Perennial herbs up to 0.75 m tall, with stems erect from branching rhizome, glabrous, without dark glands or, if present , then small, reddish or black, and marginal only. Stems incompletely 2-lined or usually terete, eglandular. Leaves opposite, perfoliate, persistent; lamina entire with venation pinnate, closed, the tertiary reticulation dense; laminar glands pale, small, punctiform, scattered; marginal gland dots irregular, small; ventral resin glands absent. Inflorescence 4-25-flowered with branching dichasial / monochasial from 1-5 nodes, without subsidiary branches; bracts and bracteoles persistent. Flowers stellate or with petals reflexed, homostylous. Sepals 5, free, persistent, erect in bud and fruit, with margin entire or minutely glandular; veins 5; laminar glands pale, linear or striiform to sometimes punctiform; marginal glands reddish to black or absent. Petals 5, persistent, without apiculus, entire or usually with minute sessile, reddish to black marginal glands; laminar glands pale, ± numerous, striiform to punctiform. Stamen fascicles 4 (united 2+1+1+1) or usually 3 (united 2+2+1), persistent, the single ones each with c. 20-25? stamens; filaments united at base only; anthers yellow, gland amber; pollen type IV. Ovary with 3(4) placentae, wholly united, ¥-ovulate; styles 3(4), free, appressed below; stigmas small. Capsule 3(4)-valved, coriaceous, with valves narrowly longitudinally vittate. Seeds ± curved-cylindric, not or slightly carinate, without apical expansion; testa shallowly and minutely foveolate.