Eryngium yuccifolium

rattlesnake-master, button snakeroot, yuccaleaf eryngo, button eryngo, beargrass, bear's grass


Leaf Arrangement


Leaf Attachment


Leaf Margin

entire, spinose

Leaf Type


Leaf Shape


Growth Form


Flower Color

green, white

Flower Petals


Flower Month

May - August

Height (meters)

0.2 - 1.8

Milky Sap








Growing Season

Warm season

Wetland Class


Prairie Coefficient of Conservatism


Field Characters

Distinctive, bristly, yucca-like basal leaves distinguish it from other species.

Cultural Information

The seeds are dark brown, oval-shaped and 1/4" long. They ripen in the fall when the heads turn dark brown. When the seeds become loose in the head, cut the heads and dry in paper bags. Store under cool, dry conditions. There are 128,000 - 199,000 seeds/lb and should be planted at a rate of 10 lbs/acre. Dormancy is often induced by storage, so stored seeds should be cold/moist stratified at 33-38 degrees F for 30-60 days (Phillips 1985, Shirley 1994, Steffen 1997). Plants bloom in 1-2 years from seed. Additional rosettes or "pups" will develop around the base of older plants. These can be separated and planted in the fall, taking care not to disturb the root system. Button Snakeroot prefers moist soil but is tolerant of wet to dry sites and a pH of 5-7.5. It is difficult to transplanting due to its large taproot. Appears in saline prairie in south Texas, which indicates it has some salt tolerance.

Animal Use

New growth is acceptable to cattle as forage. Attracts a great variety of pollinators. Rabbits and deer like the young leaves (Shirley 1994).

Natural History

A warm-season, deep-rooted forb described by Weaver as an upland species which prefers sandy, well drained sites (Weaver and Fitzpatrick, 1935). However, it grows in salty, gulf cordgrass prairie near the coast in Texas. It is found throughout the tallgrass prairie region growing on a variety of soil types. The flowers have a sweet, honey-like smell and attract a wide range of pollinators. The new growth is palatable to livestock, and it is a decreaser under heavy grazing. The genus eryngium has been used as medicine since the time of Hippocrates. Extracts of the roots were recommended by 16th century English doctors for liver trouble and other ailments common to older people. Leaf fibers were used to make cordage and sandals. Native Americans used it to treat snake bites hence the common name "rattlesnake master."


Prairies and rocky open woodlands.