440 COMPOSITAE (COMPOSITE FAMILY) 
sion to go where mosquitoes are troublesome; it is also used in 
medicine, and the dried plants are quoted at five to six cents a 
pound in the drug market; its juices are resinous and bitter, 
and grazing animals will not touch the weed. The hands should 
be protected when pulling or collecting the plants, for the oily 
and acrid juices are sometimes very irritating to the skin, pro- 
ducing an eruption which resembles that caused by the touch of 
Poison Ivy. 
In good soil the stem may attain to a height of ten feet, and, 
again, it will adapt itself to hard conditions and bloom when less 
than six inches tall; it is erect, finely 
grooved, bristly with short hairs, simple or 
branching from the base; when cut it stools 
freely, hastening to develop new fruiting 
branches. Lower leaves spatulate or some- 
times cut-lobed, tapering to petioles; upper 
ones usually entire, lance-shaped to linear, 
finely hairy, much crowded on the stalks. 
Heads in panicled clusters, very small and 
very numerous, each about a sixth of an 
inch broad, with smooth, cylindric invo- 
lucre, nearly concealing the very small, 
white rays. Seeds many and small, with 
yellowish brown pappus. (Fig. 305.) 
Means of control 
Where not too abundant to make the task 
impracticable, hand-pull the weeds and re- 
move them from the ground, for the woody 
stalks contain enough nutriment to mature 
the first-opened flowers. Burn over stubbles 
on infested grain fields for the purpose of 
Fie. 305.— Canada 
Fleabane (Erigeron S 
ee, vee destroying the seeds on the ground. Mead- 
ows badly “run to Horseweed” should be 
put to a well-tilled hoed crop before reseeding. Plants of roadside 
and waste places should be pulled or cut in early bloom or before, 
for the protection of adjacent property. 
