Rattlesnake Master  features basal rosettes of parallel-veined, bristly-edged, sword-shaped, medium green leaves (to 3' long) resembling those of yucca and tiny, stemless, greenish-white flowers tightly packed into globular, 1" diameter heads resembling thistles. Flower heads appear in branched clusters at the top of smooth stiff stems typically rising to 3-4' tall from the centers of the rosettes. The blooms are attractive to butterflies and other insect pollinators.