Habit: growing in clumps, this winter-dormant milkweed is hairless with ascending stems and large smooth, leaves that are bluish green with purplish tints. The leaves clasp the stem and have an elongated heart shape (cordate). Purple flower buds are borne on several short stalks that extend some distance from the leaves, and open to deep magenta stars with pale centers. The flowers blooms between May and July and give off a sweet slightly honey scented fragrance. The flowers are followed by curious purple, tear-drop shaped seed pods containing many flat seeds with silky hairs which disperse easily in the wind.
Ecology: found on dry rocky slopes, in open or shaded woodland and mixed coniferous forests from sea level to 7500 ft (50-2300 m)
Growing Conditions: full sun, in rich well-drained soil. Asclepias cordifolia will tolerate moderate amounts of water during the growing period.
Heartleaf milkweed are attractive to butterflies, bees, and other insects. Similar to other milkweeds, when broken a milky sap oozes out.