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Milkweed plant
Swamp Milkweed

Q: Where does the milkweed plant get its name?

A: It leaks a thick, white sap when cut or broken that makes it look like it's leaking milk.

Common Milkweed - The Facts

Height: grows from 2-6 feet high. It usually has a single, simple stem.

Leaves: are opposite, oval-shaped and 2-10 inches tall. The top surface of the leaf is smooth, but the bottom surface is hairy.

Flowers: bloom from late June to August, pink to lavender in color, and are found in bunches. The main flower is actually a bunch of little flowers on the same stalk.

Fruit: in the fall, flowers develop into seed pods. The pods have a warty outer skin filled with downy fluff that will carry the seeds on the wind like a parachute.

Milkweed seed

A sure sign of summer in Wisconsin is when the common milkweed (Asclepias syriaca) is in bloom. You'll find this plant in fields, meadows, and along roadsides. If you find milkweed, you're also likely to find monarch butterflies. Monarchs need milkweed to survive. The butterfly lays its eggs on milkweed plants. The growing larvae (caterpillars) eat milkweed leaves. These leaves contain toxins- poisonous chemicals. These toxins don't hurt the caterpillar, but they do make the caterpillar poisonous to most predators. Because it eats milkweed leaves as a caterpillar, the monarch butterfly is also poisonous. The survival of the monarch butterfly depends on this self-defense system provided by the milkweed.

Did you know that...

  • Sap from milkweed was used by pioneers as a cure for warts?
  • The airborne fluffy parachute of the seed was used by Native Americans to insulate moccasins?
  • The dried empty seed pods were used as Christmas tree decorations by early pioneers?
  • The boys and girls from Wisconsin schools collected 283,000 bags of milkweed fluff for use in military life jackets during World War II?
  • It is used as an indicator of ground-level ozone air pollution? Find out how to conduct a milkweed check-up to check for signs of pollution
  • You can attract butterflies to your yard by planting a butterfly garden.