Cirsium eatonii

(Eaton’s Thistle)

_DSC1056%20copy

Cirsium eatonii, Hoosier Ridge, Summit Co. 4761

_DSC1056%20copy

Cirsium eatonii, Hoosier Ridge, Summit Co. 4819

_DSC1056%20copy

Cirsium eatonii, Hoosier Pass, Park Co. 5270

_DSC1056%20copy

Cirsium eatonii, French Pass, Summit Co. 04949

_DSC1056%20copy

Cirsium eatonii, Hoosier Ridge, Summit Co. 4752

_DSC1056%20copy

Cirsium eatonii, Hoosier Ridge, Summit Co. 4749

_DSC1056%20copy

Cirsium eatonii, French Pass, Summit Co. 04947

_DSC1056%20copy

Cirsium eatonii, French Pass, Summit Co. 04952

Scientific Name Cirsium eatonii USDA PLANTS Symbol CIEA
Common Name Eaton's Thistle, Mountaintop Thistle ITIS Taxonomic Serial No. 36365
Family Asteraceae (Sunflower) SEINet
Reference
Click Here
Description Life zones and habitat: Montane to alpine (9500 to 13000 ft.); open areas, common on rocky alpine slopes.
Plant: Upright biennial/perennial, 8 to 28+ inches tall.
Leaves: Oblong leaves 1/2 to 2 inches wide and 4 to 14 inches long, deeply pinnately-lobed, with spines at the tip of each lobe; smooth or slightly hairy above, woolly-hairy below.
Inflorescence: Spiny bracts around flower heads give white appearance to flowers; central disk florets lavender to purple 3/4 to 1 inch long; no ray flowers.
Bloom Period: July to September.
References: "Flora of Colorado" by Jennifer Ackerfield, SW Colorado Wildflowers and Larimer County Department of Natural Resources.
BONAP Distribution Map

Colorado Status:
Native

© Tom Lebsack 2022

Banner photo: Ten Mile Range and Rhodiola integrifolia (King’s Crown) in Summit County