yt FOUNDATIONS OF BOTANY 
large and showy, with a yellow disk and many white rays. A trouble- 
some but handsome perennial weed. Introduced from Europe, 
chiefly E. 
2. C. frutescens, L. MarcGuerite. Erect, branching, perennial, 
woody below, smooth, and with a pale bloom. Divisions of the 
leaves linear, with the uppermost leaves often merely 3-cleft bracts. 
Heads long-peduncled, showy, with a yellow disk and large, spread- 
ing white rays. Cultivated in greenhouses; from the Canary Islands. 
IX. SENECIO, Tourn. 
Annual or perennial; stems often hollow. Leaves alternate, 
entire or pinnately divided. Heads with or without rays, in 
terminal corymbs; bracts mostly in a single row, often witha 
few shorter ones at the base; receptacle naked or pitted. Ray- 
flowers yellow or orange, pistillate and fertile when present ; 
disk-flowers tubular, perfect. Akenes cylindrical or com- 
pressed, not beaked or winged, 5-10-ribbed, downy. Pappus 
of numerous, slender, white hairs.* 
1. S. tomentosus, Michx. WooLty RAGWEED. 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, 
becoming smooth. Ray-flowers 12-15, yellow. Akenes hairy. On 
damp soil.* 
2. S. aureus, L. GoLpEN RAGWEED. Perennial; stems often 
tufted, erect, slender, woolly when young, branched above, 18-80 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. On wet soil; very variable.* 
3. S. lobatus, Pers. BurrERWEED. 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. Common on low ground.* 
