Large deciduous tree up to 45 m tall, with latex; bole branchless for up to 25 m, up to 100(–140) cm in diameter, fluted at the base or with steep buttresses up to 4(–8) m high; bark smooth or rough, usually with large lenticels, greyish or pale brown, inner bark creamy or pale yellow, with copious latex; crown layered, with branches in whorls. Leaves in whorls of 4–8, simple and entire; stipules absent; petiole up to 2.5 cm long, flattened and grooved above, with narrowly triangular colleters at base; blade obovate, 6–20(–25) cm × 2.5–7.5 cm, cuneate to obtuse at base, rounded to shortly acuminate at apex, leathery, glabrous, many-veined with lateral veins joining near the margin. Inflorescence a terminal, compound, umbel-like cyme up to 23 cm long; peduncle 2–6(–13) cm long, stout; bracts up to 2.5 mm long. Flowers bisexual, regular, 5-merous, fragrant; pedicel 2–5(–7) mm long; sepals up to 2(–2.5) mm long, fused at base, pubescent; corolla cream-coloured or pale yellow, pubescent, with tube 5–14 mm long, narrowed around the middle, lobes obliquely ovate, 2.5–6 mm long; stamens inserted in upper part of corolla tube, filaments up to 1 mm long, anthers up to 1.5 mm long; ovary superior, ovoid, pubescent, 2-celled, style slender, 3–8 mm long, ending in a pistil head composed of a basal ring, a cylindrical central part and an elongate cleft stigmoid apical part. Fruit composed of 2 linear follicles 22–57 cm long and 2–4 mm in diameter, densely pubescent, many-seeded. Seeds oblong, flattened, 4.5–6 mm × 1.5–2 mm, brown, with long hairs up to 2 cm long on the ends.

Galactogogue and anthelmintic (bark)

PROTAbase: Alstonia boonei
AgroForestryTree Database

A bark decoction is widely used to treat malaria, typhoid fever, gonorrhoea, yaws, asthma and dysentery, and is also applied to sores, ulcers, exposed fractures, snakebites, rheumatic pain and toothache, and also to help delivery of placenta. A maceration of the bark is taken to treat jaundice, cough and sore throat, and is applied externally to treat skin complaints. An infusion of root and stem bark is drunk as a remedy for asthma; a liquid made from the stem bark and fruit is drunk once daily to treat impotence. The latex is applied to snakebites, skin complaints and swellings caused by filaria infections, and in concoction to treat fever. It is also said to be an antidote for Strophanthus poison. The leaves are applied topically to reduce oedemas and to treat sores.