All around the Albany Pine Bush Preserve, milkweeds are blooming. Milkweeds get their name from the eye-catching, milky sap that seeps out of any part of the plant that is injured – even the petals! They are also excellent sources of nectar for butterflies, bees, beetles, and other insects. For a visual treat, take a moment to look closely at the tiny blossoms of a milkweed plant and the colorful insects they attract.
Just as wild blue lupine is among the only plants Karner blue butterflies and frosted elfin butterflies can eat, common milkweed is essential food for certain other insects. Insects that specialize in eating milkweeds including the red milkweed beetle, milkweed leaf beetle, and the larvae (caterpillars) of the monarch butterfly. These insects depend on common milkweed not only for food, but for chemical defense!
The very sap that gives the milkweed its name is full of chemicals called cardiac glycosides, which are poisonous to most animals, including humans (fortunately for us, the sap is not dangerous unless we eat it). The insects that eat milkweed have special digestive systems, which extract and store the toxic chemicals from the sap in the insects’ bodies. If a bird or other predator attempts to eat one of these milkweed-specialist insects, the stored chemicals in the insect’s body will cause the insect to taste bad and the predator to vomit. From such an unpleasant experience, the predator will learn to avoid that type of insect in the future.
At the Albany Pine Bush Preserve, two different types of milkweed – common milkweed and butterfly milkweed – are relatively abundant and can be spotted from the hiking trails and in the planting beds around the Discovery Center. Common milkweed has pink or purplish flowers and broad leaves, whereas butterfly milkweed has orange flowers and narrow leaves. Butterfly milkweed also tends to be somewhat shorter and more branched than Common milkweed. Butterfly milkweed is unusual among the milkweeds because its sap is clear instead of milky. According to Albany Pine Bush Preserve Botanist, Jesse Hoffman, clasping milkweed and swamp milkweed can also be found at the Albany Pine Bush Preserve. You can learn more about milkweeds at http://scienceviews.com/plants/milkweed.html and take a look at some beautiful close-up images of milkweed plants here.