248 KEY AND FLORA 
few shorter ones at the base; receptacle naked or pitted. Ray 
flowers yellow or orange, pistillate and fertile when present; 
disk flowers tubular, bisexual. Akenes cylindrical or com- 
pressed, not beaked or winged, 5-10-ribbed, downy; pappus 
of numerous slender white hairs.* 
1. S. glabellus Poir. Burrerweep. Annual; stem erect, ridged, 
hollow, often woolly when young and becoming smooth with age, 
branched above, 1-3 ft. high. Leaves lyrate-pinnatifid, thin, the lower 
petioled, the upper sessile. Heads radiate in a terminal corymb; bracts 
linear, acute. Ray flowers about 12, yellow. Akenes slightly rough- 
hairy on the angles; pappus rough, longer than the involucre. Com- 
mon on low ground.* 
2. S. aureus L. GorpEN RaGweep. Perennial; stems often 
tufted, erect, slender, woolly when young, branched above, 18-30 in. 
high. Lower leaves broadly ovate, obtuse at the apex, heart-shaped 
at the base, crenate, long-petioled; stem leaves lanceolate and often 
pinnatifid, the upper small and sessile. Heads radiate, corymbed, on 
slender peduncles. Ray flowers 8-12, bright yellow. Akenes smooth. 
In wet soil; very variable.* 
3. S. tomentosus Michx. Wootty Racweep. Perennial; woolly 
throughout; stem stout, erect, mostly simple, 2-3 ft. high. Lower 
leaves ovate to oblong, crenate or entire, obtuse, long-petioled; stem 
leaves few, elliptical to oblanceolate, serrate or toothed, acute, sessile. 
Heads radiate, 3 in. wide, on slender peduncles; bracts narrow, be- 
coming smooth. Ray flowers 12-15, yellow. Akenes hairy. In damp 
soil.* 
XII. CIRSIUM Hill. (CARDUUS) 
Biennial or perennial; stem erect, simple or branched. 
Leaves alternate, prickly, often forming wings on the stem. 
Heads discoid, terminal and solitary or corymbed, many-flow- 
ered; bracts overlapping in many series, the outer shorter, 
usually spine-pointed ; receptacle bristly. Corollas purplish 
or nearly white, the tube slender, deeply 5-cleft. Akenes 
oblong, 4-angled, smooth or ribbed; pappus of numerous 
simple or plumose bristles. [Most of our commoner species 
blossom in the late summer and autumn. ]* 
1. C. spinosissimum Scop. Yettow TuistLe. Biennial or perennial ; 
stem erect, stout, woolly when young, becoming smooth, often purple, 
branched, 1-3 ft. high. Leaves pinnately cut, with very spiny teeth, 
mostly sessile and clasping, smooth and green on both sides. Heads 
