Eurycoma longifolia Jack, Mal. Misc. 2 (1822)
Latin for 'long leaves'.

Synonyms
Eurycoma eglandulosa Merr., Eurycoma longifolia var. cochinchinensis King, Eurycoma longifolia var. merguensis King, Eurycoma merguensis Planch., Eurycoma tavoyana Wall., Manotes asiatica Gagnep., Picroxylon siamense Warb.

Description
Understorey tree up to 16 m tall and 20 cm dbh. Stipules absent. Leaves alternate, crowded at tree tip, compound, leaflets opposite to alternate, penni-veined, but venation barely visible, glabrous. Flowers ca. 7 mm diameter, pink-red-purple, placed in panicles. Fruits ca. 14 mm long, red-purple, fleshy capsules.

Ecology
In undisturbed mixed dipterocarp and keranga forests up to 500 m altitude. On hillsides and ridges with sandy to clay soils. In secondary forests usually present as a pre-disturbance remnant.

Uses
The roots are used as a male aphrodisiac. The bark and roots are used against malaria, fevers, intestinal worms. Also as a tonic after childbirth.

Distribution
Indo-China, Burma, Thailand, Peninsular Malaysia, Sumatra, Borneo (throughout the island), Philippines.

Local names in Borneo
Bedara, Ionadiandau, Nuad-mandau, Pait-pait, Sengkanyat, Sengkayap, Tombuid, Tongkat ali, Tongkat langit.