This is a tall and conspicuous species that sometimes forms large clones. The umbels bear large balls of pink to purplish flowers that have an attractive odor.

Fun Fact: The plant contains cardiac glycosides, allied to digitalins used in treating some heart disease. These glycosides, when absorbed by monarch butterfly larvae whose sole source of food is milkweed foliage, make the larvae and adult butterflies toxic to birds and other predators!