Description from Flora of China
Trees or shrubs. Branchlets glabrous or pubescent but glabrescent. Leaves usually alternate, not stipulate; leaf blade papery to leathery, both surfaces usually pubescent when young but glabrescent when mature, sometimes abaxially glabrous and adaxially appressed pubescent, lateral veins conspicuous. Flowers in axillary clusters, sometimes with 2--4 bractlets. Sepals (4 or)5(or 6), outside pubescent, inside glabrous or sericeous, early deciduous or persistent in fruit. Corolla tubular to campanulate, 4- or 5--8-lobed, appendages absent. Stamens (4 or)5(--8), inserted in throat of corolla; staminodes less than 5 or 5--8, opposite sepals, lanceolate to subulate, sometimes scalelike to petal-like. Ovary conical, sometimes with cup-shaped disc at base, 5(or 6)-locular, ± villous. Fruit globose, glabrous or tomentose, sometimes setose; pericarp thin to thick, sometimes very hard when dry. Seed coat shiny, scar oblong to broadly ovate, covering half to nearly whole surface of seed.
About 50 species: tropical areas, mostly in America; two species in China.