Shrubs, shrublets or wiry to soft herbs up to 2.5 m tall, deciduous when woody, glabrous or with simple hairs, with dark (black) glands nearly always on leaves (sometimes all pale in Sp. 15), usually on sepals and anthers and sometimes on petals and stems (black or rarely red); branching below inflorescence lateral. Stems 4-lined and ancipitous or 2-lined at first or wholly terete, eglandular or rarely red- or black-gland-dotted; cortex exfoliating in strips or sheets; bark smooth and finely striate, sometimes flaking irregularly. Leaves opposite or very rarely and abnormally 3-whorled, decussate, sessile or rarely very shortly petiolate, free, deciduous at base or persistent; lamina entire or rarely undulate to serrulate with prominent glands, with venation pinnate, open (laterals ending freely) or closed (upper or all laterals incurved and uniting), with tertiary venation densely reticulate; laminar glands punctiform; marginal gland-dots dense or rarely sparse; ventral glands absent. Inflorescence1-c. 200-flowered, with branching dichasial (first node) then monochasial, from 1-8 nodes often with subsidiary branches from lower nodes; bracts and bracteoles reduced, transitional in form to sepals. Flowers stellate, homostylous. Sepals 5, free or up toc. 0.2 united, persistent, erect in fruit, with margin subentire to glandular-denticulate or -ciliate; veins 3-7; laminar glands pale and/or black, linear to punctiform,; marginal and/or inframarginal glands black,when marginal often flat-topped. Petals 5, persistent and twisting together round developing capsule or occasionally separately,with apiculus present, subapical or apical, acute to apiculate, or absent, margin with ± prominent glands or entire; marginal glands black or absent; laminar glands pale, linear to punctiform and/or black, punctiform to elongate-punctiform. Stamen fascicles 5, united 2+2+1 (i.e. 3 ) or rarely 2+1 + 1 + 1 (i.e. '4') but sometimes indistinct, persistent, totalling c. 20-70 stamens; filaments united very shortly; anthers yellow, gland black or very rarely amber; pollen types I, X. Ovary with 3 loosely to completely axile placentae, each ∞-ovulate; styles 3(4), free with bases discrete; stigmas scarcely capitate or usually small. Capsule 3(4)-valved, subcoriaceous to chartaceous, with valves narrowly longitudinally vittate. Seeds narrowly cylindric, not or scarcely carinate, with apical expansion; testa almost smooth or shallowly linear-reticulate to linear- foveolate or finely scalariform.