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: June to September. Seed-time: July to October. Range: In southern Canada and in most parts of the United States.
Especially troublesome in the Southwest. Habitat: Fields and waste places.
A very handsome grass, but offensive to grazing animals both as green forage and as hay. Culms ten inches to three feet high, somewhat weak and flaccid, often decumbent at the lower joints, very profusely branched. Sheaths shorter than the internodes, the ligule a ring of short hairs; blades three to ten inches long, a quarter-inch to a half-inch wide, flat. Panicles three to ten inches long, with many spreading branches, densely flowered, grayish green. Spikelets ten- to forty-flowered, the florets closely imbricated, the glumes acute and keeled. Seeds reddish, very small, when ripe dropping readily from the spikelets and seeding the soil for the crop of the next year; a common impurity of timothy and other small grass seeds. (Fig. 25.)
Small areas, in yards, roadsides, and waste places, should be hoe-cut or hand-pulled while the grass is in first bloom. Hay from rankly infested meadows, though not so strong-scented as the green grass, is wiry and weedy, and of such inferior quality that it is most profitable when turned under the ground for the purpose of fertilizing a better crop.