Erect or spreading annual or perennial. Leaves sessile or petiolate, opposite, upper alternate, simple, linear to lanceolate, entire to deeply lobed. Flowers axillary, solitary or few in fascicle, white, purplish or rosy, sometimes marked with yellow spots within, shortly pedicellate. Sepals 5, small, connate at the base, persistent or deciduous. Petals 5, connate into a tube; tube ventricose. Stamens included; anthers dorsifixed, sagittate; connective glandular on the top. Disc annular. Ovary 2 or 4 loculed due to false septum; ovules many in each locule. Fruit oblong or ovoid loculicidal capsule, 4-celled, 4-grooved, tetrangu¬lar, beaked at the apex. Seeds small, numerous, obliquely oblong, pyriform or obovate, with or without wings, smooth or rugose.