Apium
4 species in Aust. (1 naturalized, 3 native); all states and territories
Glabrous herbs with hollow grooved stems and divided leaves. Umbels compound, terminal or leaf-opposed, without involucral bracts or bracteoles. Flowers white. Sepals obsolete. Petals with inflexed apices. Fruit subglobular, laterally compressed; mericarps with 5 prominent ribs and 1 vitta under each furrow.