Annual, 5-40 (-50) cm long, branched or ± simple, spreading, erect herb. Leaves basal as well as cauline. Basal leaves 0.5-2.5 x 0.25-1.0 cm, lanceolate, elliptic-ovate, acute or acuminate, entire. Cauline leaves 0.5-23 x 0.25-1.0 cm, elliptic-lanceolate, acute-acuminate, entire. Inflorescence dichasial cyme, many flowered. Flowers 0.8-13 (-13) cm long, pedicellate; pedicel 0.2-03 cm long. Calyx tubular, reaching the length of corolla tube or sometimes shorter; tube shorter than lobes, 2-4 mm long; lobes 5-8 x 1-2 mm, linear, acuminate, unequal. Corolla tubular, white, pink-purple; 0.8-13 cm long; tube longer than lobes, 0.6-1.0 cm long; lobes 0.4-0.7 x 0.2-0.4 cm, ovate-lanceolate, obtuse, entire. Stamens 5, filaments inserted in ± middle of corolla tube; anthers basifixed. Ovary 5-8 x 1-2.5 mm, oblong-lanceolate; stigma 2-lobed. Capsules oblong, sessile, included. Seeds numerous, minute, globose.