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©Copyright 1993 by the Regents of the University of California

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  • Up-to-date information about California vascular plants is available from the Jepson eFlora.

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.

LACTUCA

LETTUCE

G. Ledyard Stebbins

Annual to perennial herb; sap milky
Stems erect, 0.5–1.5+ m
Leaves basal and cauline, alternate, entire to pinnately lobed
Inflorescence: heads ligulate, many, in panicles; involucre cylindric; phyllaries in 2–several series; receptacle naked
Flowers few–many; ligules yellow or cream to blue, readily withering
Fruit flattened, short- or long-beaked; pappus of many bristles, falling separately
Species in genus: ± 100 species: ± worldwide temp
Etymology: (Latin: milky)

Introduced

L. saligna L.

Annual from taproot, 0.5–1(2) m
Stems decumbent or erect below, glabrous or bristly below
Leaves few–many, linear to lanceolate, entire or with linear lobes, clasping, glabrous or prickly-bristly on midvein
Inflorescence narrow, spike-like; branches and peduncles often appressed; heads in flower 4–5 cm wide; involucre in fruit 10–17 mm
Flowers 8–12; corolla pale yellow
Fruit 7–9 mm (including beak), brown, dark-mottled, rough, glabrous, several-veined on each face, unwinged; beak = or > body; pappus ± 6 mm, white
Chromosomes: 2n=18
Ecology: Waste, mostly urban places
Elevation: < 750 m.
Bioregional distribution: North Coast Ranges, s Sacramento Valley, Central Coast, San Francisco Bay Area, Outer South Coast Ranges
Distribution outside California: native to Europe

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