Flora of North America species comparison

simple or often branched from base, forming rounded bushy plants, gray-tomentose.

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

gray-tomentose and scabrous to short-bristly;

basal and proximal cauline petiolate or tapered to base, usually absent at anthesis, blades 5–15 cm, margins pinnately lobed or dissected;

cauline long-decurrent, blades linear to oblong, 1–10 cm, entire.

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.

ovoid, 13–17 mm, loosely cobwebby-tomentose or becoming glabrous.

± spheric, 20–40 mm.

many;

corollas yellow, all ± equal, 13–20 mm;

sterile florets slender, inconspicuous.

many;

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

appendages scarious, obtuse or abruptly spine tipped.

disciform, borne singly or in open leafy arrays, long-pedunculate.

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

dimorphic, 2–3 mm, glabrous, outer dark brown, without pappi, inner white or light brown, mottled;

pappi of many white, unequal bristles 2–4 mm, fine.

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.

phyllaries: bodies pale green, ovate, appendages stramineous to brown, each with palmately radiating cluster of spines, and stout central spine 10–25 mm.

= 16.

= 22.