Description from Flora of China
Trees 8-45 m tall, buttressed. Branchets 4-angled, becoming terete with age; ultimate branches pendulous. Leaves shortly petiolate, opposite, oblong to ovate or lanceolate, leathery to papery, glabrous, secondary vein pairs numerous, joined in a series of intramarginal arches, base rounded to cordate, apex acute to acuminate. Inflorescence of few to many flowers in a lax, terminal corymb. Flowers actinomorphic, bisexual, usually 4- or 6-merous, but variably 4-8-merous on same or different individuals. Floral tube obconic or broadly campanulate, persistent in fruit; sepals 4-8, triangular-ovate, thick. Petals 4-8, broad, crinkled, shortly clawed. Stamens 12 or 24-50+; filaments filiform-subulate from a broadened base, long; anthers recurved or replicate over one end of connective. Ovary semi-inferior; ovules numerous; style long-exserted, slender; stigma capitate to slightly 4-lobed. Fruit indurate capsules, partially surrounded by persistent floral tube, oblong to ovoid-globose, loculicidally deeply dehiscent, 4-9-valved. Seeds numerous, filiform, fragile, 2-tailed. 2n = 48.
The species are trees of lowland rain forests.
Two or three species: evergreen rain forests of SE Asia; two species (one cultivated) in China.
(Authors: Qin Haining (覃海宁); Shirley Graham)