Milkweed Plant Facts

Reader tips to live by.

By Reader Tips
Updated on July 22, 2026
article image
by Leah Smith
Milkweeds support monarchs and other lepidopterans as well as bees, flies, and hummingbirds.

Asclepias is the genus of the milkweeds, plants that possess an interesting history. Their scientific name comes from their reputation as a medicinal herb, and the genus references the Greek god of medicine and healing, Asclepius (Asklepios). Once used to treat everything from bee stings, warts, and ringworm to fever, dysentery, and asthma, these days, because of the toxic cardiac glycosides Asclepias species contain, they should be used only with extreme caution – or not at all.

Milkweed Plant Facts

The common name “milkweed” refers to the milky-white, sticky latex that exudes from wounds to these plants, and that latex contains the cardiac glycosides. This combination physical-and-chemical defense system helps protect them from herbivorous pests, though not completely; mammals will eat them, especially young plants, when other food is scarce, and though most insects will steer clear, there are exceptions.

Milkweeds are some of the most diverse and widely distributed native wildflowers in North America. There are over 100 species, displaying flat-to-globe-shaped umbel flower heads in a variety of colors, including pink, purple, white, green, and orange. Some species love full sun, while others prefer partial shade. Some like to grow in wet ground, while others want dry land. With a species for every situation, you’re just as likely to find a milkweed in the desert Southwest as in the Florida Everglades.

Probably the most recognized member of the genus is A. syriaca, the common milkweed. It’s best known as the host plant of the monarch butterfly, which itself enjoys iconic status, in no small part because of its rather conspicuous 3,000-mile migration across the U.S. to Mexico in late summer. Symbolizing transformation, resilience, and freedom, the monarch is also an ecological indicator species. Its struggles due to habitat loss, pesticide misuse, and climate change are considered representative of the broader picture for what wildlife and ecosystems are facing. These misfortunes have prompted wide-scale public interest in conservation, and in the restoration of monarch habitats specifically. And that means more interest in milkweeds!

Milkweeds support more than monarchs. Many Asclepias are also host plants for caterpillars of queen and soldier butterflies and are also important to some moth species, including the dogbane tiger and the milkweed tussock. Being a host plant to Lepidoptera (the order that includes butterflies and moths) means that the larval-stage caterpillars of these insects feed on vegetative parts of the plants. These larvae are able to tolerate the milkweed’s cardiac glycosides. The plants’ flowers are a food source too, visited for their nectar and often their pollen as well by other moths and butterflies (including swallowtails and fritillaries), honeybees, native bees, wasps, flies, and hummingbirds. Milkweeds are frequently cited as valuable additions to prairie and wetland habitat restoration projects, filter strips for bodies of water, and ornamental plantings in general.

Online Store Logo
Need Help? Call 1-800-234-3368