Cirsium eatonii

Cirsium eatonii, commonly known as Eaton's thistle or mountaintop thistle, is a North American species of flowering plants in the family Asteraceae.

The species has been found in Idaho, Montana, New Mexico, Wyoming, Nevada, Utah and Colorado.

Description
Cirsium eatonii is highly variable. It is an erect herb up to 150 cm (60 inches or 5 feet) tall in some populations. The entire foliage is more or less spiny. One plant produces several flower heads with pink to purple or yellow flowers. The species grows at high elevations in grasslands, sagebrush steppes, open savannahs, etc.

A number of varieties have been identified, which include:
 * Varieties
 * Cirsium eatonii var. clokeyi - Clokey thistle, Spring Mountains thistle, white-spine thistle. This variety is rare and uncommon. - Nevada
 * Cirsium eatonii var. eatonii - Nevada, Utah
 * Cirsium eatonii var. eriocephalum - alpine thistle, mountain thistle - Colorado, New Mexico, Utah
 * Cirsium eatonii var. hesperium - tall mountain thistle - Colorado
 * Cirsium eatonii var. murdockii - northern mountain thistle - Colorado, Idaho, Montana, Nevada, Utah, Wyoming
 * Cirsium eatonii var. peckii - ghost thistle, Steens Mountain thistle - Nevada, Oregon
 * Cirsium eatonii var. viperinum - Snake Range thistle - Nevada