This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Annual. Propagates by seeds. Time of bloom: July to September.
Fig. 325. - Prairie Cone-flower (Lepachys columnaris).
2h Seed-time: August to October.
Range: Minnesota to the Northwest Territory, and southward to Missouri and Texas. Locally in the Eastern States. Habitat: Meadows, waste places, fence rows, roadsides.
When kept within bounds this is a useful plant, which for many years has been extensively cultivated both in this country and in Europe. A fine, clear oil is expressed from its seeds, which are also a very nutritious and fattening food for poultry, horses, and other stock. Its leaves also are considered good fodder.
In rich soil some of the cultivated forms attain to fifteen feet in height, with flower-heads a foot or more across. But in its native home on the western prairies the stout, rough stem is usually three to eight feet tall, branching at the top. Leaves three inches to a foot in length, broadly oval, pointed, three-ribbed, rough on both sides, with stout, hairy petioles. Heads three to six inches broad, with many large, bright yellow, sterile rays; disk-florets tubular, five-lobed, dark purple or brown, perfect, and fertile. Involucre depressed with oblong, rough-hairy, and sharp-pointed bracts. Achenes large, oblong, nearly smooth, grayish brown with white marginal stripes, with a deciduous pappus of two to four thin chaffy scales.
The weed is readily subdued by cultivation of the soil; but in meadows and other ground where tillage is not practicable, seed development should be prevented by cutting or pulling the plants while in their first bloom. Plants growing along roadsides, banks of streams, and waste places should have like treatment.