Rattlesnake Master is an interesting oddity for unusual perennials borders, with grayish green spiny leaves from which spring its very tall flower spikes in July and August. The blooms are a pale silvery blue and look somewhat like round thistles. Tolerant of both dry and moist conditions, this dramatic looking native got its name from the formerly held theory that its sap cured rattle snake bites. As Dr. Alan Armitage says so succinctly, "Fat chance". Butterflies love it.