Annual, erect, glabrous or sparsely hairy herb; lower leaves radical in rosette, oblanceolate or obovate, upper leaves opposite, obovate or oblong, serrate or dentate, shortly petiolate; flowers very small, white, pubescent, in terminal racemes; calyx lobes-5, ovate-lanceolate, subulate; corolla white, beared with club-shaped hairs, 2-lipped, tube short, upper lip erect, bifid, lower much larger, spreading, 3-fid, throat with 2-lobed palate; stamens 4, didynamous, included; anther cells 2, contiguous; ovary 2 celled, ovoid, style dilated at the top, stigma 2-lobed; capsule subglobose or oblong, compressed, loculicidal, included in the persistent calyx; seeds minute, pale yellow.