The sticky white latex that flows from the leaf and stem of the plant gives common milkweed (Asclepias syriaca) its name. People have used the latex topically to remove warts, and tried to use the latex in wartime as a substitute for rubber. For the plant, the latex is a defense mechanism. The stickiness deters insects from eating the leaves, and the cardenolide glycosides in the latex are toxic. Milkweed is a poisonous plant to humans.
For insects that have evolved to make use of the toxins, the latex is a protection from predators. Birds that prey on Monarchs, the best-known of the milkweed insects, vomit after eating them. The curious thing about many milkweed insects is the red and black (or red and orange) coloring that they share, which biologists call aposematic coloration.
The milkweed plant is homely. The flowers and buds are attractive, but the thing that brings me back to milkweed again and again is the fruit: the pods, the seeds, and the floss. There’s something uncommonly beautiful about milkweed at this stage:
There’s more to show about milkweed – the butterflies and other insects that are attracted to the flowers. In my area, common milkweed flowers in July, hairstreaks, fritillaries, skippers, and moths all cluster on it. Just one example:
Milkweed is my longest-running photographic project. The photographs in this post go back a decade and more – and I finally got around to collecting my thoughts about the web of life and beauty surrounding this plant.