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.

SPHENOSCIADIUM

Species in genus: 1 sp
Etymology: (Greek: wedge umbrella, from umbel)

Native

S. capitellatum A. Gray

SWAMP WHITE HEADS, RANGER'S BUTTONS

Perennial, ± scabrous; root tuberous
Stem erect, 5–18 dm, generally branched, leafy
Leaf: petiole 1–4 dm; blade 1–4 dm, oblong to ovate, 1–2-pinnate or ternate then pinnate, leaflets 1–12 cm, generally ± lanceolate, acute, sparsely toothed to irregularly cut or pinnately lobed; cauline leaf sheaths conspicuously enlarged
Inflorescence: umbels compound, tomentose; peduncle 7–40 cm; bracts 0; bractlets many, linear, bristle-like; rays 4–18, 1.5–10 cm, ascending to reflexed; pedicels reduced to a disk; 2° umbels head-like, spheric
Flower: calyx lobes 0; petals obovate, white or purplish, tips narrowed; styles slender
Fruit 5–8 mm, wedge-shaped-obovate, very compressed front-to-back, tomentose; ribs unequally winged, marginal wider than others; oil tubes per rib-interval 1; fruit axis divided to base
Seed: face ± flat
Chromosomes: 2n=22
Ecology: Wet meadows, streamsides, lakeshores
Elevation: 900–3000 m.
Bioregional distribution: Inner North Coast Ranges, Cascade Range, High Sierra Nevada, Southwestern California, Great Basin Floristic Province
Distribution outside California: to Oregon, Idaho, Nevada, Baja California
Flowering time: Jul–Aug
TOXIC to livestock, but rarely eaten
Horticultural information: WET: 1, 2, 6, 7, 14, 15, 16; DFCLT.