An annual or perennial herbs or small subshrubs; stems prostrate or erect, usually 4-angled, glabrous to hispid or scabrid. Leaves are opposite or pseudowhorled, usually lanceolate to ovate or elliptic, sessile or petiolate, stipules adnate to petioles, forming a sheath, margins with 1 to numerous filiform setae. Flowers usually small, perfect, sessile, in axillary or terminal, usually many-flowered clusters subtended by 1-2 or more pairs of bract-like leaves, stipule-derived bracteoles with setae; hypanthium obovoid, turbinate, or sometimes with intermediate teeth; corolla funnelform or salverform, the tube usually very slender, the lobes (3) 4, spreading, valvate in bud; stamens 4, inserted on corolla tube or throat, usually exserted; ovary 2-celled, ovules 1 per cell, attached to middle of septum; style filiform, exserted. Fruit either a 2-walved capsule dehiscing from apex downward and the septum disappearing, or of 2 dimorphic mericarps, one dehiscent, the other indehiscent. Seeds 2, usually glossy brown, oblong, ellipsoid, or ovoid, usually reticulate, ventrally grooved.

PROSEA (Plant Resources of South-East Asia) Foundation
Pacific Island Ecosystems at Risk (PIER)

Applied in a poultice for headache (leaves); applied to wounds (crushed leaves); to treat eczema, worms and ringworm (plant sap)