450 COMPOSITAE (COMPOSITE FAMILY) 
while on each side of it springs 
a stalk, taller than itself, bear- 
ing a leaf-cup, which in turn 
will have a central head and 
two more cup-bearing stalks; 
these will fork again, and yet 
again, the series being some- 
times “four stories high,” as 
an observant child remarked. 
Each head resembles a small 
sunflower, two or three inches 
broad, with twenty to thirty 
narrow, yellow rays, pistillate 
and fertile; the ‘disk-florets 
are sterile; involucral bracts 
in triple rows,. broadly ovate, 
and conspicuous. Achenes en- 
circle the outer edge of the 
head, as only the rays form 
fruit; they are oval, broad, 
brown, flat, notched at apex, 
winged on each side, with a 
pappus of two awn-like teeth. 
The same methods of exter- 
mination should be used as for the Compass Plant. (Fig. 313.) 
Fic. 313. — Cup Plant (Silphium per- 
foliatum). X 4. 
ROUGH MARSH ELDER 
Tva ciliata, Willd. 
Native. Annual. Propagates by seed. 
Time of bloom: August to October. 
Seed-time: September to November. 
Range: Illinois to Nebraska; and southward to Louisiana, Texas, 
and New Mexico. 
Habitat: Meadows and fields, sides of streams, and waste places. 
A coarse, unsightly weed, bristly with rough hairs, two to seven 
feet in height, the erect stem usually simple but sometimes branched 
and often mottled with different shades of green. Leaves opposite, 
