Milkweeds are erect, coarse growing perennials with showy white, pink, purple, or orange colored flowers. It is now naturalized in much of central and southern Europe.
Seeds are numerous, brown, flat, and thick.
By 1859, common milkweed had become a very troublesome weed in the Western U.S. and farmers found it exceedingly difficult to eradicate it especially when well established in fertile soil. Its creeping 2 to 2.6 m-long rootstock makes it a noxious weed. Although a rough coarse weed, it is not a troublesome one despite its large fleshy perennial roots and branching, leafy, hairy stems 30 to 90 cm high. From July to September it bears numerous, showy, bright orange-colored flowers, followed by long follicles with tufted silky hairs. The flowers attract butterflies, hence its common name.