Herbs with simple, alternate, opposite or whorled leaves. Stem often succulent and swollen at the nodes. Flowers irregular, bisexual, often showy. Sepals 3(-5), the lowermost large and spurred. Petals 3-5, the anterior (posterior in mature flowers) larger, the lateral ones fused in pairs, lowermost often 2-lobed. Stamens 5; anthers adnate, forming a hood around the ovary. Ovary 5-locular, syncarpous. Capsule fleshy, with an explosive dehiscence for seed ejection.

Allied to the Geraniaceae from which it differs in the irregular flowers, the spurred lower sepal and the anthers connate to form a hood or a ring around the ovary.