Trees (rarely), shrubs or shrublets up to 4-5 m tall, evergreen or deciduous, glabrous, without dark glands; branching nearly always lateral. Stems 2-4-lined and ± compressed when young, sooner or later becoming terete, eglandular; cortex exfoliating in strips or scales; bark fissured, smooth. Leaves opposite, decussate, sessile to shortly petiolate, free, deciduous at basal articulation; lamina entire, with venation pinnate, open or usually closed, the tertiary almost absent (peripheral) or ± densely reticulate; laminar glands striiform to punctiform or rarely interrupted-linear, pale; marginal gland dots pale, dense; ventral resinous gland dots sometimes present. Inflorescence 1-25-flowered, branching dichasial/monochasial from 1-2(3) nodes, sometimes with subsidiary flowering branches from lower nodes; bracts and bracteoles foliar or reduced, not sepalline. Flowers stellate to cyathiform, homostylous. Sepals 5, free or very rarely united at the base (Sp. 19 in part), persistent, erect to reflexed in fruit, with margin entire or minutely denticulate or ciliolate; veins numerous; laminar glands pale, linear or interrupted to rarely punctiform; submarginal, inframarginal glands absent or pale; marginal glands absent. Petals 5, deciduous, with apiculus present, lateral to terminal, ± prominent or sometimes obsolete, margin entire or minutely denticulate or glandular-denticulate; marginal glands absent or amber; laminar glands ± numerous, pale, linear. Stamen fascicles 5, free, deciduous, each with c. 20-100 stamens; filaments united very shortly; anthers yellow to red, gland amber; pollen types I-IV. Ovary with 5 incompletely (or completely ?) axile placentae, ∞-ovulate; styles 5, free or partly united; stigma capitate to small and rounded. Capsule 5-valved, coriaceous, rarely fleshy at first (Sp. 5), not vittate. Seeds ± narrowly cylindric to fusiform or cylindric-ellipsoid, often carinate or laterally winged, with apical expansion sometimes wing- like; testa linear-reticulate to linear-foveolate.