Swamp Milkweed is widely distributed across the United States where it inhabits wet meadows, swamps marshes, pond edges and stream banks. Although it does best in moist soil conditions, it will grow in drier soils such as upland prairies, field edges and ditches. This long-lived perennial prefers to grow in full sunlight and can reach 3-5 feet in height during its second year of growth. Blooming from June-September, the flowers can be pink, purple, or even white. The globe shaped inflorescences attract many hummingbirds, bees and butterflies who seek the nectar from the flowers. All parts of the plant are toxic to livestock and humans, although many Native American tribes ingested it for medicinal uses. If the plant is broken, such as having a leaf removed, it produces a milky white sap from the wound, although not as much as some of its relatives.