Alstonia boonei De Wild.

Large deciduous tree to to 45 m tall and 1.2 m diameter; bole often deeply fluted to 7 m, buttresses present; bark greyish-green or grey, rough; slash rough-granular, yellowish, exuding a copious milky white latex; branches whorled. Leaves in whorls of 5-8, simple, subsessile to petiolate, stipules absent; petiole 2-10 (15) mm long, stout; blade oblanceolate to obovate, rarely elliptic, 7-26 x 3-9.3 cm; apex acute to rounded or sometimes emarginate; base narrowly cuneate; margins entire, sub-coriaceous to coriaceous, dark shiny green top surface, light green on under surface; midrib more prominent below. Inflorescence terminal, compound with 2-3 tiers of pseudo-umbels; primary peduncles 0.5-7 cm long, greyish pubescent; bracts ovate-triangular, 1-1.5 mm long, pubescent; pedicels about 5 mm long. Flowers regular, hermaphrodite, 5-merous; calyx cupular tube about 1 mm long; lobes ovate, about 1.5 mm long, spreading; corolla pale green tube up to 14 mm long; lobes slightly obliquely ovate, up to 6 mm long and wide, pubescent outside. Fruit formed by 2 pendent green follicles up to 60 cm long, longitudinally striate, dehiscing lengthways while on the tree; seeds numerous, flat, about 4 x 2 mm, with tufts of hair at each end 10 mm long.