Climbing Milkweed

Matelea decipiens

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Photo of climbing milkweed flowers and leaves.
The brown, starlike, spreading flowers of climbing milkweed differ from those of other milkweeds.
Mark Sullivan
Family

Apocynaceae (dogbanes); formerly Asclepiadaceae (milkweeds)

Description

A climbing or trailing perennial vine with milky sap. Flowers brownish purple, like a 5-pointed star, with spreading corolla lobes ½–¾ inch long; the flower clusters arise on stalks from the leaf axils. Blooms May–June. Leaves opposite, broadly ovate and heart-shaped, to 6 inches long. Fruit a narrow pod, to 4 inches long, covered with slender, warty projections.

Similar species: Another climbing milkweed, M. baldwyniana, with whitish corolla lobes, is scattered in southwestern Missouri. Angle-pod (Gonolobus suberosus), found mostly in the Bootheel, resembles Mateliea species vegetatively but has yellowish flowers and angled (ridged) pods without warty projections. Sand vine and black swallowwort (Cynanchum spp.) have clear, not milky sap, and tiny flowers with upright, not spreading corolla lobes.

Size

Stem length: to nearly 10 feet.

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small purple flowers rise from broad green milkweed leaves
Climbing milkweed at Shaw Nature Reserve
Habitat and conservation

Occurs in glades, savannas, tops of bluffs, rocky, open upland forests, and along streams and rivers. Less common in bottomland forests. Also found along roadsides.

image of Climbing Milkweed distribution map
Distribution in Missouri

Scattered to common, mostly south of the Missouri River.

Status

The entire former milkweed family (Asclepiadaceae) has recently been rolled into the dogbane family (Apocynaceae). For many years, botanists have known the two families were closely related. The milkweed group, with its distinct floral structures, is still considered a unique subfamily or tribe of the dogbane family. As you consult various sources, you can expect to see milkweeds grouped in either family.

Human connections

This native vine can be trained on a trellis or fence, where it will attract butterflies. In Illinois and Maryland, the species is listed as endangered; in Maryland, it is probably extirpated. Loss of habitat is probably the cause.

Ecosystem connections

Butterflies and other insects are attracted to the flowers. A vining habit enables a plant to use another plant or structure as a support, so it can reach higher, towards the sun and pollinators, without expending resources to develop a stout stem or trunk.