Of Butterflies on Milkweed

By Steven Foster |

Butterflyweed Asclepias tuberosa in Lawrence, Kansas
Butterflyweed Asclepias tuberosa in Lawrence, Kansas

It’s milkweed season in the Ozarks and elsewhere in North America. There are over 100 species of milkweeds, members of the genus Asclepias, named by Linnaeus in 1753 after the Greek god of healing, Asclepius. Conspicuous among milkweeds now blooming is Asclepias tuberosa—butterflyweed, pleurisy root, or chiggerweed—with its brilliant showy orange flowers. I assume the name chiggerweed refers to the fact that our friendly little flesh-eating spider-relatives enjoy living on the plant. The larger tuberous root is used medicinally to treat inflammatory lung conditions, hence the name pleurisy root. If you spend time around one of the plants with camera in hand, inevitably one of the most beautiful of our native wildflowers attracts butterflies in addition to photo seekers.

Butterflyweed, and a couple dozen other North American species of milkweeds attracted widespread media attention last fall when monarch butterflies failed to show-up in the winter home of oyamel fir forests in Central Mexico. The spectacle of millions of monarchs

Common milkweed, Asclepias syriaca
Common milkweed, Asclepias syriaca

covering trees in their winter home in Mexico since time immemorial was replaced last year by a few thousand monarchs fluttering about trees. Monarch larvae feed exclusively on milkweeds, sequestering bitter and potentially toxic cardenolides which deter predators from feeding on the butterflies as they make the journey south each winter. Monarch numbers declined by 59% from 2012 to 2013. One of the major factors relative to the decline is the dramatic loss of habitat for milkweeds, with 160 million acres consumed by agricultural or suburbia over the last 17 years alone.

Asclepias-syriaca-61414_408Public awareness about the decline of monarch butterflies has translated into awareness of milkweeds — the food of monarch larvae. In 2014 various organizations have been distributing seed or plants of the dozen or more species of Asclepias found in our area and coaxing them to plant milkweeds. One of the main milkweeds found in the eastern U.S., is called appropriately common milkweed Asclepias syriaca. This species seems to be the favorite food of monarch larvae.

The analogy of chaos in nature as characterized by the flapping of a butterfly’s wing in the Amazon affecting weather elsewhere demonstrates the interconnectivity of all living things. Without habitat we have no milkweed. Without milkweeds we have no monarch butterflies. Without humans nature maintains balance. Pay attention to life on earth.

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