Annual, erect, annual herb; corymbosely branched above, leaves alternate, sessile, simple, entire, elliptic-lanceolate, mucronate, 3-nerved, glabrous, without stipular glands; flowers 1-2 cm across, in axillary or terminal corymbs; sepals-5, membranous, ovate, acuminate, entire, glabrous, about half as long as petals, 3-nerved; petals 5, blue, slightly crenate, contorted, fugacious; stamens 5, usually alternating with minute staminodes, filaments united at the base, anthers versatile, 2-celled; glands-5 opposite the petals, usually adnate to the staminal ring; ovary entire, 5-celled, each with a false septum formed 10 locules, ovules 10, one in each locules, styles 5, usually free, stigma terminal, linear-clavate; capsule 10 seeded, hardly exceeding the sepals, septicidally splitting into 5, simple, 2-seeded or 10, 1-seeded cocci; seeds compressed, brown, smooth, ovate, beaked.