This is Liatris squarrosa, also known as Scaly Blazing Star, Colic Root, Rattlesnake Master, and Button Snakeroot. This perennial can get about 2 feet high and it attracts a great number of birds, bees, and butterflies. It likes to live in sun or partial shade where it blooms from late Summer until the middle of Fall. In some areas this plant is considered a protected species. USDA Hardiness Zones 4 to 9