Corolla 5-lobed; tube funnel-shaped or subcylindric, straight, longer than calyx; lobes spreading, almost flat, imbricate in bud.
Leaves opposite, verticillate or scattered, sessile to shortly petiolate, entire or toothed in upper half.
Ovary bilocular, ellipsoid; ovules many; stigma capitate, globose or ovoid; style thick, linear.
Calyx 5-partite, campanulate, lobes ovate, elliptic or lanceolate, imbricate in bud.
Seeds discoid, with membranous testa and winged margin.
Inflorescence of terminal and axillary cymes.
Fruit bilocular, ovoid, capsular.
Shrubs or subshrubs.