Cirsium scopulorum
(Mountain-top Thistle)
Cirsium scopulorum, Loveland Pass, Clear Creek Co. 1567
Cirsium scopulorum, Loveland Pass, Clear Creek Co. 1561
Cirsium scopulorum, Loveland Pass, Clear Creek Co. 1596
Cirsium scopulorum, Loveland Pass, Clear Creek Co. 1597
Cirsium scopulorum, Loveland Pass, Clear Creek Co. 1576
Cirsium scopulorum, Loveland Pass, Clear Creek Co. 2883
| Scientific Name | Cirsium scopulorum (Cirsium eatonii var. eriocephalum) | USDA PLANTS Symbol | CISC3 |
| Common Name | Mountain-top Thistle, Alpine Thistle | ITIS Taxonomic Serial No. | 780840 |
| Family | Asteraceae (Sunflower) | SEINet Reference |
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| Description |
Life zones and habitat: Subalpine and alpine (10500 to 13500 ft.); open areas, tundra, scree, meadows, windswept alpine ridges. Plant: Upright perennial, 8 to 32 inches tall; stout, spiney stem. Leaves: Basal and stem leaves, lanceolate 1 to 13 inches long, deeply pinnately-incised with lobes tipped by spines 1/2-inch long; smooth above, woolly-hairy below. Inflorescence: Densely-packed clusters of often nodding, very hairy flower heads that can extend on the stem nearly to ground level; light pink to purple disk florets in the center; no ray flowers; involucres with very white, densely-hairy, spiney phyllaries 3/8 to 3/4-inch long. Bloom Period: July to September. References: "Flora of Colorado" Second Edition by Jennifer Ackerfield, "Guide to Colorado Wildflowers" by G.K. Guennel and SEINet. Note: In the research document Thistle be a mess: Untangling the taxonomy of Cirsium (Cardueae: Compositae) in North America by Ackerfield, et al, C.eatonii var. eriocephalum becomes C. scopulorum. |
BONAP Distribution Map Map Color Key |
Colorado Status: Native |
© Tom Lebsack 2024
Banner photo: Ten Mile Range and Rhodiola integrifolia (King’s Crown) in Summit County