Apiaceae

Abstract

Annual, biennial or perennial, monocarpic or polycarpic, caulescent or acaulescent, glabrous or pubescent or glandular-pubescent herbs, rarely suffrutescent or woody subshrubs, shrubs or trees, evergreen or deciduous; with taproots, rhizomes, or unbranched to branched rootstocks, sometimes swollen and tuberiform; with schizogenous secretory canals throughout the plant. Stems erect, ascending, decumbent, prostrate or rarely creeping; branched or unbranched; with multilacunar (or rarely trilacunar) nodes, internodes sometimes fistulose. Leaves alternate, rarely opposite or verticillate; petioles usually present and typically sheathing at base, often inflated, without (or rarely with) stipules; blades ternately or pinnately compound, or pinnately, ternately, or palmately lobed, or simple and entire to toothed, to deeply divided, rarely sessile or perfoliate; venation pinnate or less commonly palmate or parallel. Plants andromonoecious or hermaphroditic, rarely gynodioecious to dioecious. Inflorescences compound-umbellate (less commonly simple-umbellate, capitulate or cymose), arranged in cymose or racemose synflorescences; umbels typically subtended by an involucre of one to many bracts at the base of the rays (secondary axes), bracts entire or dissected, or lacking; umbellules typically subtended by involucel of one to many bracteoles at the base of the pedicels, bracteoles entire or dissected, or lacking. Flowers perfect or staminate (rarely functionally pistillate), epigynous, actinomorphic (or outer flowers of the umbel or umbellule zygomorphic). Perianth and androecium 5-merous (rarely 5–6-merous). Calyx lobes linear to lanceolate, triangular, or ovate, sometimes spiny or pinnatisect, or small to obscure. Petals valvate, usually basally clawed and having a narrowed, inflexed apex (less commonly with broad insertion and/or lacking the inflexed apex), sometimes lobed (or shortly notched to deeply bifid), dorsally glabrous or puberulent; sometimes with one to several secretory ducts. Stamens alternate with the petals; anthers dorsifixed or basifixed, tetrasporangiate, dehiscing by longitudinal slits; filaments filiform, inflexed in bud. Ovary syncarpous of 2 carpels (rarely 1 or 2–4), each carpel unilocular with apical to axile placentation; stigmas on stylodia; stylodia distinct, rarely connate, frequently reflexed in fruit, usually swollen at the base to form a nectariferous disc or stylopodium. Ovules anatropous, pendulous, two per locule (but one always abortive), unitegmic, tenuinucellate or pseudocrassinucellate. Fruits dry (rarely fleshy), usually schizocarpic with two mericarps attached by a commissural face, usually with a bifurcated or entire carpophore (becoming free from or remaining fused to the mericarps at maturity); fruits with filiform, keeled, corky, winged, dentate, spiny or obscure ribs formed over the vascular bundles (primary ribs), and sometimes formed in the furrows or valleculae (secondary ribs); one or more secretory canals found in association with the vascular strands (rib oil ducts, sometimes obscure) and/or in the valleculae and commissural face (vittae, sometimes arranged cyclically); endocarp parenchymatous (soft to lignified) or sclerified. Seeds straight, endosperm at commissural face plane to deeply concave or sulcate, copious and oily; embryo minute but often well differentiated.