This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Annual. Propagates by seeds.
Time of bloom: July to September.
Seed-time: August to October.
Range: All cultivated regions of the world.
Habitat: Moist, rich soil; gardens, fields, and waste places.
The Indians of Arizona and Southern California use the seed of this grass for food; cattle are very fond of it when green and succulent; and in some parts of the country, particularly in the flooded river-bottom lands of the Southwest, it yields heavy volunteer crops of hay. But generally it is considered a weed. Its seed is nearly always found with that of other grasses and of clover. (Fig. 8.)
Culms stout, smooth, two to five feet tall. Sheaths compressed, smooth; blades six inches to nearly two feet long, a half-inch to an inch wide, smooth, with a strong central nerve and margins somewhat rough. Panicle large, four inches to a foot or more long, variable, composed of numerous sessile branches, erect or spreading, or the lower ones reflexed. Spikelets one-seeded, nearly sessile, ovate, in three or four irregular, densely crowded rows on one side of the rachis, varying in color from deep purple to pale green, sometimes long-awned, but often without awns, the glumes unequal, sharp-pointed, and bristly-hairy. Seeds about an eighth of an inch long, pointed ovoid, plump.
Cutting so frequently that no seed can mature. In cultivated ground the weed is easily kept in subjection by hoe-cutting while small.
 
Continue to: