Butterfly Weed

Media
Photo of butterfly weed plant with flowers
Scientific Name
Asclepias tuberosa
Family
Apocynaceae (dogbanes); formerly Asclepiadaceae (milkweeds)
Description

Butterfly weed is an herbaceous perennial, often bushy with several stems arising from the base. Flowers massively displayed in terminal umbels (umbrella-like clusters with stalks all arising from the tip of the stem). Flowers in many shades of orange to brick red, occasionally yellow. Blooms May–September. Leaves hairy, narrow, lance-shaped, dark green, on very short stems; unlike most other milkweeds, the sap of this species is not milky. Fruit 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.

Common Name Synonyms
Butterflyweed
Butterfly Milkweed
Pleurisy Root
Size

Height: to 3 feet.

Where To Find
image of Butterfly Weed Distribution Map

Statewide.

Occurs in upland fields, prairies, glades, roadsides, wasteland, dry and rocky woods, and edges of woods, often on disturbed soil.

New 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.

Another 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. Today, it is valued as a gorgeous native garden plant that is superb for attracting butterflies.

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 and 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 are on the menu for insect-eating birds.

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Similar Species

Where to See Species

Canaan Conservation Area is located in Gasconade County, near Bland. Take Route A about 1.2 miles north from Bland to the Conservation Area's southern most access road.
Scrivner Road Conservation Area is in Cole County about three miles south of Russellville. Parts of this 919-acre site were donated by Mrs. Alvon Winegar in 1984.
About Wildflowers, Grasses and Other Nonwoody Plants in Missouri
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!