Annual herb, erect or procumbent, up to 15-25 cm high; branched from base; branches 4 angled, trailing or spreading, glabrous; leaves sessile, opposite, ovate-lanceolate, subacute at apex, glabrous; flowers axillary, solitary; pedicels 1-3 cm long, usually longer than petioles, recurved in fruits; sepals-5, almost equalling the petals, sepals narrow, lanceolate, acuminate, crenulate; corolla blue, lobes- 5, fringed with minute glands; stamens 5, attached to the base of the corolla, anthers globose, filaments villous; ovary unilocular, globose, ovules many, style filiform; capsules globose, circumciss; seeds flat or somewhat trigonous.