General: Milkweed Family (Asclepiadaceae). Asclepias tuberosa is a perennial herb 3-9 dm tall with woody rootstocks. According to Kelly Kindscher (1992), "Asclepias comes from the name of the Greek god of medicine, Asklepios. The species name, tuberosa, means full of swellings or knobs, referring to the enlarged root system." Butterfly milkweed stems are hairy, erect, and grow in numerous clumps. There is a watery sap within the stems and leaves. The leaves are alternate, simple, crowded, lance-shaped, 5-10 cm long, shiny green, smooth above and velvety beneath. The flowers are in showy, rounded to flat-topped groups near the ends of branches. Each flower has 5 petals, bent downward, orange to red or sometimes yellow, topped by a crown of 5 erect hoods, each one containing a short horn. Fruits are hairy, spindle-shaped pods 8-15 cm long. The numerous seeds each have a tuft of long white hairs at the tip.