Flora of North America species comparison

usually erect, ± branched, spiny-winged.

basal and cauline; winged-petiolate (basal) or sessile (cauline);

blade bases narrowing, margins pinnately lobed or divided and dentate, teeth and lobes tipped with stout spines.

hemispheric to ovoid or spheric.

flat to convex, epaleate, not bristly, alveolate with apically fringed pits.

many;

corollas white or purple, actinomorphic or weakly zygmorphic, tubes slender, throats cylindric or narrowly goblet-shaped, lobes linear;

anther bases acute-tailed, apical appendages subulate;

style branches: fused portions with minutely hairy nodes, long, cylindric, minutely papillate, distinct portions minute.

many in 8–10+ series, linear to ovate, entire, tapered to stiff spines, middle and outer often spreading or reflexed.

discoid, borne singly or in corymbiform arrays; (peduncles 0 or spiny winged).

± cylindric, 4–5-angled, usually ± transversely roughened, glabrous, attachment scars basal;

pappi falling in ring, of many barbed or plumose bristles, basally connate.

= 17.