Sometimes a suffrutex with stems growing from a woody rhizome. Leaves may be opposite or alternate. The solitary flowers appear in the axils, and have a five-lobed calyx and corolla. The flower is tubular with four stamens, in pairs of unequallength. Each stamen has two divergent, oblong and curved thecae. The two-locular ovary has numerous ovules, and produces numerous seeds in a fruit capsule.