Plants annual, prostrate. Stems longitudinally 3-winged. Leaves alternate. Flowers 1-3 on extremely short branches, sessile or shortly pedicellate. Calyx epigynous, 5-lobed, lobes dentate. Corolla epigynous, tubular-campanulate, 5-lobed. Stamens 5, free from corolla and free from each other; filaments slightly dilated and sparsely ciliate at base. Ovary inferior, 3-locular; stigma 3-fid; lobes linear, recurved. Fruit dry, irregularly dehiscent or irregularly poricidal in lower part. Seeds ellipsoid, not angular, shallowly reticulate.