Eryngium yuccifolium is a moderate sized yucca with thistle-like flowers sprouting from an erect inflorescence stem. These tend to grow in prairies, where they can self-seed under proper conditions. They cannot be transplanted, usually, due to their deep tap root. These plants have been used to help subdue venom from rattlesnakes.
Eryngium yuccifolium (Rattlesnake Master, Button Snake-root, Button eryngo)
Hardiness Zones: 3-8
Height: 4-5 feet tall
Diameter: spreads 2-3 feet
Growth Rate: moderate
Root System: The tap root extends deep into the soil, making this plant difficult to transplant.
Subspecies: ‘Kershaw Blue’
Tolerates: drought, erosion, clay soil, dry soil, rocky soil, shallow soil
Problems (major): no major issues
Problems (minor): Taller plants may need support to stay upright.
Poisonous: presumably no
Soil requirements: good drainage is necessary, dry and sandy soils are preferred
Air Requirements: not sufficiently researched
Watering requirement: dry or medium
Sun requirement: Full sun is preferred, part-shade is acceptable.
Leaf shape: sword-shaped, yucca leaves
Leaf size: up to 0.9 meters (3 feet) long
Flower structure: The flowers are tiny, and stemless with green-white flowers. The individual flowers are similar to thistle flowers with two stigmas, five anthers, five greenish sepals, and five white petals. The flowers are around an inch across. Flower heads grow vertically from the rosette’s base, 3 to 6 feet tall.
Flowering frequency: Flowers from middle to late summer.
Bulb/tuber: deep taproot
Rattlesnake Masters can self-seed somewhat profusely under optimal conditions.
This plant was once used a cure for rattlesnake bites, hence its common name.
All of the images provided were taken by me. They may be used for educational/informational purposes only provided that this article/blog is appropriately cited first.