Erect puberulous or glabrescent herbs. Rhizome short, creeping. Aerial stem annual, simple or branched. Leaves cauline, alternate, flat, with several veins and a strong midrib, sessile, entire, lanceolate to ovate, with a sheathing base. Inflorescence terminal, racemose, simple or branched, or flowers in the axil of vegetative leaves. Pedicels solitary, not articulated. Perianth segments free or very shortly united, equal or subequal but the outer three saccate at the base, erect to spreading. Filaments flattened, more or less connivent, free of the perianth; anthers dorsifixed, versatile, oblong, extrorse. Ovary superior, sessile, oblong, 3-celled, 3-angled; ovules axile, numerous; style columnar; with 3 spreading or recurved bifid branches. Capsule septicidal. Seeds oblong or ovoid.