Annuals with stiff opposite leaves. Flowers perfect, 5-merous, bracteolate. Perianth free nearly to the base, 2 or 3 of them with wing-like protuberance in fruit. Stamens 5, inserted on a fleshy lobed hypogynous disc; anthers with narrow sublinear appendages. Ovary with a short style and 2 stigmas. Fruit vertical; seeds vertical, with spiral embryo and radicle pointing upwards.