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 July. Seed-time: July to August. Range: Manitoba, Minnesota, and the Dakotas. Habitat: Grain fields, meadows, railway embankments, roadsides, and waste places.
A native of Siberia, first appearing in this country in 1886, in Canada near Winnipeg, Manitoba; since when the plant has spread very rapidly, east, west, and south. It is a coarse, deeply rooted, grossly feeding weed, two to four feet in height, widely branched and very leafy, seriously crowding the crops among which it grows. When young, it somewhat resembles Lamb's Quarters, but, instead of being mealy, the branches and under side of the leaves are clothed with very short, star-shaped hairs. (Fig. 73.)
Stem rather stout, grooved, light-colored, very hard and woody when mature, and injurious to harvesting machines. Leaves alternate, lance-shaped, with short petioles, sparsely toothed or wavy-edged, the upper ones entire. Flowers of two kinds, at first green and inconspicuous, the staminate ones in slender spikes, terminating the many branchlets; the fertile flowers below, thickly clustered in the axils; these each produce a single ovoid, flattened seed, about a tenth of an inch long, minutely ridged lengthwise, gray and shining; many seeds have the utricle or papery covering persistently enfolding them and projecting from the top as a two-lobed wing. When mature, the stems, bracts, and calyx lobes turn white, and the plants are then very conspicuous. They frequently become tumble-weeds, the woody, brittle stems breaking at the base and the whole weed rolling away before the wind, sowing seed as it goes; by this means its range is being very rapidly extended.
In grain fields, large numbers of the young seedlings may be dragged out with a weeding harrow, in the spring, when the crop is but a few inches high; plants that survive this treatment should be hand-pulled later, but before their rank growth injures the crop by absorbing its food and moisture. Meadows infested by the weed should be early cut in order to prevent fouling the soil with the seed. Plants along roadsides and railways and in waste places should be cut while in early flower, and burned so as to make certain that no seed shall mature.