Seeds from Asclepias perennis, also known as Aquatic Milkweed and White Milkweed. This perennial milkweed is a great selection if you are building a butterfly garden. It grows about 2 feet high and loves to live in the full sunshine. This guy blooms repeatedly from early spring through Fall, and likes consistently moist soil. This is a host plant for the Monarch Butterfly. USDA Hardiness Zones 6 to 9