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. Achene 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 



Helenium nudiflorum, 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- 



