This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds.
Time of bloom: August to September.
Seed-time: September to October.
Range: Michigan to the Saskatchewan, and southward to Illinois, Colorado, and Texas. Habitat: Meadows, waste places, borders of streams.
Stems rough, stout, woody, three to eight feet in height, simple or with a few branches at the top. Leaves three to six inches long, lance-shaped, pointed at both ends, thick and leathery, rigid, rough on both sides, with sharp but shallow teeth or sometimes entire, and are mostly sessile, only the lowermost ones narrowing to a short, rigid petiole. Heads few, usually solitary at the ends of stem and branches, two to four inches broad, with twenty to twenty-five light yellow sterile rays; the fertile disk-florets are purplish brown. Achenes oblong, hairy, crowned with two broad scales and often with several small, sharp-pointed awns.
Most readily suppressed by cultivation of the soil, which destroys the perennial roots; or by frequent and close cutting during the growing season, which starves the roots and prevents seed development.
 
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