Rattlesnake Master (Eryngium yuccifolium) is an erect plant that grows to 3 feet high or taller. Its leaves are reminiscent of those of the yucca plant- long, linear, sharply-pointed and with parallel veins. Its button-like white flowers grow on a central, branched stalk. The flower heads are 1/2 to 3/4 inch in diameter and are covered with a multitude of tiny white or greenish flowers which bloom from May to August. Rattlesnake Master prefers full sun in moist, well-drained soils.