Shrub or small tree; stem and branches obtusely 4-angled, hairy; leaves usually opposite, palmately 3-5 foliolate, leaflets especially terminal petioluled, lanceolate, apex acute, glabrous above, covered with fine white tomentum beneath; flowers zygomorphic, in pedunculate, branched, white tomentose, large, terminal, pyramidal panicles; bracts minute, lanceolate, caducous; flowers small, white to violet, frangrant; calyx campanulate, shortly 5-toothed; teeths acute; corolla 2 lipped, subequally 5 lobed, tomentose, blue, pink or purple; stamens-4, didynamous, usually exserted, anther cells parallel at first, divaricate or twisted afterwards, filaments slender; ovary 2-4 celled, 4-ovuled, style filiform, stigma shortly bifid; drupes of 4-pyrenes, globose, supported by persistent, enlarged calyx; seeds obovate or oblong.