142. Eurybia (Cassini) Cassini in F. Cuvier, Dict. Sci. Nat. 16: 46. 1820.
北美紫菀属 bei mei zi wan shu
Authors: Yilin Chen & Luc Brouillet
Aster subg. Eurybia Cassini, Bull. Sci. Soc. Philom. Paris 1818: 166. 1818.
Perennials, rhizomatous, usually eglandular [sometimes stipitate glandular]. Stems ascending to erect, usually simple, rarely branched at base, glabrous or ± densely hairy. Leaves basal and cauline, sessile or petiolate, blade cordate, ovate, obovate, elliptic, or oblong to spatulate, oblanceolate, or lanceolate, glabrate to hairy, margin entire or serrate [sometimes spinulose-serrate]. Capitula radiate, numerous, usually in corymbiform synflorescences, rarely solitary. Involucre cylindric-campanulate to broadly campanulate; phyllaries in 3-7 series, unequal, bases hardened (rarely wholly leaflike), glabrous or ± hairy [sometimes ± stipitate glandular], margins narrowly scarious (seldom herbaceous), green zones ± basally truncate, in distal 1/3-3/4 (outer) or less (inner), 1-veined, apices obtuse to acute. Receptacles flat to slightly convex, alveolate, epaleate. Florets fertile. Ray florets few to many, purple [or white]; disk florets few to many, bisexual, yellow, limb funnelform to campanulate, lobes 5, deltate to lanceolate; anther base obtuse, apical appendage lanceolate; style branch tip lanceolate. Achenes cylindric-obconic to fusiform, ± compressed, glabrous or sparsely to densely strigillose, eglandular, 7-12(-18)-veined. Pappus persistent, reddish to yellowish, in 4 series, of numerous unequal, barbellate bristles, inner apically ± clavate.
Twenty-three species: Asia, Europe, North America; one species in China.
Eurybia is North American. Eurybia sibirica extended into N Eurasia via the Bering land bridge.