St Charles County Master Gardeners

Common Milkweed

 

 

Asclepias syriaca

Family:  Asclepiadaceae (milkweeds)

Description: 

A sturdy, upright plant with broad leaves, milky sap, and clusters of pink or lilac flowers. Blooms May through August. Flowers are pink to lilac, very fragrant, borne in clusters terminally and along the stems, arising from leaf axils. Leaves are broadly elliptical, rounded at the base, to 6 inches long, with find hairs underneath, on distinct leaf stalks. Fruit are large seedpods (follicles), elongated and covered with slender warty projections. When dry, these split to release hundreds of seeds, each attached to a “parachute” of white, silky, flossy hairs that can carry them on the wind.

Similar species: There are 17 species in the genus Asclepias in Missouri. The one most similar is purple milkweed, whose flowers are darker and more purplish and whose pods lack slender warty projections.

Size: Height: usually to about 3–4 feet, but can grow to 6 feet.

Habitat and conservation: 

Grows on upland fields, prairies, pastures, glades, roadsides, wasteland, edges of woods, and open, disturbed places. This is the most commonly seen milkweed, especially in abandoned fields and waste places, where it is an early colonizer of disturbed soil.

Distribution in Missouri: 

Statewide.

Status: Common.

Human connections: 

This plant has many uses. There have been attempts to make rubber out of the sap’s latex. The flossy seed hairs have been used as a stuffing. The dried pods are used in crafts and flower arrangements. The stem fibers can be used as a source for cordage, similar to flax or hemp.

Ecosystem connections: 

 

This is an important food plant for monarch butterflies, whose caterpillars munch the foliage, storing in their bodies milkweed’s toxic sap. This makes the monarch unpalatable to would-be predators. Other, less-celebrated insects eat milkweed and defend against predation the same way.

Common Milkweed

 

A wildflower common statewide, found in a variety of habitats, common milkweed is famous as a food plant for monarch butterflies. It is also notable for its curious seedpods bearing seeds that fly on silky parachutes.