Suberect herbs. Leaves opposite or subfasciculate, stipules minute. In-florescence 3-flowered cyme on flattened, leaflike oblanceolate or broadly obovate peduncle. Flowers perigynous, sessile, the lateral flowers sterile, the central one fertile; bracteate, bracts erect, with uncinate spines. Sepals 4, erect, hooded at the apex, persistent. Petals absent. Stamens 4, free, antisepalous, filaments dilated and united at the base into a membranous cup; anthers minute, ovoid-oblong or subglobose, versatile. Carpels 2-3, syncarpous; ovary unilocular, with 1 basal semi-anatropous ovule; style filiform, 2-3 fid with 2-3 stigmas. Fruit a one seeded indehiscent utricle covered by the persistent sepals and bracts. Seed erect, endospermous; embryo straight with oblong cotyledons and inferior radicle.