Native. Biennial or winter annual. Propagates by seeds. Time of bloom. June to August. Seed-time: July to September. Range: Labrador to Alaska, southward as far as Maryland, Kansas, and California. Most troublesome in the West. Habitat: Fields, meadows, pastures, and waste places.
Because of its beauty this plant is sometimes used for ornamental purposes; but it never should be, lest it spread to do injury where it is not wanted. The long, barbed, reddish-golden awns become very brittle when ripe, and break into small bits which work between the teeth and into the jaws of animals that eat the grass, causing such ulcerations and swellings as sometimes to be mistaken for the disease called "Big Jaw" or "Lumpy Jaw" (Actinomycosis); they get into the nostrils and into the eyes, sometimes causing blindness; they also work into the tissues of the throat and the alimentary canal, setting up an irritation which may end in ulceration and death. The injury to horses, cattle, and sheep from this cause is great, particularly in the West. (Fig. 32.)
The grass grows in thick tufts from fibrous and clustered roots. Culms ten to thirty inches tall, smooth, erect or sometimes decumbent at the lower joints. Sheaths shorter than the internodes; blades two to five inches long, flat, rough, and grayish green; spikes nodding, three to five inches long, the spreading awns making them nearly as broad; spikelets in threes, on opposite sides of the flattened jointed rachis; only the central one produces a seed, the lateral flowers being sterile; glumes equal, rigid, narrow and bristle-pointed, placed at the side of the compressed spikelet which is placed with its back against the spike; the lemma of the fertile flower is armed with a long, sharply barbed awn, and the sterile flowers have three apiece, so that each spikelet has seven awns, all barbed. These rough-awned seeds cling to the hair and the wool of animals, and are carried by the wind, and by the water of irrigating ditches, along which the pest loves to grow - although it adapts itself to almost any soil, even the dry, alkaline regions where few other grasses thrive.
Mowing the grass so early and so frequently as to prevent the formation of the barbed seed-heads. If the infestation is new and the plants are not too numerous, hand-pull and destroy them. Large areas may be burned over, killing the plants and any seeds on the surface. Cultivation of the ground will exterminate the weed, care being taken to leave no stragglers along fence rows and ditches.