Butterfly weed is an herbaceous perennial milkweed, often bushy with several stems arising from the base. The flowers can be massively displayed in terminal umbels (umbrella-like clusters with stalks all arising from the tip of the stem). The flowers may be many shades of orange to brick red, occasionally yellow. Blooms May–September. The leaves are hairy, narrow, lance-shaped, dark green, on very short stems; unlike most other milkweeds, the sap of this species is not milky. The fruits are long seedpods, to 4½ inches long, with numerous, tightly packed seeds in spirals, released and windborne on their silky floss.
Similar species: There are nearly 20 species in the genus Asclepias in our state. The flower shape of milkweeds is very distinctive. This is our only milkweed with orange flowers.
Height: to 3 feet.
Habitat and Conservation
Occurs in upland fields, prairies, glades, roadsides, wasteland, dry and rocky woods, and edges of woods, often on disturbed soil.
Native Missouri wildflower.
Evidence based on molecular (DNA) studies has persuaded botanists that the milkweeds, which used to have their own family, should be grouped within the dogbane family, the Apocynaceae. Formerly, the milkweeds were placed in their own family, the Asclepiadaceae, but now they are considered a well-defined subdivision of the dogbane family. Be aware that books and other references will differ.
Butterfly weed is valued as a gorgeous native garden plant that is superb for attracting butterflies. As more people have learned about the decline of monarch butterflies, this and other milkweeds have become extremely popular.
An antique common name, "pleurisy root," comes from this plant's historic use as a remedy for lung inflammation. There were many other medicinal uses made of this plant, which induces vomiting.
In case the name doesn't make it clear, this milkweed is a favorite nectar plant for many butterflies, and the leaves are eaten by the caterpillars of monarch butterflies.
While you’re admiring butterfly weed's orange flowers, keep an eye out for coral hairstreak butterflies. The single brood of this local and uncommon butterfly extends only from mid-June through July. The coral hairstreak has been described as being “addicted” to the blossoms of butterfly weed: “other flowers are practically ignored when this plant is present.”
Many other insects visit the flowers for nectar or chomp on the leaves, too, and their presence usually draws spiders, ambush and assassin bugs, robber flies, and other predators, forming a mini-ecosystem right on the plant. All of these invertebrates, including the predators, may be on the menu for insect-eating birds.