This perennial grows to a height of 3-5 feet in full sun and moist soil conditions. It has tiny fragrant flowers in various shades of pink and white and attracts butterflies in July and August. 'Soulmate' is a selection with rosy pink flowers centered with a white staminal column. 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 in marshy areas through much of eastern and central North America. Like other milkweeds, it contains a toxic, milky sap and attracts all sorts of insects.