This perennial grows to a height of 3-5 feet in full sun and moist soil conditions. It has tiny flowers in spherical umbels and attracts butterflies in July and August. 'Cinderella' is a cultivar with deep pink buds and sepals, which contrast with very pale pink crowns. The leaves are narrow, lanceolate, and smaller than those of the common milkweed. The narrow seedpods usually grow in pairs. When the pods split open, the wind sends the silky tufted seeds airborne. It can be used as a specimen in a border or butterfly garden and is resistant to deer. Swamp milkweed is a native plant found growing through much of eastern and central North America. Like other milkweeds, it attracts all sorts of insects.