This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Perennial. Propagates by seeds and by taking root at the lower joints. Time of bloom: June to August. Seed-time: July to September. Range: Newfoundland to British
Columbia, southward throughout the United States; also in Europe and Asia. Habitat: Moist meadows, banks of streams, and ditches; often troublesome in damp cultivated ground.
A slender, low-growing grass, with the habit of forming "knees" and rooting at the lower joints; it is said to be nutritious grazing when young and tender, but yields a very small amount of hay to the acre, and the hay is of poor, harsh quality.
Culms eight to eighteen inches tall, smooth, simple or sparingly branched, erect above the decumbent base. Sheaths shorter than the internodes, the upper one usually inflated; leaves rough, two to six inches long and hardly an eighth of an inch wide. Spikes dense, cylindrical, one to three inches long and about a third of an inch in diameter; spikelets one-flowered, flattened, the glumes equal, united at base, obtuse, with hairy keels; the lemma much shorter, obtuse, and smooth, the awn attached slightly below the middle and bent, the portion exserted being usually twice as long as the glumes. (Fig. 19.)
Fig. 19. -Marsh Foxtail (Alopecurus geniculatus). X 1/4.
Drain the ground and follow with a season of intensive cultivation and fertilization before reseeding heavily to better and much more profitable grasses, such as red-top and timothy.