Eryngium yuccifolium (Rattlesnake Master)

Native perennial with silvery foliage and globe-shaped flowers in mid to late summer.  Grows best in dry, well drained and even poor soils.  Excellent pollinator plant. Reaches 4-5 feet tall and 2-3 feet wide.  Flower stems may need to be staked or, alternatively, may be supported by mass planting.