Time of bloom: June to August.
Seed-time: August to October.
The horizontal creeping rootstock which makes this plant such a noxious weed is often six or eight feet long, wrinkled, cylindrical, white inside, with a grayish brown bark, warty with the scars of former stems. It is medicinally valuable, and, when collected in autumn, cleaned, transversely sliced and dried, is worth six to eight cents a pound in the drug market. Grazing cattle dislike the bitter, milky juice and the weed is a pest in pastures. When young, the crisp, succulent shoots make an excellent "dish of greens," cooked like asparagus. (Fig. 221.)
Stem stout, two to five feet tall, softly downy when young but growing smooth with age, erect, and usually simple. Leaves arranged in opposing pairs on alternate sides of the stalk, oblong to elliptic, smooth above, finely downy below, entire, the nerves extending from the strong midrib uniting themselves by a bordering thread before reaching the margin; petioles stout, very short. Umbels terminal and lateral, dense, the flowers dull purple to pinkish, fragrant. Follicles three or four inches long, downy, and covered with soft, spinous projections. Seeds very many, brown, flat, their tufts of fine silken hair long and thick. Should they fall on water, Milkweed seeds can float, as well as fly, for each has a corky margin which makes of it a raft.
Cutting and many times cutting, throughout the growing season, depriving the rootstocks of all sustenance if possible. Plants should not be allowed to form fruit before cutting, for the pods ripen on the stalks.
Fig. 221. - Common Milkweed (Asclepias syriaca). X 1/4.