Pleurisy Root

Scientific Name: Asclepius tuberosa

Also Known as: Butterfly weed, orange milkweed, silkweed, chigger flower

Part used: Root

Native to: Canada (eastern and midwestern) and United States (eastern and southern)

Some Traditional Uses:  Pleurisy, other chest conditions

Current Medicinal Uses and Purposes: A tonic herb. Expectorant; increases perspiration; relieves spasm. Used internally for pleurisy, bronchitis, asthma, dry cough, pneumonia, gastritis, rheumatic fever, and uterine disorders. Used externally for inflammation, bruises, wounds, ulcers, and rheumatism.

Side Effects and Contraindications: Not for pregnant women. Plants in the Asclepius genus contain cardiac glycosides, so avoid use of pleurisy root if taking heart medications such as beta-blockers.

Listen to the Plant Detective radio show about Pleurisy root!


Photo courtesy of Pam (10.July.2006)

The plant known as pleurisy root is no longer used medicinally on a large commercial scale, which is good since this species is having a hard time surviving in the North American wild. For over a thousand years, indigenous North Americans including the Menominee, Delaware, Cherokee, Mohegan, Iroquois, Navajo, Omaha, Rappahannock, and Ponca used pleurisy root for lung and respiratory infections and other ailments and also for rope and weaving.

The genus Asclepius is named after Asklepios, the Greek god of medicine. 

Pleurisy root is threatened in some places, particularly the northeastern United States. It may be gone from the wild in the state of Maine, and it appears to be struggling in Vermont, New Hampshire, and New York. The more humans use and develop wild land, the fewer places pleurisy root can find to live.

Pleurisy root's nickname, butterfly weed, is due to the liking that butterflies, particularly their caterpillars, show for the plant. Monarch butterflies lay their eggs on pleurisy root plants so that when their larvae emerge, the caterpillars have a nice feast in front of them! In general, plants in the milkweed family contain compounds that are toxic to most animals, but not to monarchs. Predators know not to eat monarch larvae or even adult butterflies, who continue to carry the toxin. Butterflies that LOOK like monarchs capitalize on this protection, since predators often avoid them as well.

The brightly-colored larva of a Monarch butterfly feeds on an Asclepias milkweed plant. Photo courtesy of Alex Wild (

Pleurisy root eases inflammation and encourages expectoration (the coughing up of mucus). Newcomers on the North American continent learned about the plant from Indian people, and in the 18th century pleurisy root was adopted into the mainstream pharmacopoeia. Because of its gentle effectiveness, a few herbalists still use pleurisy root today for patients, but since there are many good substitutes and the plant's status in the wild is threatened, most use other plants.

What is pleurisy, anyway? It's the old-fashioned term for chest pain caused when the membrane around your lungs becomes inflamed.

Blowin' in the Wind

Photo courtesy of Pam (10.July.2006)

Pleurisy root seed pods are generally large and contain hundreds of seeds, each with a silky-soft, fluffy parachute called a coma. Their comas allow the seeds to float in the wind and find new places to grow. People used to stuff pillows and clothes with the seed fluff and even use them to make lifevests. They also used the seed fluff as wicks in candles.

Pleurisy Root References

Bown, Deni. Encyclopedia of Herbs and Their Uses. New York: Dorling Kindersley Publishing, 1995.

Judy, Beth. Medicinal Plants of North America: A Flora Delaterre Coloring Book. Missoula, MT: Flora Delaterre Productions, 2007.

Yarnell, Eric. Asclepias tuberosa L (Pleurisy Root), Asclepiadaceae and Related Species. Monograph. Bastyr University, Department of Botanical Medicine, 2006.