Swamp Milkweed and Butterfly Milkweed

A Tale of Two Milkweeds

One has orange flowers, one has pink. One likes moist soil; the other doesn’t mind dry. One blooms in fall, the other in summer.

Both are striking plants, a bit otherworldly.  With their waxy flowers, poisonous milky sap, and seed pods filled with silky seeds, that blow in the wind like tiny balloons, they would look at home in a Star Trek episode.

That said, they are native plants, at home in Oklahoma, two of 26 milkweed species native to the state.  And they are essential plants in our ecosystems, providing food for bees, wasps, flies, and butterflies such a swallowtails and fritillaries, even hummingbirds.

Monarch butterflies love them both– they eat them, lay their eggs on them and drink the nectar in their flowers. In fact, without these and other milkweeds, monarchs will die

At the Kerr Center we have planted both swamp milkweed (Asclepias incarnata) and butterfly milkweed (Asclepias tuberosa). We have planted both in the Kerr Center office landscape.

David Redhage, pollinator project director, captured these images of monarchs caterpillars eating the swamp milkweed. At the same time, he noticed that the butterfly weed was left untouched. Notes Patricia Folley in her The Guide to Oklahoma Wildflowers, “It is our only milkweed without a milky sap, which may explain why, though its nectar attracts many butterflies, they do not prefer it for laying their eggs.”