28. Carduus L. (plumeless thistle)

Plants coarse, biennial or less commonly annual, with stout taproots. Stems erect, usually branched, noticeably spiny-winged, glabrous or finely hairy, sometimes felty-hairy toward the tip. Leaves basal and alternate, sessile, the bases decurrent into wings along the stem, these wavy or scalloped to evenly lobed, spiny along the margins. Basal leaves in a dense, overwintering rosette, the blades large, broadly elliptic to lanceolate or oblanceolate, deeply pinnately lobed, the lobes somewhat irregular and also toothed to lobed, the margins spiny, the surfaces glabrous or hairy. Stem leaves shallowly to deeply pinnately lobed, occasionally nearly entire, elliptic to lanceolate or narrowly oblong-elliptic or the margins spiny, the surfaces glabrous or hairy. Inflorescences axillary and terminal, the heads long-stalked to nearly sessile, solitary or in small clusters at the branch tips. Heads discoid, the involucre cup-shaped to somewhat bell-shaped, the florets all appearing similar and perfect. Receptacle flat or slightly convex, with numerous bristles. Involucral bracts (except sometimes the innermost ones) tapered to a spiny tip. Pappus of numerous long capillary bristles, these fused at the base, roughened with minute, ascending barbs or teeth, shed more or less as a unit before fruiting. Corollas reddish purple to purple, rarely white. Fruits appearing basally attached, 2.5–4.0 mm long, oblong or slightly narrower at the symmetrical base, somewhat flattened and sometimes slightly 4-angled in cross-section, the tip usually with a slightly raised rim, the surface somewhat shiny, light brown to grayish brown, with numerous longitudinal, darker brown stripes. About 90 species, Europe, Asia, Africa.