in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 271. 1838.
Perennials [subshrubs] (dioecious or subdioecious), 20–80 (–120+) cm; fibrous-rooted (rhizomatous, not stoloniferous). Stems usually 1, usually erect. Leaves basal and cauline; alternate; petiolate or sessile; blades oblanceolate or lanceolate to linear, bases ± cuneate, margins entire, faces usually bicolor [concolor], abaxial usually white to gray and tomentose (sometimes glandular as well, proximal leaves sometimes ± glabrate), adaxial usually greenish and glabrate or glabrous, sometimes grayish and sparsely arachnose. Heads usually discoid (unisexual or nearly so) or disciform, in glomerules in corymbiform or paniculiform arrays. Involucres subglobose, 6–8 (–10) mm. Phyllaries in 8–12 series, bright white (opaque, at least toward tips, often proximally woolly; stereomes not glandular), unequal, ± papery (at least toward tips). Peripheral (pistillate) florets 50–150 (more numerous than staminate; sometimes a few pistillate florets peripheral in predominantly staminate heads or 1–9 staminate florets central in predominantly pistillate heads); corollas yellowish. Inner (functionally staminate) florets 30–55; corollas yellowish. Cypselae oblong [obclavate, ovoid, or cylindric] (2-nerved), faces ± scabrous (hairs clavate, not myxogenic); pappi usually readily falling, of 10–20 distinct or basally connate, barbellate bristles (tips of bristles ± clavate in bisexual or functionally staminate florets). x = 14.
North America, mostly central Asia and India
Species ca. 110 or fewer (1 in the flora).