Senna siamea (Lam.) Irwin & Barneby, Mem. N.Y. Bot. Gard. 35 (1982)
Latin for 'from Siam', i.e. referring to Thailand.

Synonyms
Cassia florida Vahl, Cassia siamea Lam., Cassia sumatrana Roxb. ex Hornem, Senna sumatrana (Roxb. ex Hornem) Roxb.

Description
Understorey tree up to 20 m tall and 19 cm dbh. Stipules tiny, dropped early. Leaves alternate, compound, leaflets opposite, penni-veined, glabrous. Flowers ca. 27 mm diameter, yellow, placed in panicles. Fruits ca. 210 mm long, green-brown, elongate, dehiscent pods.

Ecology
Up to 100 m altitude on alluvial sites. Usually planted.

Uses
Ornamental shade tree.

Distribution
Originally from Burma, Thailand and Indo-China. Nowadays widely cultivated throughout the tropics. In Borneo collected in Central- and East-Kalimantan.