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©Copyright 1993 by the Regents of the University of California
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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.


Annual or perennial herb
Stems generally erect, leafy
Leaves alternate, linear to ± (ob)lanceolate, entire to pinnately dissected, obtuse to acute
Inflorescence: heads generally disciform (or minutely radiate), generally many in raceme- or panicle-like clusters; phyllaries in 2–3 equal or unequal series, free, linear to lanceolate, often narrowly scarious-margined, reflexed in age; receptacle naked
Pistillate flowers generally many; corollas white, pink, or cream, narrowly cylindric
Disk flowers ± few; corollas generally yellow, lobes short-triangular; style tips lanceolate, included or short-exserted
Fruit elliptic, compressed, puberulent; pappus of bristles
Species in genus: ± 50 species: especially tropical
Etymology: (Greek: flea; name of Pliny & Dioscorides for a fleabane)
Descended from within Erigeron [Noyes 2000 Plant Syst Evol 220:93–114]


C. canadensis (L.) Cronquist


Annual 1–20(30) dm
Stem generally simple below, much-branched above, strigose or stiff-spreading-hairy
Leaves 1–10 cm, entire to shallowly few-lobed, glabrous to strigose, often ciliate
Inflorescence: heads obscurely radiate; lateral clusters not overtopping central; fresh involucre generally 2.5–4 mm diam; phyllaries 1–3.5 mm, glabrous to strigose, midvein resin-filled, orange when dry
Pistillate flowers 20–40; corollas 2.5–3 mm, ligule < 1 mm
Disk flowers 7–13; corollas 2.5–3 mm
Fruit ± 1.5 mm; pappus 2.5–3 mm, generally whitish in age
Chromosomes: 2n=18,36,54
Ecology: Common. Waste ground
Elevation: generally < 2000 m.
Bioregional distribution: California
Distribution outside California: ± worldwide
Flowering time: Jun–Sep

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