The Apiaceae are aromatic herbs, shrubs, trees, or occasionally lianas; stems often hollow in internodes; basic unit of inflorescence usually an umbel or less commonly a head, these simple or distributed in umbels, racemes, spikes, or panicles. The family includes about 460 genera and 4,250 species. The leaves are nearly always alternate and pinnately or palmately compound or more than once compound, occasionally simple, but even then usually deeply dissected or lobed; petioles are often sheathing; stipules are present or absent. The flowers are typically small, mostly bisexual, mostly actinomorphic except in a few instances where pseudanthia are produced and the peripheral flowers have enlarged petals directed away from the center of the inflorescence. The calyx is reduced to 5 (occasionally more) tooth-like sepals around the summit of the ovary or may even be obsolete. The corolla consists of 5 (occasionally more) distinct or sometimes irregularly coherent, typically inflexed petals, or rarely the corolla is lacking. The androecium comprises distinct stamens equaling in number and alternating with the petals and arising from an epigynous nectary disk. The gynoecium consists of a single compound pistil of 2-15 carpels, an equal number of styles or these connate into one style, and an inferior ovary with 2-15 locules, each bearing a single pendulous, axile ovule. An epigynous nectary disk is generally confluent with the enlarged stylar base (stylopodium). The fruit is a berry or drupe that sometimes splits into one-seeded segments ("Aralioids"), or a specialized schizocarp that splits into two 1-seeded segments ("Apioides").
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