Cirsium griseum var. griseum
(Gray Thistle)
Cirsium griseum var. griseum, Mountain View Trail, State Forest State Park, Jackson Co. 0934
Cirsium griseum var. griseum, Mountain View Trail, State Forest State Park, Jackson Co. 0938
Cirsium griseum var. griseum, Mountain View Trail, State Forest State Park, Jackson Co. 0941
Cirsium griseum var. griseum, Mountain View Trail, State Forest State Park, Jackson Co. 0948
| Scientific Name | Cirsium griseum var. griseum (C. clavatum var. americanum, C. griseum, C. modestum, etc.) | USDA PLANTS Symbol | n/a |
| Common Name | Gray Thistle, Fringed Thistle | ITIS Taxonomic Serial No. | 780834 |
| Family | Asteraceae (Sunflower) | SEINet Reference |
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| Description |
Life zones and habitat: Foothills and montane (6900 to 10200 ft.); sagebrush scrub, grasslands, meadows and open areas in forests. Plant: Upright biennial/perennial, 8 to 40 inches tall, usually dark purple stems. Leaves: Oblong to oblanceolate or elliptic 4 to 12 inches long, deeply pinnately-lobed, with spines at the tip of each lobe; smooth or slightly hairy above, smooth to woolly-hairy below; surfaces are green to purple and may have purple midvein; blades are decurrent (extending or wrapping down the stem) for 3/4-inch. Inflorescence: Loose clusters of flower heads at stem tips or in leaf axils; central disk florets are white to pink, 5/8 to 1 inch long, and the styles are white with purple stripes; no ray flowers; outer phyllaries are longer than the inner and hairless to sparsely woolly; phyllaries have no rib along the back and have straight spines; outer phyllaries are longer than inner. Bloom Period: July to September. References: "Flora of Colorado" Second Edition by Jennifer Ackerfield, Thistle be a mess: Untangling the taxonomy of Cirsium (Cardueae: Compositae) in North America by Ackerfield, et al and Flora of North America. Note: In the research document above by Ackerfield, et al, C. griseum, C. modestum and C. clavatum var. americanum, among others, become C. griseum var. griseum. |
BONAP Distribution Map Map Color Key Cirsium clavatum var. americanum |
Colorado Status: Native |
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