Common Milkweed

Kendall County (IL) Forest Preserve District

Common Milkweed (Silkweed)
Asclepias syriaca [C-value 0]
Milkweed Family (Asclepiadaceae)
Blooms mid-June - August

The very valuable native Common Milkweed is common in our area, and is a favorite larval host plant for the Monarch Butterfly (see note below). It prefers full sun and moderately moist rich loamy soil. This perennial is 2-6' tall and unbranched with a relative stout, pale green central stem. Its opposite, untoothed and broadly oblong-shaped leaves are up to 8" long and 3½" wide with the undersides densely covered with very short woolly hairs. Spherical umbels of flowers, 2½-4" across, emerge from the axils of the upper leaves. These flowers range in color from faded light pink to reddish purple and are very fragrant. Each flower is about ¼" across with 5 petals and 5 raised hoods with curved horns.

Common Milkweed flower heads at Harris Forest Preserve back pond June 29, 2013

Common Milkweed needs cross pollination to produce fertile seeds.

Common Milkweed seed pods at Harris Forest Preserve back pond June 29, 2013

Common Milkweed colony at Harris Forest Preserve back pond June 29, 2013

Common Milkweed foliage at Oswego Pres. Ch. Monarch Waystation July 14, 2017

When a stem or leaf is torn, a milky white sap oozes out - hence the common name.

Common Milkweed fall seedpods at Oswego Library Montgomery Campus October 26, 2014

At maturity, each seedpod splits along one side to release numerous seeds with tufts of white hair which get dispersed by wind.

Common Milkweed fall seedpods at Oswego Library Montgomery Campus October 26, 2014

Additional note: Plants of the Milkweed family are exclusive larval host plants for the Monarch Butterfly (Danaus plexippes). The Monarch caterpillars only feed on the foliage of Milkweeds (see picture below) which is toxic to birds and other insects so caterpillars and resultant butterflies are in turn shunned by birds and other predators. The extensive use of herbicides in corn and soybean fields here in the Midwest has greatly reduced field-edge habitats for Milkweeds which in turn reduces the populations of Monarchs.

A baby Monarch Butterfly caterpillar (about 1/2 inch long) on Common Milkweed leaf at Oswego Pres. Ch. Monarch Waystation August 20, 2017

As noted above, the Monarch Butterfly (Danaus plexippes) has a special unique relationship with the Milkweeds as birds learn to shun these plants and anything feeding on them. Some beetles make their summer homes only on milkweeds to get this protection from birds and other predators.

Native Americans used Milkweed as a food and medicine, but it can be toxic to humans if not prepared properly (per Sanders, J). The young shoots, stems, flower buds, immature fruits, and roots of butterfly milkweed were boiled and eaten as a vegetable by various indigenous groups of eastern and mid-western America. The Meskwaki tribe steamed the flower buds as a food source, which was nutritious but not considered very flavorful. The Cherokee drank an infusion of common milkweed root and Virgin's Bower (Clematis species) for backache. They also used the plant as a laxative, an antidote for dropsy, and an infusion of the root for venereal diseases. The Meskwaki and Mohaw used a decoction as a contraceptive; the Iroquois and Navajo to prevent problems after childbirth; and the Chippewa, to produce postpartum milk flow. Other uses included treatment for stomach problems, female issues, chest discomfort, and externally on warts and bee stings. Reminder: see Do Not Disturb Notice.

The pioneers used the seedpods' “cotton” as pillow stuffing, and during World War II, schoolchildren were paid 15¢ per big "potato bag" of seedpods they collected and the “cotton” was used in life preservers for the U.S. Navy.

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