to perennial, small herbs. Stem ascending or erect and dichotomously branched.
Leaves opposite or whorled, ovate or oblong, stipules scarious. Inflorescence
terminal, dichasial cyme. Flowers small, bracts scarious. Sepals 5, keeled and
hooked. Petals 5, narrow, smaller than sepals, hyaline. Stamens 3-5, rarely 1.
Ovary unilocular, styles short, 3-lobed, stigmas 3, ovules many. Fruit capsule,
opening by 3 valves. Seeds many, ovoid.