Herbs or subshrubs, erect or decumbent. Stipules small, inconspicuous caduceus. Leaves sometimes have irregular purplish blotches on the midvein. Pedicels without articulation. Inflorescence solitary in leaf axils or aggregated in open apical racemes or panicles. No epicalyx. Calyx with 5-10 costae, cupulate. Petals white, yellow or purple; spreading. Staminal column antheriferous at apex, styles and mericarps 5-20. Mericarps single celled and single seeded, sometimes with spines (this includes the commonest most wide spread species A. cristata). No endoglossum.