Time of bloo?n: August to October.
Seed-time: September to November.
Range: Quebec to Manitoba and the Northwest Territory, southward to Florida, Texas, and Arizona.
Habitat: Wet meadows, swamps, and along streams and ditches.
The pollen from this plant, when inhaled, causes violent sneezing and the powdered flower-heads are used in medicine for that purpose. The weed is poisonous, acrid, and pungently bitter, the flowers especially so. Horses, cattle, and sheep are sometimes killed by it; with milch cows a few mouthfuls are sufficient to taint the dairy products. Animals usually avoid the plant, but it is said that if a little is eaten an abnormal appetite is quickly formed, and then a sufficient quantity is taken to cause convulsions and death.
Stems two to five feet tall, slender, very pale green, angled and winged, branching at the top. Leaves alternate, firm, oblong to elliptic, rather coarsely toothed, pointed at both ends, sessile and decurrent on the stems, forming narrow wings. Heads numerous, often nearly two inches broad, borne at the ends of many short branches at the top of the stem; rays drooping, wedge-shaped, three-toothed at the tip, bright
Fig. 334. - Sneezeweed (Helenium autumnale). X 1/4.
2I golden yellow, pistillate and fertile; disks greenish yellow, hemispherical, the florets perfect and fertile; bracts of the involucre 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.)
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 grasslands 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.