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Genus :


Family :



Annual or perennial, erect herbs. Leaves alternate, crenate, serrate or pinnatifid or entire. Capitula heterogamous, numerous in terminal or axillary corymbs or panicles. Bracts 2-many seriate, linear-lanceolate, receptacle flat or concave, naked or pitted and fimbriate. Outer florets female, 2 to many seriate, tubular, filiform or shortly ligulate, fertile, inner ones hermaphrodite, yellow, tubular, 5-lobed. Anther base obtuse-entire. Style of female florets much exserted, arms filiform, that of hermaphrodite florets with flattened arms. Cypsela oblong-elliptic, pappus 1-seriate, rarely 2-seriate, hairy.

Key to the species

Serial Key Reference
1a. Stem villous; bracts margin ciliate C. semipinnatifida
1b. Stem not villous; bracts margin scarious 2
2a. Leaves elliptic-lanceolate; capitulum solitary; bracts densely pubescent C. leucantha
2b. Leaves oblanceolate; capitulum numerous; bracts not densely pubescent 3
3a. Phyllaries usually sparsely strigose; corollas of pistillate florets with laminae up to 0.3 mm wide C. floribunda
3b. Phyllaries usually glabrous; corollas of pistillate florets with laminae more than 0.3 mm wide C. canadensis