The Butterfly Weed

MISSOURI NATIVE SPECIES | JULY 14, 2020

The next installment of my Missouri Native Species Collection is the beautiful Butterfly Weed, Asclepias tuberosa. I have been waiting all Summer for migratory butterflies to begin descending upon Missouri. The blooming of important milkweed species like the Butterfly Weed will help to entice travelers as they prepare for their transcontinental journey.

This brightly colored nectar powerhouse attracts a variety of insects and even hummingbirds. While Asclepias tuberosa may not always be the top choice of Monarch Butterflies, Monarch caterpillars will happily rear and feast upon Butterfly Weed.

Named for the Greek God of Medicine, Asclepius, Butterfly Weed is both medically useful and incredibly important to butterflies and other insects.

Characteristics of the Butterfly Weed

BINOMIAL NAME: Asclepias tuberosa

FAMILY: Apocynaceae (milkweed, flowering dogbane)

Butterfly Weed is an herbaceous perennial native to the United States. Most commonly found in the southern areas of America, this drought-tolerant milkweed plant serves as both a host and nectar plant for various butterflies. Plants grow in clumps 1-2′ tall and flowers bloom from May through September. Adaptable to various soil conditions, this hearty plant prefers proper water drainage and thrives in bright sunlight.

Asclepias tuberosa is a showy and vibrantly beautiful member of the milkweed family. Plants develop from a single, unbranched stem. Stems become branched near the top, where the brightly colored flowers develop. Each flower contains five of each sepals, petals, and hoods. The primary reason this plant is referred to as butterfly “weed” versus butterfly “milkweed” is the notable absence of a milky latex which is present in other species of milkweed.

The secret to the Butterfly Weed’s success among drier, arid conditions lies underground in the plant’s woody tap root system. Thick and knobby, roots extend several feet into the ground providing a secure anchor for each plant. While Butterfly Weed is easily propagated by seed and rhizome cuttings, it is sensitive to uprooting and therefore can be difficult to transplant.

Milkweed Bugs (Oncopeltus fasciatus, Lygaeus kalmii)

While observing these plants I did not see butterflies or caterpillars, but I did find plenty of Milkweed Bugs. Milkweed bugs are piercing, sucking insects that feed on plant seeds by piercing seed pods with their long proboscis. These bright-orange bugs will also feed on milkweed leaves and stems. Milkweed bug bodies absorb the plant’s toxic compounds while ingesting milkweed sap making them rather unpalatable and are often avoided by predators as a result.

Most of the bugs I found were still in the nymph stage and were not yet wing-bearing adults. Because of their close color to the orange milkweed, I almost did not notice them. Upon closer inspection, they are rather cute.

Medicinal & Culinary Uses

Humans have a long history of harvesting milkweed plants for medicinal and textile use. Native Americans used the thick, fibrous stems to weave cloth and make ropes and cordage. Archaeologists have found remnants of stem fibers in the prehistoric textiles of the Pueblo region. It is noted that the Tewa-speaking peoples of Rio Grande continue to use Butterfly Weed stems to create string and rope.

Native Americans and early settlers used the roots of Butterfly Weed to treat pleurisy, hence the nickname “Pleurisy Root”. Pleurisy is a condition that causes the lining of the lungs to become inflamed. Butterfly Weed root stimulates the vagus nerve producing bronchial dilation, relieving those with bronchial troubles. Pleurisy Root helps with fluid circulation, lymphatic drainage and cilia function. Results of using the plant were so effective that the root was listed in the U.S. Pharmacopoeia from 1820 to 1905, and in the National Formulary until 1936.

Like other species of milkweed, Butterfly Weed sap contains chemicals toxic to animals, particularly, cattle and sheep. Protective cardiac glycosides like asclepione and asclepiadin can be harmful to mammals if ingested in large quantities. The toxic compounds absorbed into caterpillars via ingestion creates a naturally protective deterrent to predators. A. tuberosa does contain lower levels of the toxic compound compared to other milkweed species, however it is still quite effective in protecting caterpillars from predation.

People have harvested and used the edible seed pods and matured flowers in culinary cuisine for ages. Flowers have a taste resembling sweet peas, when cooked.

Butterfly Weed is one of the most versatile plants on our planet. These beautiful plants don many wildflower gardens across the country, providing sustenance to Monarch caterpillars and other important pollinators. The unfortunate widespread use of herbal pesticides has damaged milkweed plant populations and by extension, has contributed towards a decline in monarch populations.

Because of its importance to the monarch species in particular, propagation of Butterfly Weed is heavily encouraged to gardeners. Hardy, healthy, and low maintenance, the Butterfly Weed is a garden must-have that is as beautifully ornamental as it is use incredibly useful.