Drought tolerant native rhizomatous perennial with rose-purple flowers, blooming May to September. Occurs in well-drained soils of open meadows, roadsides and ditchbanks; up to 10,000 ft. elevation. Usually 2-4 ft. tall. Robust species, tolerant of a variety of environments. Forms vigorous colonies, making it useful for stabilizing degraded or disturbed soils. May become weedy, displacing other vegetation. The most abundant milkweed species in the Great Plains and western U.S. Hybridizes with Common milkweed (A. syriaca). Excellent nectar for pollinators, attracting hummingbirds, butterflies, honeybees, native bees and various beneficial insects. Larval host of the Monarch butterfly.