Flora of North America species comparison

often spreading or prostrate, usually branched throughout, usually reddish, ± loosely tomentose.

usually 1, erect, ± openly branched distally, loosely tomentose.

mostly cauline, sessile and often short-decurrent or proximal tapering to winged petioles, blades lanceolate to oblanceolate, 6–25 cm, margins coarsely dentate or pinnately lobed, lobes and teeth armed with short, weak spines, faces sparsely to densely hairy with jointed multicellular hairs and slender cobwebby hairs, resin-gland-dotted.

± loosely gray-tomentose;

basal leaf blades linear-lanceolate, 3–10 cm, margins entire or with remote linear lobes, apices acute;

cauline linear, usually not much smaller except among heads, usually entire.

± spheric, 20–40 mm.

campanulate, 12–16 mm.

many;

corollas yellow, those of sterile florets linear, 3-lobed, not exceeding disc corollas, very slender, those of disc florets 19–24 mm.

25–35;

corollas blue (white to purple), those of sterile florets raylike, enlarged, 20–25 mm, those of fertile florets 10–15 mm.

in several series, tightly overlapping, outer ovate with tightly appressed bases and spreading spine tips, inner lanceolate, tipped by pinnately divided spines more than 5 mm.

bodies green, ovate (outer) to oblong (inner), tomentose or becoming glabrous, margins and erect appendages white to dark brown or black, scarious, fringed with slender teeth ± 1 mm.

disciform, borne singly, sessile, each subtended by involucre-like cluster of leaf-like bracts.

radiant, in open, rounded or ± flat-topped cymiform arrays, pedunculate.

cylindric, slightly curved, 8–11 mm, with 20 prominent ribs, tipped by a 10-dentate rim, glabrous, attachment scars lateral;

pappi of 2 series of awns, outer 9–10 mm, smooth or ± roughened, inner 2–5 mm, roughened with short spreading hairs.

stramineous or pale blue, 4–5 mm, finely hairy;

pappi of many unequal stiff bristles, 2–4 mm.

= 22.

= 24 (Russia).