Annuals or perennials, eglandular; usually rhizomatous, sometimes taprooted. Stems usually not brittle at maturity, usually proximally glabrous or glabrate and distally hairy in lines, sometimes ± uniformly hairy, sometimes glabrous distally. Leaves: basal usually withering by flowering, usually petiolate, sometimes sessile or subsessile, blades 1-nerved, spatulate to oblanceolate, elliptic, or ovate to cordate, margins coarsely serrate to crenate or entire; cauline petiolate or sessile, blades widely ovate to linear, bases cordate or subcordate, rounded, cuneate, or attenuate, sometimes auriculate and ± clasping. Heads radiate or disciform. Phyllaries strongly unequal to subequal, outer sometimes ± foliaceous, green zones usually diamond-shaped to lanceolate, apices sometimes foliaceous. Ray (or pistillate) florets usually (6–) 7–50 (–60) in 1 series and laminae (3–) 5–18 (–21) × 0.8–2.8 mm, sometimes 14–110+ in 2–5+ series (sect. Conyzopsis) and laminae 4.5–5 × 0.1–0.2 mm or reduced to tubes. Disc corollas ± ampliate, throats usually ± narrowly funnelform, sometimes cylindric or funnelform-campanulate, lobes usually erect, sometimes spreading, recurved, or reflexed. Cypselae cylindric to obovoid or oblong, sometimes ± compressed, 2–6-nerved, glabrous or ± strigillose. x = 7, 8.

Distribution

North America, Mexico, Eurasia

Discussion

Species ca. 58 (51 in the flora).

Subgenus Symphyotrichum has been divided into three sections: sect. Conyzopsis (x = 7), sect. Symphyotrichum (including sect. Turbinelli) (x = 8), and sect. Occidentales (x = 8). Relationships among sections remain unresolved, and it is uncertain whether sect. Symphyotrichum, for instance, is monophyletic as defined here or elsewhere (e.g., G. L. Nesom 1994b).

Selected References

None.

Lower Taxa

Symphyotrichum sect. Conyzopsis, Symphyotrichum sect. Occidentales, Symphyotrichum sect. Symphyotrichum