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.

CICUTA

WATER HEMLOCK

Perennial, glabrous; rhizome divided internally into chambers, with sap that oxidizes to reddish brown, bearing fibrous or tuberous roots
Stem erect, hollow
Leaf: blade oblong to triangular-ovate, 1–3-pinnate or ternate-pinnate, leaflets linear to ovate-lanceolate, serrate or irregularly cut
Inflorescence: umbels compound; bracts generally 0; bractlets generally inconspicuous; rays, pedicels many, spreading
Flower: calyx lobes minute; petals wide, white, tips narrowed
Fruit ovate to round, slightly compressed side-to-side; ribs low, corky, sometimes unequally spaced; oil tubes per rib-interval 1; fruit axis divided to base
Seed: face flat or concave
Species in genus: ± 4 species: Eurasia, North America
Etymology: (Ancient Latin name)
Reference: [Mulligan & Munro 1981 Canad J Plant Sci 61:93–105]
More evidence from ripe fruit and chromosomes needed to substantiate proposed cryptic species TOXIC: both species below contain cicutoxin, a virulent poison; many livestock and human deaths recorded. The most lethally toxic native plants.

Native

C. maculata L.

Plant 10–15 dm
Leaf 1–4 dm, ovate to triangular-ovate, 1–2-pinnate; leaflets 2–10 cm, lanceolate, acute or acuminate, coarsely to sparsely serrate, areas surrounded by veins on lower surface fine, generally rounded or square
Inflorescence: umbels compound, terminal and lateral; peduncles 2.5–12 cm; rays 15–30, 2–4.5 cm; pedicels 15–30, 2–10 mm
Fruit 3–4 mm, generally ovate; ribs generally as wide as to much narrower than intervals between
Chromosomes: 2n=22
Ecology: Wet places
Elevation: < 2000 m.
Bioregional distribution: s Sacramento Valley (Suisun Marshes), Central Coast, South Coast, San Bernardino Mountains, Great Basin Floristic Province
Distribution outside California: to Alaska, c Mexico
Varieties distinguishable in CA chiefly by habitat, geog.