Butterfly Weed

Asclepias tuberosa

butterfly weed

Butterfly weed, photographed at Riverbend Park, Jupiter, Palm Beach County, in June 2021.

It's well known that butterfly weed, Asclepias tuberosa, is one of a number of milkweeds that serve as host to the larvae of the monarch butterfly, queen butterfly and other members of the genus, Danaus. More surprising is the extent to which it's been used in both traditional and western medicine.

In fact, one of its common names is pleurisy root because of its use as a treatment for inflammation of the lungs. But that is only one of many medicinal uses for butterfly weed. More on that in a bit, but first some botantical basics.

Butterfly weed is widespread throughout most of the United States, with the exception of the Northwest. It's also found in eastern Canada and northeastern Mexico. In much of New England, however, it's on the rare side. It's believed to extirpated, or locally extinct, within Maine; New Hampshire lists it as endangered, for example.

It is a Florida native, but the Institute for Regional Conservation in Delray Beach considers it rare within our area. Butterfly weed is more prevelant in the central and northern parts of the state.

Butterfly weed is an important food source for both monarch adults and larvae, or caterpillars. Monarchs and other butterflies sip nectar from the flowers, as they do many other flowers. But larvae are picky eaters for a very good reason. Adult females will lay their eggs only on butterfly weed and other members of the milkweed family. The reason: these plants are loaded with cardiac glycosides, a group of poisonous chemicals. By eating the leaves of butterfly weed, monarch larvae and adults become poisonous themselves. Glycosides are also the reason why monarchs are bright orange, which is critical to their defensive system.

It is a shrubby plant, a foot or two tall, and spreading about the same. The leaves are simple, oblong, between four and eight inches in length, arranged alternately along the stem and "entire" or smooth, along the edges. The flowers generally are orange but can range from yellow- to red to bright orange. They bloom all year in South Florida. The flowers give way to pods full of puffy seeds that are dispersed by the wind. Favorite habitats include prairies and open woods. It is grown by gardeners to attract butterflies but it will also attract hummingbirds.

As we said above, butterfly weed was an important element in traditional medicine for many native American tribes, including the Cherokee and the Navajo. Various parts of the plant were used as to relieve stomach, intestinal or breast pain, for diarrhea, pleurisy (inflammation of the lining of the lungs), heart problems, as a laxative, to treat rheumatism, the flu and dog bite, as a ceremonial lotion, as a gynecological aid and as a tonic.

The root of butterfly weed became such an established part of the western medicine cabinet that it was included in the U.S. Pharmacopoeia until 1905 and the National Formulary until 1936. Both are standards organizations of sorts for medicines.

In Appalachia, westerners used butterfly weed to treat smallpox. Extracts and tinctures are still available on the internet. One thing to remember is that all parts of butterfly weed are poisonous, although a considerable quantity needs to be consumed for it to be fatal.

But butterfly weed's usefulness didn't end there. Native American tribes wove fibers from the stems into cloth and cord. Even the silky threads from butterfly weed seeds have been — and still are — woven into cloth. Young parts of the plant were eaten as food. (A reminder: All parts of the plant are toxic.)

Other common names include butterfly milkweed. butterfly milkweed, orange milkweed, pleurisy root, chigger flower and Indian paintbrush. It is a member of Apocynaceae, the dog bane family. Some references, including the U.S. Department of Agriculture still place it as a member of an old classification, Asclepiadaceae, however.

Photo Gallery — Click on photo for larger image

U.S. Department of Agriculture Distribution Maps

Published by Wild South Florida, PO Box 7241, Delray Beach, FL 33482.

Photographs by David Sedore. Photographs are property of the publishers and may not be used without permission.