum. Caesalp. 102. 1980; Rudd. in Dassanayake & Fosberg (eds.), A Revised Handbook to the Flora of Ceylon. Vol. 7.1991;

Shrubs, large or small trees, up to 7 m. Young shoots pilose, later glabrescent. Leaves 15-30 cm with a clavate gland (1-3 mm) on rachis between each of lowest 2-4 pairs of leaflets, sometimes 1 or 2 glands on petiole also; rachis with adaxial channel and extending beyond leaflets in the form of mucro; stipules 1-1.5 cm long, linear, falcate, caducous or subpersistent; petiole 3.5-5.5 (-6.5) cm; leaf base pulvinate; petiolules ca. 3 mm; leaflets 4-6 (-10) pairs, usually 5 pairs, abaxially pubescent, adaxially greenish and glabrous, , 3.5-10 cm x 2.5-5.5 cm, ovate or elliptic, base broadly cuneate or subrounded, slightly oblique, apex obtusely rounded or emarginate. Stipules, petiole, rachis, petiolules, glands and abaxial surface of leaflets pubescent. Corymbose racemes in axils of leaves in upper parts of branches, 10-20 flowered; flowers zygomorphic, bisexual, pentamerous, perigynous, showy, yellow; peduncle 3-10 cm; rachis 1-6 cm; bracts ovate, 3-8 mm, apex acute, finally reflexed, caducous or subpersistent. Pedicels 1-3 cm. Sepals green to reddish brown, margin ciliolate otherwise glabrous, unequal: outer 2 suborbicular, ca. 5 mm x 3 mm, inner 3 obovate, 8-11 mm x 6-9 mm, Petals bright yellow (drying orange or pinkish brown), ovate or obovate, 1.5-2.5 cm x ca. 1.1 cm, 5-veined, puberulent abaxially, clawed, claw short, 1.5 mm long. Stamens 10, all fertile, with short thick filaments ( 1-6 mm long ), lowest (abaxial or anterior) 3 with longer filaments; anthers subequal ( 5-8 mm long ), opening by short apical slits. Ovary ca. 1.5 cm long, stipitate, stipe ca. 5 mm long, hairy, unilocular with many ovules, placentation marginal; style glabrous, ca. 5 mm long; stigma simple. Legumes glossy, thin, compressed, straight, strap-shaped, with raised lines between seeds, dehiscent, 10-20 cm x 1.2-1.8 cm with slender beak on top and 1-2 cm long stipe at base, valves papery. Seeds 20-37, transverse, blackish, glossy, compressed, oblong-elliptic, ca. 7 mm x 4 mm, with an areole on each face.

Flowering and Fruiting: August to January
Common Names: Glaucous Cassia, Glossy Shower Senna, Golden Senna, Singapore Shower, Smooth Senna, Sulphur Cassia, Sulphur-Flowered Senna, Sunshine Tree