APIACEAE

CARROT FAMILY

Lincoln Constance

Annual, biennial, perennial herb (rarely shrub, tree), often from taproot
Stem often ± scapose, generally ribbed, hollow
Leaves basal and generally some cauline, generally alternate; stipules generally 0; petiole base generally sheathing stem; blade generally much dissected, sometimes compound
Inflorescence: umbel or head, simple or compound, generally peduncled; bracts present (in involucres) or not; bractlets generally present (in involucels)
Flowers many, small, generally bisexual (or some staminate), generally radial (or outer bilateral); calyx 0 or lobes 5, small, atop ovary; petals 5, free, generally ovate or spoon-shaped, generally incurved at tips, generally ± ephemeral; stamens 5; pistil 1, ovary inferior, 2-chambered, generally with a ± conic, persistent projection or platform on top subtending 2 free styles
Fruit: 2 dry, 1-seeded halves that separate from each other but generally remain attached for some time to a central axis; ribs on each half 5, 2 marginal and 3 on back; oil tubes 1–several per interval between ribs
Genera in family: 300 genera, 3,000 species: ± worldwide, especially temp; many cultivated for food or spice (e.g., Carum, caraway; Daucus; Petroselinum); some highly toxic (e.g., Conium). Underground structures here called roots, but true nature remains problematic. Mature fruit generally critical in identification; shapes generally given in outline, followed by shape in X -section of 2 fruit halves together.

CONIUM

POISON HEMLOCK

Biennial, taprooted; herbage glabrous, musty-scented
Stem erect, branched
Leaf: blade ovate to triangular-ovate, pinnately dissected or compound, segments or leaflets lanceolate or oblong to ovate, serrate to 1–2-pinnately lobed
Inflorescence: umbels compound, terminal and lateral; bracts, bractlets small, few; rays, pedicels ± many, spreading-ascending
Flower: calyx lobes 0; petals wide, white or yellowish, tips narrowed
Fruit ovate to round, slightly compressed side-to-side; ribs subequal, low; oil tubes per rib-interval 0; fruit axis divided to base
Seed: face grooved
Species in genus: ± 6 species: Eur, s Africa. TOXIC: contains highly toxic alkaloids used in ancient Greece for capital punishment (e.g., Socrates); many human deaths, rarely eaten by livestock
Etymology: (Greek name used by Dioscorides)

Introduced

C. maculatum L.

Plant 5–30 dm
Stem generally purple-spotted or -streaked
Leaf: petiole dilated; blade 1.5–3 dm, widely ovate, generally 2-pinnate
Inflorescence much-branched; peduncles 2–8 cm; bracts 4–6, acuminate; bractlets 5–6, 1.5–2 mm, like bracts, generally ± fused at base, scarious; rays 10–20, 1.5–5 cm
Fruit 2–3 mm wide, ovate; ribs generally wavy
Chromosomes: 2n=22
Ecology: Common. Moist, especially disturbed places
Elevation: generally < 1000 m.
Bioregional distribution: California Floristic Province
Distribution outside California: America; native to Europe