Eryngium yuccifolium, commonly known as button snake-root or rattlesnake master, is an evergreen perennial forb native to Missouri. Part of the tallgrass prairies, the plants occur in rocky woods, glades, and prairies. They mostly grow in certain regions of North America, Texas, Florida, Minnesota and Ohio.The rattlesnake master is hermaphrodite and produces greenish-white flowers from July to September. However, when not flowering, the plants form a rosette of sword-shaped, fibrous leaves that resemble those of yucca, hence the name.