ASTERACEAE

SUNFLOWER FAMILY

David J. Keil, Family Editor and author, except as specified

Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1–many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1–many per head
Flowers bisexual, unisexual, or sterile, ± small, of several types; calyx 0 or modified into pappus of bristles, scales, or awns, which is generally persistent in fruit; corolla radial or bilateral (rarely 0), lobes generally (0)4–5; stamens 4–5, anthers generally fused into cylinder around style, often appendaged at tips, bases, or both, filaments generally free, generally attached to corolla near throat; pistil 1, ovary inferior, 1-chambered, 1-seeded, style 1, branches 2, generally hair-tufted at tip, stigmas 2, generally on inside of style branches
Fruit: achene, cylindric to ovoid, generally deciduous with pappus attached
Genera in family: ± 1300 genera, 21,000 species (largest family of dicots): worldwide. Largest family in CA. Also see tribal key to CA genera: Strother 1997 Madroño 44(1):1–28. See glossary p. 25 for illustrations of general family characteristics.

CHAMOMILLA

Elizabeth McClintock

Annual, sometimes aromatic
Stems branched, erect or decumbent
Leaves alternate, irregularly 2–3-pinnately lobed; segments linear; petiole short or 0
Inflorescence: heads discoid, solitary or 2–3; receptacle conic, naked; phyllaries in 2–3 unequal series, margins scarious
Flowers many, yellow, tubular, 4-lobed, narrowed above; anthers very small, tips ovate, bases rounded or ± cordate; style short, branches truncate with shrub-like tips
Fruit cylindric, sometimes gelatinous when wet, ribbed; pappus a narrow crown or 0
Species in genus: ± 5 species: Eur, North America
Recent taxonomic note: *For revised taxonomy of Chamomilla, see Bremer & Humphries 1993 Bull Nat Hist Mus Lind (Bot) 23: 71–177
Etymology: (Derivation of name not known)
Reference: [Moe 1977 Dissertation, Univ CA, Berkeley]

Native

C. occidentalis (Greene) Rydb.

Plants 15–45(70) cm; herbage not strongly scented
Stems often branched only above
Leaves sessile, < 7 cm, glabrous
Inflorescence: heads generally < 1.5 cm diam, ± conic to spheric, remaining intact at maturity
Flowers: corollas 1–2 mm
Fruit angled, gelatinous when wet; tip and pappus crown 2-lobed, with wide brown gland extending from tip of each lobe to ± middle of achene
Ecology: Common. Undisturbed alkali flats, vernal pools, edges of salt marshes
Elevation: < 2400 m.
Bioregional distribution: Outer North Coast Ranges, High Cascade Range, High Sierra Nevada, San Joaquin Valley, San Francisco Bay Area, Outer South Coast Ranges, South Coast, Mojave Desert
Flowering time: May–Aug
Synonyms: Matricaria o. Greene
Recent taxonomic note: *Matricaria occidentalis Greene
Horticultural information: SUN: 5 , 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24; used as substitute for chamomile.