Allium cernuum, known as nodding onion or lady's leek, is a perennial plant in the genus Allium. It grows in dry woods, rock outcroppings, and prairies. It has been reported from much of the United States, Canada and Mexico including in the Appalachian Mountains from Alabama to New York State, the Great Lakes Region, the Ohio and Tennessee River Valleys, the Ozarks of Arkansas and Missouri, and the Rocky and Cascade Mountains of the West, from Mexico to Washington. It has not been reported from California, Nevada, Florida, Louisiana, Mississippi, New Jersey, Delaware, New England, or much of the Great Plains. In Canada, it grows from Ontario to British Columbia.