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whorled milkweed
whorled milkweed (Asclepias quadrifolia)
Photo © Christopher David Benda
Features and Behaviors
FEATURES
Whorled milkweed is also known as four-leaved milkweed. This perennial herb grows from a thickened root. Its upright stem is unbranched and smooth or a little hairy. The stem has milky sap. The leaves in the middle section of the stem are in whorls of four. Upper stem leaves may be in pairs. Each simple, lance-shaped leaf may be six inches long and three inches wide. Flowers are produced in domed, umbrellalike clusters at the stem tip. Flowers may be pink, purple or white. Each flower has five, downward-pointing petals supporting a crown of five, inward-pointing hoods. The fruit is a long, pointed seedpod. Whorled milkweed may attain a height of one to two feet.
BEHAVIORS
Whorled milkweed may be found in the southern two-thirds of Illinois. It grows in rocky, open woods. Flowers are produced from May through July.
Illinois Range
Taxonomy
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Gentianales
Family: Apocynaceae
Illinois Status: common, native
