Smooth Milkweed, also known as Sullivant’s Milkweed and Prairie Milkweed, is native to central United States from Oklahoma to North Dakota and east to Ohio. It grows best in medium to medium-moist soils that receive full sunlight where it can grow 3-5 feet in height. Smooth milkweed closely resembles Common Milkweed, however, it is primarily hairless and the leaves are quite smooth when comparing the two. It is also not as aggressive and can be a better choice in gardens where maintenance is an issue. Globe shaped inflorescences are composed of many pink flowers that are frequented by hummingbirds and butterflies when in bloom from June-August. 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.