An annual procumbent herb. Stem diffuse. Leaves usually opposite, exstipulate, with embedded raphides. Flowers small, in axillary cymes or fascicles. Sepals 5. Petals absent. Stamens 5 or more. Carpels usually 5, free; ovary unilocular, with a single basal ovule. Fruit indehiscent, of usually 5 one seeded parts. Seeds more or less reniform.