Annual, erect or ascending, prostrate herb with sparsely hairy branchlets; leaves ovate-lanceolate, base acute, margin entire, apex acuminate, sparsely hairy above and on nerves below; short petioled, stipules short, membranous with marginal bristles, inflorescence terminal or subterminal, many flowered, corymbose cymes; calyx tube short, teeth 4, triangular, subulate, acuminate much shorter than corolla tube, corolla tubular or funnel shaped, lobes 4, valvate, hairy outside, shorter than tube; stamens-4, inserted on the mouth of corolla, anthers included or exserted; ovary 2, rarely 3-4 celled; style filiform, stigma 2-4, linear, hairy outside; capsules sessile, subglobose, hispid, much broader than long, 2-valved, usually dehiscent, 2-4 seeded, compressed; seeds plano-convex or globose with a ventral cavity, pitted, black.