482 COMPOSITAE (COMPOSITE FAMILY) 
golden yellow, pistillate and fertile; disks greenish yellow, hemi- 
spherical, the florets perfect and fertile; bracts of the invo- 
lucre narrow and pointed, hairy, reflexed. Aghene slenderly top- 
shaped, ribbed, and hairy, with a pappus of five to eight chaffy, 
awned scales; these achenes are too often an impurity of grass 
seeds and are a most obnoxious contamination. (Fig. 334.) 
Means of control 
Prevent seed production. Where not so abundant as to make the 
task impracticable, it pays to hand-pull this noxious plant in order 
to rid the ground of its perennial roots. Rankly infested grass- 
lands should be put under cultivation for a season. Drainage of 
the ground is discouraging to the growth of this plant, for it prefers 
the soil wet. 
PURPLE-HEADED SNEEZEWEED 
Helénium nudifiorum, Nutt. 
Native. Perennial. Propagates by seed. 
Time of bloom: June to September. 
Seed-time: August to November. 
Range: Virginia to Illinois and Missouri, southward to Florida and 
Texas. 
Habitat: Moist soil; wet meadows, sides of streams, and ditches. 
The range of this poisonous weed has been greatly widened by 
the agencies of impure commercial seeds and baled hay; it is now 
locally abundant in New England and Pennsylvania and through 
the Middle West. The plant hybridizes with its sister autumnale, 
transmitting to the progeny its own earlier habit of bloom by which 
the weed is made more obnoxious. 
Stem one to three feet tall, slender, angled, and narrowly winged 
by decurrent leaf bases, branching near the top, the younger foliage 
sparsely hairy. Leaves narrow lance-shaped to linear or the lower 
ones spatulate and toothed, the upper ones entire, sessile, and 
decurrent on the stem. Heads numerous, clustered at the ends of 
the many short branches, each about an inch and a half broad; 
disks bulging to nearly globular form, purplish brown, the florets 
perfect and fertile; rays pistillate but sterile, drooping, three- 
