(Vernonia gigantea, Britton)
(Vernonia maxima, Small)
Range: New York to Michigan and Illinois, southward to Missouri, Louisiana, and Alabama. Habitat: Prairies; meadows, pastures, and roadsides.
This great weed is the despair of the prairie farmer, who sees it take possession of his rich soil, appropriating most of the food and moisture and crowding out the grasses; the plant is rejected by all grazing animals, even sheep.
Stem four to ten feet tall, erect, strong and woody, branching near the top, springing from roots like thick, fibrous cords, forming a huge tassel at the base of the stalk and penetrating in all directions. Leaves alternate, narrow lance-shaped, thin, dark green, pointed at both ends, finely toothed, sessile, usually smooth on both sides. Heads in large, rather loose, terminal cymose clusters, deep reddish purple; florets all perfect and fertile with tubular, five-lobed corollas; stamens five, united in a tube about the cleft-tipped style, a characteristic of all composites; involucre top-shaped, purple-tinged, its bracts imbricated in several series, closely appressed. Achenes bristly ribbed, with a double pappus, the outer row of short, very stiff, scalelike bristles, the inner row much longer, of many fine, rough hairs. (Fig. 288.)
In cultivated crops the perennial roots are destroyed by the plow and the following tillage, but in land where there is danger of washing, or which for other reasons is not desired to be put under cultivation, the grubbing-hoe or the scythe must be persistently used. Cut closely in May, repeating in June, and again in August and September, thus preventing all seed development and exhausting the roots of all sustenance supplied by the leaf-growth.