Habit annual, biennial or perennial herbs. Leaves basal or alternate, rarely simple, usually pinnately or ternately divided; petioles usually with a sheathing base clasping the stem, often broadly so; mainly exstipulate. Flowers small, borne in simple or compound umbels, rarely in compact heads, hermaphrodite or sometimes male, 5-merous. Rays of umbels sometimes subtended by a whorl of bracts (involucre); pedicels of umbellules often subtended by a whorl of bracteoles (involucel). Calyx tube wholly fused to the ovary, the teeth free, conspicuous to obsolete, persistent or not in fruit. Petals free, with or without inflexed apex, regular or outer petals enlarged and radiant. Stamens alternating with petals and borne on nectary disc. Ovary of 2 carpels united to form an inferior bilocular ovary; styles distinct, usually swollen at base to form the stylopodium. Fruit a dry schizocarp consisting of 2 subterete or compressed mericarps joined by their faces (commissure); mericarps separating at maturity and attached at apex to a slender, entire to deeply bifid, carpophore (carpophore rarely absent); mericarps smooth to variously ornamented with hairs, bristles or spines, usually with 5 primary vertical ribs or ridges (additional secondary ridges sometimes also present), ridges sometimes prominent or winged; vittae (oil tubes) usually present within mericarp wall and sometimes visible between ridges.
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Total: 41 Genera, 95 Species
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