Butterfly weed (Asclepias tuberosa), also known as butterfly milkweed, pleurisy root and orange milkweed, is a flowering herbaceous perennial that grows on hillsides and in open woodlands in eastern North America. It works well in natural areas and mixed borders.
Butterfly weed plants grow between 1.5 and 2 feet tall. They have large taproots that produce single or multiple stems. Their shiny dark green leaves are lance-shaped with pointed tips. Flat-topped clusters of orange blossoms emerge between May and September, followed by small green pods that release wind-borne seeds.
Monarch butterfly (Danaus plexippus) caterpillars feed exclusively upon butterfly weed foliage. Butterfly weeds are larval hosts for queen (Danause gilippus) and grey hairstreak (Strymon melinus) butterflies, and provide nectar for many other butterfly species and for hummingbirds.
Butterfly milkweed grows in U.S. Department of Agriculture plant hardiness zones 4 through 10. It prefers full sunlight or partial shade and sandy, well-drained soil. Butterfly milkweed plants are drought-tolerant. The Illinois Wildflowers Info website indicates that plant-eating mammals often avoid this plant because of its bitter taste.