Annual, up to 40 cm tall, erect branching, more or less villous and viscid. Leaves alternate, lanceolate or oblong-acute, sessile. Flowers conspicuous, in flat-topped leafy cymes; pedicels up to 1 cm. Calyx lobes 5-7 mm long, narrow, acute, spreading or recurving in fruit. Corolla salver-shaped, imbricate, twisted in bud, tube villous outside, c. 1 cm long, exceeding the calyx; colour and shape of the lobes quite variable. Stamens unequal. Capsule globular, 3 mm in diam., usually shed before dehiscing; seeds 3-5.