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.
Dioecious or polygamo-dioecious, the pistillate heads sometimes with a few central staminate fls; heads disciform or discoid; invol bracts imbricate, almost wholly dry and scarious; receptacle naked, flat or convex; pistillate fls with tubular-filiform cor and bifid style; staminate fls with coarser, tubular cor and generally undivided style; anthers caudate; pappus of distinct capillary bristles, neither clavellate nor conspicuously barbellate; white-woolly perennials with alternate entire lvs. 25+, N. Temp., mostly e. Asia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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