Cirsium clavatum (1997)
ASTERACEAE
Cirsium clavatum (M. E. Jones) Petr.
U.S.A., Colorado, Gunnison County: Northern Gunnison Basin: on Snodgrass Mountain, ca 2 air mi SSE of Gothic.
Aspen forest, open meadow, and along ponds, creeks, and seeps. Phenology: flowering & fruiting.
Annotations:
Annotated by Jennifer R. Ackerfield in 2005.
Accession: 720292

Cirsium clavatum (1997)
ASTERACEAE
Cirsium clavatum (M. E. Jones) Petr.
U.S.A., Colorado, Gunnison County: Northern Gunnison Basin: ca 4 air mi NE of Pitkin.
Lodgepole pine, Engelmann spruce forest; common juniper and Vaccinium. Phenology: flowering & fruiting.
Annotations:
Annotated by Jennifer R. Ackerfield in 2005.
Accession: 720291

Cirsium clavatum (2001)
ASTERACEAE
Cirsium clavatum (M. E. Jones) Petr.
U.S.A., Colorado, Larimer County: Roosevelt National Forest: Front Range:Comanche Peak Wilderness: Cache la Poudre River on Big South Trail off Colo Hwy 14, ca 34 air mi W of Fort Collins.
Douglas fir and aspen canopy along river with Arctostaphylos and some rock piles and overhangs. Phenology: flowering.
Annotations:
Annotated by Jennifer R. Ackerfield in 2005.
Accession: RM 765221

U.S.A., Colorado, Mesa County: Grand Mesa: Mesa Lakes.
Elev. 9600 ft.
Open aspen and spruce-fir forest. Phenology: fruiting.
Accession: RM 241732

U.S.A., Colorado, Garfield County: White River National Forest: 2 mi N of West Ranger Station.
Elev. 7400 ft.
40 degree east slope, sandy loam, woodland; with Cornus, Symphorocarpus and Polemonium. Phenology: flowering & fruiting.
Accession: RM 475961

U.S.A., Colorado, Grand County: Coulter Post Office.
T1N R76W S19; also S30
Phenology: flowering.

U.S.A., Colorado, Grand County: Middle Park: Coulter Post Office.
Phenology: flowering & fruiting.

Cirsium clavatum var. americanum (2004)
Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil
U.S.A., Colorado, Archuleta County: Eastern San Juan Mountains: northeast end of Mesa Cortado, S of U.S. Hwy 84, ca 17.5-18 air mi SE of Pagosa Springs.
Aspen meadow at the head of a drainage. Phenology: flowering & fruiting.
1. Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil
Annotated by Jeanette Flaig.
Accession: RM (unaccessioned)

Cirsium clavatum var. americanum (2003)
Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil
U.S.A., Colorado, Clear Creek County: Arapaho National Forest: Front Range: West Fork Clear Creek at Mizpah Campground, ca 12 air mi S of Fraser; ca 14 air mi WNW of Idaho Springs.
Along creek and in spruce forest. Phenology: flowering & fruiting.
with Michael Foley
Accession: RM (unaccessioned)

Cirsium clavatum var. americanum (2003)
Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil
U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Vasquez Creek, ca 3 air mi SSE of Fraser, ca 6.5 air mi NNW of Berthoud Pass.
Elev. 9000 ft.
Along creek, in spruce forest, and roadside. Phenology: flowering & fruiting.
Accession: RM (unaccessioned)

U.S.A., Colorado, Grand County: Arapaho National Forest: Williams Fork Mountains: intermittent stream between Henderson Tunnel and Williams Fork, ca 6 air mi SW of Byers Peak, ca 13.5 air mi SW of Winter Park.
Along stream and river in spruce/lodgepole pine forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Meadow Creek Road, ca 28 air mi W of Boulder; ca 5.5 air mi N of Fraser.
Open aspen/lodgepole pine forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: S of Lake Granby along Doe Creek, ca 6.5 air mi ENE of Granby; ca 15.5 air mi NNW of Fraser.
Along creek and in open meadow. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Monarch Lake, ca 10.5 air mi E of Granby; ca 12 air mi NE of Fraser.
Lakeside, spruce/lodgepole pine/fir forest, and streamside. Phenology: flowering & fruiting.

U.S.A., Colorado, Boulder County: Roosevelt National Forest: Front Range: Indian Peaks Wilderness: Saint Vrain Mountain Trail, ca 18 air mi NW of Boulder; ca 7 air mi NW of Ward.
Lodgepole pine/spruce forest, subalpine, and streamside. Phenology: flowering & fruiting.

U.S.A., Colorado, Boulder County: Roosevelt National Forest: Front Range: Indian Peaks Wilderness: Rainbow Lakes, ca 3.5-4 air mi NW of Nederland; ca 12.5 air mi NE of Fraser.
Lakeside and moist spruce/lodgepole pine/fir forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Kawuneeche Road, South Supply Creek, ca 3.5 air mi WNW of Grand Lake.
Along creek, wet meadow, and regenerating lodgepole pine forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Indian Peaks Wilderness: Cascade Creek Trail, along Buchanan Creek, ca 1 mi E of Monarch Lake.
Dry slopes. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Byers Peak Wilderness: Lake Evelyn Trail, ca 9.5 air mi WSW of Fraser.
Along trail through mixed coniferous forest with intermittent streams and meadows. Phenology: flowering & fruiting.
with Jill Torres

U.S.A., Colorado, Gilpin County: Arapaho National Forest: Front Range, tributary of North Clear Creek, ca 4 air mi WNW of Central City; ca 6.5 air mi NE of Empire.
Along small stream through spruce forest and cleared meadows. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Williams Fork Mountains: Skylark Creek, ca 1.5 mi W of Mule Creek, ca 13.5 air mi SSW of Hot Sulphur Springs.
Spruce/fir forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Never Summer Wilderness: Cascade Mountain, ca 10.5 air mi N of Granby.
Spruce/lodgepole pine/fir forest and clearings. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Rabbit Ears Range: Buffalo Creek, ca 15.5 air mi NW of Granby; ca 15 air mi NE of Parshall.
In disturbed areas and along small creek tributary. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Williams Fork Mountains: South Fork Williams Fork Trail, ca 24 air mi SSE of Hot Sulphur Springs; ca 9.5 air mi NW of Loveland Pass.
Along river and adjacent spruce/fir forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Rabbit Ears Range: North Fork Cabin Creek along Cabin Creek Road, ca 3 mi W of Colo Hwy 125, ca 9 air mi N of Hot Sulphur Springs.
Along creek and roadside. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Rabbit Ears Range: 0.5 mi S of Willow Creek Pass along Pass Creek, ca 28.5 air mi SE of Walden.
Along creek and in adjacent meadow and lodgepole pine forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Front Range: Arapaho Bay of Lake Granby, along Roaring Fork Creek, ca 9 air mi SE of Grand Lake.
Roadside and lakeside. Phenology: flowering & fruiting.
with Michael Foley

U.S.A., Colorado, Grand County: Rabbit Ears Range: Black Mountain, ca 6 air mi NW of Parshall and ca 10.5 air mi NE of Kremmling.
Mountain slope. Phenology: flowering & fruiting.
with Ronald L. Hartman

U.S.A., Colorado, Grand County: Rabbit Ears Range: Lindsey Creek to Grannys Nightcap, ca 18.5 air mi NNW of Kremmling and ca 23 air mi SE of Steamboat Springs.
Along creek. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Vasquez Peak Wilderness: Vasquez Mountains: unnamed stream and junction with Vasquez Creek, ca 5 air mi SW of Winter Park and ca 7.5 air mi SSW of Fraser.
Along stream. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Gore Range: off BLM Road 2750 near Dice Hill and Sheephorn Mountain, ca 5.5 air mi E of Radium and ca 9.5 air mi NW of Heeney.
Mixed conifer stand. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Indian Peaks Wilderness: Front Range: Buchanan Creek, ca 15 air mi ENE of Granby and ca 9 air mi WNW of Ward.
Along Creek Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Middle Park: just S of Hot Sulphur Springs State Wildlife Area and just N of Little Muddy, ca 3.5 air mi SSW of Hot Sulphur Springs and 11 air mi SW of Granby.
Moist aspen grove. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Rabbit Ears Range: tributary of Willow Creek, ca 9.5 air mi NW of Granby and ca 9.5 air mi SE of Willow Creek Pass.
Moist disturbed area. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Recreation Area: Willow Creek Reservoir, ca 4 air mi NW of Granby and ca 11 air mi SW of Grand Lake.
Moist aspen stand. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Middle Park: Parshall Divide, ca 1.5 air mi WSW of Hot Sulphur Springs and ca 2.5 air mi ENE of Parshall.
Roadside through Douglas fir. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Arapaho National Forest: Middle Park: just S of U.S. Hwy 40, ca 4 air mi WNW of Granby and ca 5.5 air mi NE of Hot Sulphur Springs.
Lodgepole pine slope. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Middle Park: Round Creek, ca 11.5 air mi NE of Kremmling and ca 13.8 air mi NW of Hot Sulphur Springs.
Disturbed sagebrush meadow. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Gore Range: Inspiration Point, ca 6.5 air mi SW of Kremmling and ca 5.5 air mi NE of Radium.
Disturbed area through mixed coniferous woodland. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Rabbit Ears Range: Troublesome Wilderness: Rabbit Ears Creek, ca 12.5 air mi SW of Rand and ca 17.5 air mi NE of Kremmling.
Disturbed opening adjacent to spruce stand. Phenology: flowering & fruiting.

U.S.A., Colorado, Lake County: Central Colorado: Sawatch Range, East Slope Continental Divide: off Forest Road 109, ca 2.5 air mi N of Leadville.
Mixed forest (Pinus contorta and Picea engelmannii). Phenology: flowering & fruiting.
Accession: (unaccessioned)

U.S.A., Colorado, Eagle County: Central Colorado: Sawatch Range, West Slope Continental Divide: below Mount Jackson, along Lake Creek Forest Service Trail 1880, ca 11 air mi S of Edwards.
Open spruce-fir forest and boulder field. Phenology: flowering & fruiting.
with Brain Elliott
Accession: (unaccessioned)

U.S.A., Colorado, Eagle County: Central Colorado: Sawatch Range, West Slope Continental Divide: along East Lake Creek, ca 8 air mi SSW of Avon.
Spruce-fir forest. Phenology: flowering & fruiting.
with Brian Elliott
Accession: (unaccessioned)

U.S.A., Colorado, Eagle County: Central Colorado: Sawatch Range, West Slope Continental Divide: along East Lake Creek Trail 1880, ca 5 air mi S of Edwards.
Aspen woodland. Phenology: flowering & fruiting.
with Brian Elliott

U.S.A., Colorado, Eagle County: Central Colorado: Sawatch Range, West Slope Continental Divide: along Reudi Trail at west end of reservoir, to second powerline crossing from trailhead, ca 11.5 air mi E of Basalt.
Dense aspen woodland with interspersed lodgepole. Phenology: flowering.

U.S.A., Colorado, Eagle County: Central Colorado: Gore Range, West Slope Continental Divide: along Gore Creek Trail 2015, from Wilderness sign E ca 2.5 mi, ca 7 air mi E of Vail.
Mixed forest with aspen, lodgepole, spruce-fir and Douglas Fir. Phenology: flowering & fruiting.

U.S.A., Colorado, Routt County: Sierra Madre\Park Range: Park Range: Routt National Forest: ca 2 air mi SSE of Lynx Pass on Morrison Creek Road, ca 13 air mi ESE of Yampa; ca 29 air mi SSE of Steamboat Springs.
Moist swale in lodgepole pine-aspen forest.
2. Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil
Annotated by David J. Keil in 2003. approaching var. clavatum-Keil
with Steven Nelson

U.S.A., Colorado, Routt County: Sierra Madre\Park Range: Park Range: Routt National Forest: Lone Spring Butte, ca 5.5 air mi ESE of Yampa, ca 24 air mi SSE of Steamboat Springs.
In opening in mostly subalpine fir forest.
2. Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil
Annotated by David J. Keil in 2003. approaching var. clavatum-Keil
with Steven Nelson

U.S.A., Colorado, Routt County: Sierra Madre\Park Range: Park Range: Routt National Forest: N of head of Newcomer Creek, ca 7 air mi SE of Yampa, ca 27 air mi S of Steamboat Springs.
Aspen grove.
Annotated by David J. Keil in 2003. approaching var. clavatum
with Steven Nelson

U.S.A., Colorado, Routt County: Sierra Madre\Park Range: Park Range: Routt National Forest: Along Service Creek ca 3 air mi above the Yampa River, ca 15 air mi SSE of Steamboat Springs.
Aspen forest bracken understory. Approaching var. clavatum Phenology: flowering & fruiting.
Annotated by David J. Keil in 2003. approaching var. clavatum-Keil

U.S.A., Colorado, Routt County: [location and coordinates withheld]
Aspen-oak woods.
with Michelle Nelson

U.S.A., Colorado, Routt County: Sierra Madre\Park Range: Park Range: Routt National Forest: Above Volcano Siding ca 2 air mi SW of Long Park, ca 13.5 air mi SE of Yampa, ca 33 air mi S of Steamboat Springs.
Brushy aspen woods.
with Michelle Nelson

U.S.A., Colorado, Jackson County: Sierra Madre\Park Range: Park Range: ca 2 air mi N of Red Elephant Mountain.
Dry open areas under lodgepole pine and spruce. Approaching var. clavatum Phenology: flowering & fruiting.

U.S.A., Colorado, Jackson County: Sierra Madre\Park Range: Park Range: ca 6.5 air mi SSE of Mount Ethel.
T17N R82W S20; also S21
Aspen forests.
with Sunny and Joel Kastning

U.S.A., Colorado, Jackson County: Sierra Madre\Park Range: Park Range: ca 20 air mi WSW of Walden in the Rainbow Lake area.
Lodgepole pine-aspen mixed area.
Annotated by David J. Keil in 2003.

U.S.A., Colorado, Routt County: Sierra Madre\Park Range: Park Range: vicinity of Mad Creek Trail, ca 7 air mi NNW of Steamboat Springs.
Edge of creek.

U.S.A., Colorado, Routt County: [location and coordinates withheld]
Spruce-fir-Pseudotsuga forest and adjacent meadows.
Annotated by David J. Keil in 2003.

U.S.A., Colorado, Grand County: [location and coordinates withheld]
Meadows and disturbed areas.

U.S.A., Colorado, Jackson County: Sierra Madre\Park Range: Park Range: near junction of Forest Roads 600 and 689, ca 0.5 mi N of Big Creek Lake, ca 22 air mi NW of Walden; along South Fork Big Creek.
Forest near creek.
Annotated by David J. Keil in 2003.

U.S.A., Colorado, Jackson County: Sierra Madre\Park Range: Park Range: along Forest Road 600, ca 25 air mi NW of Walden.
Roadside.

U.S.A., Wyoming, Carbon County: Sierra Madre/Park Range: Sierra Madre: along tributary of North Fork Big Creek SSE of Bear Mountain, ca 13.5 air mi SE of Encampment.
Stony sagebrush slope in lodgepole pine forest. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Sierra Madre/Park Range: Sierra Madre: ca 9 mi NNW of Blackhall Mountain, along the Encampment River.
Fir-pine. Phenology: flowering.
with David Culp
Accession: RM 569628, Barcode: RM0280738

U.S.A., Wyoming, Carbon County: Sierra Madre/Park Range: Sierra Madre: Singer Peak.
Dry open areas in aspen, lodgepole. Phenology: flowering.
Accession: RM 569629, Barcode: RM0280748

U.S.A., Wyoming, Carbon County: Sierra Madre/Park Range: Sierra Madre: ca 8 air mi SSE of Miller Hill.
Ridgesides with sagebrush and mountain mahogany grading to scrub aspen. Phenology: flowering.
with Lee Huston and Sunny Kastning
Accession: RM 569625, Barcode: RM0280732

U.S.A., Wyoming, Carbon County: Sierra Madre/Park Range: Sierra Madre: ca 3 air mi ENE of Battle Mountain, E of Battle Creek.
Sagebrush-grassland slopes east of Battle Creek. Phenology: flowering.
with Lee Huston and Joel Kastning

U.S.A., Wyoming, Carbon County: Sierra Madre/Park Range: Sierra Madre: ca 9 mi SE of Red Mountain.
Old clear cut in lodgepole pine forest, disturbed. Phenology: flowering.
with Lee Huston & Heather Kastning

Cirsium clavatum var. americanum × Cirsium canescens (2000)
Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil × Cirsium canescens Nutt.
U.S.A., Colorado, Larimer County: North-central Colorado: Slough Creek 0.5-1 air mi NW of Hohnholz Lake #3.
Badlands on side of ridge and into stream bottom, seasonal. Phenology: flowering.
with Sarah Nunn

U.S.A., Colorado, San Miguel County: San Miguel and Lower Dolores River Drainages: at seep crossing Last Dollar Road, ca 0.3 mi SW of Whipple Mountain Trailhead.
Hillside. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Upper North Platte and Laramie River Drainages: hillside between Sage Creek and County Road 401, ca 22 air mi S of Rawlins; ca 19 air mi W of Saratoga.
Snow catch on north facing slope; black sandy soil with patches of aspen trees and flowering shrubs. Phenology: flowering & fruiting.

U.S.A., Colorado, Saguache County: Southern Gunnison Basin: San Juan Mountains: ca 4 air mi N of Sawtooth Mountain; ca 9.2 air mi W of Razor Creek Dome; ca 15 air mi S of Gunnison in Soldiers Park.
Aspen grove with occasional fir and pine. Phenology: flowering & fruiting.

U.S.A., Colorado, Dolores County: Upper Dolores River Drainage and Adjacent Areas: San Juan National Forest: Black Mesa, Forest Road 533 and Forest Road 611, ca 27 air mi NNE of Dolores.
Montane meadow with scattered spruce-fir and drainage along road. West to southwest facing. Phenology: flowering & fruiting.

U.S.A., Colorado, Dolores County: Upper Dolores River Drainage and Adjacent Areas: San Juan National Forest: ca 5 air mi NW of Rico along Geyser Creek Trail, Forest Trail 648.
Aspen, spruce, snowberry, larkspur, and riparian area along creek and natural geyser, northwest face. Phenology: flowering.
with Sierra Smith

U.S.A., Colorado, Larimer County: Roosevelt National Forest: Front Range: from Rawah Trailhead on Laramie River Road (County Road 103), west and south facing slopes of Middle Mountain, ca 40 air mi W of Fort Collins.
Aspen groves on upper slopes and the sides of horse trails. Phenology: flowering.

U.S.A., Colorado, Larimer County: Roosevelt National Forest: Medicine Bow Mountains: Forest Road 200, 1 mi S of Boswell Creek Campground, ca 61 air mi NW of Fort Collins.
Limber pine and Artemisia steppe, dry and heavily grazed. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Range: on North Fork Road.
41.374° N, 106.183° W; NAD 83, uncertainty 1 mi., Digital Map
Roadside in lodgepole pine and spruce-fir zone. Flowers white. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Rock Creek Roadless Area, ca 25 air mi NW of Laramie.
Wetlands and marshes; common adjacent to Pinus contorta and Picea engelmannii-Abies lasiocarpa.
Leila Stanfield, 39. 7/27/1991.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Rock Creek Roadless Area, ca 25 air mi NW of Laramie.
Wetlands and marshes; common adjacent to Pinus contorta and Picea engelmannii-Abies lasiocarpa. Phenology: flowering & fruiting.
Leila Stanfield, 40. 7/27/1991.

U.S.A., Wyoming, Albany County: Laramie Range: ridge on divide between Middle Branch Middle Lodgepole Creek and South Lodgepole Creek, ca 1.5 mi N of Wyo Hwy 210 (Happy Jack Road), 1.3 mi SW of Eagle Rock and 9 mi E of Laramie.
Base of Sheman Granite knob on thin, clayey soil with surface of granite pea gravel in opening in Pinus flexilis woods with understory of scattered Purshia tridentata, Senecio fendleri, Leucopoa kingii, and Sedum lanceolatum. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Medicine Bow Mountains: along South Fork Canadian River ca 1/4 - 1/2 mi S of the confluence, ca 6 air mi N of Gould; ca 16 air mi SE of Walden.
Aspen slopes. Phenology: flowering.
Annotated by Ronald L. Hartman.

U.S.A., Colorado, Jackson County: North-central Colorado: Never Summer Mountains: along the Illinois River at the junction of Forest Roads 750 and 765, ca 8.5 air mi S of Gould; ca 26 air mi SE of Walden.
Meadows among aspen groves in the river bottom. Phenology: flowering.
Annotated by Ronald L. Hartman.

U.S.A., Colorado, Moffat County: North-central Colorado: Elkhead Mountains: Sand Point above the head of Fourmile Creek, ca 7.5 air mi E of Fortification; ca 22.5 air mi NNE of Craig.
Open areas in spruce-fir-aspen forest. Phenology: flowering & fruiting.
Annotated by Ronald L. Hartman.

U.S.A., Colorado, Routt County: North-central Colorado: Elkhead Mountains: 4 wheel drive road near Meaden Mountain, 10-12 air mi NW of Clark.
Lodgepole pine and aspen woodlands. Phenology: flowering.

U.S.A., Colorado, Routt County: North-central Colorado: Elkhead Mountains: trail to Sand Mountain, ca 5-8 air mi NW of Clark.
Aspen and conifer forests. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Medicine Bow Mountains: Colorado State Forest: ca 4 air mi NE of Gould.
Logging road bordered by lodgepole pine, aspen, and alder. Phenology: flowering.
with Sarah Nunn

U.S.A., Colorado, Moffat County: North-central Colorado: Elkhead Mountains: trail to Black Mountain, ca 20 air mi NE of Craig.
Spruce-fir forest. Phenology: flowering.
with Sarah Nunn

U.S.A., Colorado, Carbon County: Sierra Madre: Medicine Bow National Forest: Big Creek Park on road from Pearl Colorado, 2.5 road mi from Colorado.
Spruce-fir forest and rocky slopes. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Park Range: N-S trail just off Fryingpan Trail, 4-5 air mi S of Big Creek Lakes, ca 18 air mi NW of Walden.
Forested edge. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Medicine Bow Mountains: Jack Creek and vicinity, 0.5 air mi SW of Calamity Pass, ca 6 air mi S of Gould.
Spruce-fir forest. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Park Range: Rainbow Lake Trail, ca 17 air mi WSW of Walden.
Trail through spruce forest. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Medicine Bow Mountains: Colorado State Forest: from peak "12184" to the south, ca 6.5 air mi NE of Gould.
Alpine rocky slope. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Never Summer Mountains: Colorado State Forest: Upper Michigan Ditch, ca 7-7.5 air mi E of Gould.
Wet areas and along dirt road through spruce-fir. Phenology: flowering & fruiting.

U.S.A., Colorado, Jackson County: North-central Colorado: Park Range: Buffalo Ridge Trail to NE of Davis Peak, ca 25-26 air mi NW of Walden.
Spruce-fir and open drainages. Phenology: flowering & fruiting.

U.S.A., Colorado, Jackson County: North-central Colorado: Park Range: Newcomb Park Trail, 0.5-2.5 trail mi W of trail head (to granitic domes and Newcomb Creek angling NW), ca 20-21 air mi SW of Walden.
Meadows and woodland, pond edges. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Rabbit Ears Range: along Grassy Run or Trail 1135 on the east side of Arapaho Ridge, ca 7.5-8 air mi SW of Rand; ca 23.5 air mi S of Walden.
Open mixed conifer forest. Phenology: flowering.

U.S.A., Colorado, Jackson County: North-central Colorado: Rabbit Ears Range: ca 1 1/4 air mi S of Slack-Weiss Reservoir and ca 2 air mi WNW of the north end of Arapaho Ridge, ca 21.5 air mi S of Walden.
Sagebrush meadows. Phenology: flowering & fruiting.

U.S.A., Colorado, Jackson County: North-central Colorado: North Park: along County Road 5, ca 1/2 - 1 1/4 mi N of Chedsey Creek, ca 7.5-8.5 air mi S of Delaney Butte, ca 17 air mi SW of Walden.
Rolling Artemisia - Eriogonum ridgetop. Phenology: flowering.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: head of Harrison Creek, ca 2 air mi E of Walton Peak, ca 3 air mi SW of Rabbit Ears Pass; ca 13 air mi SE of Steamboat Springs.
Open, stony slope with occassional lodgpole pine on volcanic substrate. Phenology: flowering.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: Sarvis (Sarvice) Creek Wilderness: along Silver Creek, ca 1.5 air mi S of Gore Mountain, ca 13.5-15 air mi ENE of Yampa.
Meadows between the willow carr and mixed conifer forest. Phenology: flowering.

U.S.A., Colorado, Grand County: North-central Colorado: Park Range: along Silver Creek Trail, ca 2-3 air mi SE of Gore Mountain, ca 15-16.5 air mi NW of Kremmling.
Along logging road in old timber sale with mixed conifer regrowth. Phenology: flowering & fruiting.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: Hinman Lake and vicinity to Hinman Creek, ca 1.5 air mi N of the Elk River, ca 6.5 air mi NE of Clark; ca 20 air mi N of Steamboat Springs.
Aspen woodlands. Phenology: flowering.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: along Middle Fork Little Snake River just N of Crane Park, ca 6.5 air mi NNE of Columbine; ca 32 air mi N of Steamboat Springs.
Open mixed conifer forest above the river. Phenology: flowering & fruiting.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: along Trail 1204 along Middle Fork Little Snake River between Big Red Park and the Continental Divide, ca 29.5 air mi N of Steamboat Springs.
Aspen forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: northern part of Green Ridge on Forest Road 285, ca 7-7.5 air mi SE of Oak Creek; ca 4.5 air mi NE of Yampa.
Aspen forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: on the east side of Green Ridge just N of Muddy Slide (The Slide), ca 6-6.5 air mi E of Yampa; ca 9.5-10 air mi SE of Phippsburg.
Open slopes and draw on Mancos shale. Phenology: flowering.

U.S.A., Colorado, Routt County: North-central Colorado: Park Range: along Horse Creek to Rock Creek and the ridge to the north, ca 1.5-2 air mi E of Long Park, ca 15.5-16 air mi SE of Yampa.
Meadow and open grassy lodgepole pine forest on ridgetop. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: North-central Colorado: Park Range: along old logging road between Jolley and Horse creeks, ca 4 air mi WSW of Gore Pass, ca 12.5 air mi W of Kremmling.
Open aspen forest. Phenology: flowering.

U.S.A., Colorado, Routt County: North-central Colorado: Elkhead Mountains: along South Fork Slater Creek, ca 1 1/4-1 3/4 air mi N of Lost Park, ca 22-22.5 air mi N of Hayden.
Aspen forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Moffat County: North-central Colorado: Elkhead Mountains: at the end of Forest Road 133, ca 3 air mi NE of Black Mountain, ca 2.5 air mi SE of Buck Point, ca 23.5 air mi NNE of Craig.
Small clearing in aspen-spruce-fir forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Jackson County: North-central Colorado: Rabbit Ears Range: along the Continental Divide ca 0.5-1 air mi NW of Chimney Rock, ca 8 air mi ESE of Muddy Pass; ca 27.5 air mi SSW of Walden.
Old logged area in mixed conifer-aspen forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Jackson County: North-central Colorado: Rabbit Ears Range: along East Fork Arapaho Creek, ca 1.5-2 air mi W of Arapaho Ridge, ca 9 air mi SW of Rand; ca 24 air mi S of Walden.
Old clearcut with open lodgepole pine regeneration. Phenology: flowering & fruiting.

U.S.A., Colorado, Moffat County: North-central Colorado: Wymore Gulch, ca 7 air mi NE of Craig.
Sagebrush slopes. Phenology: flowering.
Annotated by B. E. Nelson.

U.S.A., Colorado, Jackson County: North-central Colorado: Never Summer Mountains: Never Summer Wilderness: between end of 4-wheel drive trail and start of wilderness or 1-2 air mi ESE of start of jeep trail.
Coniferous forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Jackson County: North-central Colorado: Owl Mountain near junction of Forest roads 771 and 792.
Lodgepole pine. Phenology: flowering & fruiting.
Annotated by B. E. Nelson.

U.S.A., Colorado, Jackson County: North-central Colorado: Medicine Bow Mountains: Forest Road 204, 0.7 road mi SE of Forest Service boundary, ca 1 air mi from Kings Canyon.
Phenology: flowering & fruiting.
Annotated by B. E. Nelson.

U.S.A., Colorado, Jackson County: North-central Colorado: Medicine Bow Mountains: Colorado State Forest State Park: along County Road 8A.
Aspen grove and stream bottom. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Laramie Range: along Bear Creek, ca 33 air mi SW of Douglas.
Rock outcrops. Phenology: flowering & fruiting.
with J. Brondum and T. McGowan

U.S.A., Wyoming, Natrona County: [location and coordinates withheld]
Steep gravelly slope with rock outcrops, "pavement", grassy patches, and scattered limber pine. Phenology: flowering & fruiting.
Annotated by B. A. Packer.

U.S.A., Colorado, Boulder County: Left-hand Creek near Puzzler, near Ward.
Phenology: fruiting.

U.S.A., Colorado, Eagle County: Minturn.
Phenology: fruiting.
2. Cirsium scariosum Nutt.

U.S.A., Colorado, Larimer County: Estes Park.
Phenology: fruiting.

U.S.A., Colorado, Larimer County: Mountains.
Phenology: flowering & fruiting.
George E. Osterhout, 7622. 8//1894.

U.S.A., Colorado, Grand County: Arapaho National Forest, Continental Divide Trail W of Willow Creek Pass.
Dry lodgepole forest, disturbed roadside; with Vaccinium Lupinus caudatus, Anaphalis margaritacea and Arnica. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Gore Pass: W side.
Stream bank, with Geranium richardsonii and Senecio triangularis. Phenology: fruiting.

U.S.A., Wyoming, Converse County: Laramie Range: along Rabbit Creek, ca 20 air mi SW of Douglas.
Along creek and adjacent granite outcroppings. Phenology: flowering & fruiting.
with T. McGowan

U.S.A., Wyoming, Albany County: Laramie Range: along Soldier Creek, ca 37 air mi S of Douglas.
In granite outcroppings. Phenology: flowering & fruiting.
with T. McGowan & J. Brondum

U.S.A., Colorado, Rio Blanco County: Flat Tops/White River Plateau: Flat Tops Wilderness: Mirror Lake Trail, ca 30 air mi E of Meeker; ca 6 air mi NW of Trappers Lake.
Northeast-facing forested slopes, with Engelmann spruce, subalpine fir, lodgepole pine, and aspen.
James P. Vanderhorst, 1104. 7/15/1990.

U.S.A., Colorado, Garfield County: Flat Tops/White River Plateau: Broken Rib Spring, ca 9 air mi NE of Glenwood Springs.
Wet area around spring, with Picea, Abies, and Salix.
James P. Vanderhorst, 1292. 7/23/1990.

U.S.A., Colorado, Garfield County: Flat Tops/White River Plateau: Flat Tops Wilderness: vicinity of McMillan Lake, ca 30 air mi NNE of Glenwood Springs.
Area of old forest fire with northeast exposure.
James P. Vanderhorst, 1392. 7/28/1990.

U.S.A., Colorado, Rio Blanco County: Flat Tops/White River Plateau: Flat Tops Wilderness: Marvine Lakes, ca 29 air mi ESE of Meeker.
Spruce-fir woods.

U.S.A., Colorado, Routt County: [location and coordinates withheld]
Cow pasture about 1/4 mi from old homestead, meadows, and aspen woods.
with Carlos Palaci

U.S.A., Colorado, Eagle County: Flat Tops/White River Plateau: Deer Creek, ca 6 air mi W of Burns.
Old burned forest with reproducing aspen.

U.S.A., Colorado, Garfield County: Flat Tops/White River Plateau: Lower Short Creek, ca 14 air mi NE of Glenwood Springs.
Meadows on hills above creek, with Festuca thurberi, snowberry, and sagebrush.

U.S.A., Colorado, Garfield County: Flat Tops/White River Plateau: Butler Creek, ca 18 air mi NW of Glenwood Springs.
Meadows and aspen woods with snowberry.
James P. Vanderhorst, 3618a. 7/25/1991.

U.S.A., Colorado, Rio Blanco County: Flat Tops/White River Plateau: Dunckley Flat Tops N of Dunckley Pass, ca 11 air mi WSW of Oak Creek.
Meadow dominated by Veratrum.

U.S.A., Colorado, Rio Blanco County: Flat Tops/White River Plateau: Cyclone Creek, ca 19 air mi WSW of Oak Creek.
Meadow above creek, with Veratrum, Dugaldia, and Rudbeckias.

U.S.A., Colorado, Garfield County: Flat Tops/White River Plateau: South Fork White River, "Budges Resort", ca 20 air mi N of Glenwood Springs.
Meadows with grasses and forbs.

U.S.A., Colorado, Garfield County: Flat Tops/White River Plateau: limestone ridge above Bison Lake, ca 13 air mi N of Glenwood Springs.
Exposed limestone with pockets of poorly drained soil, northern exposure, with scattered spruce.

U.S.A., Colorado, Rio Blanco County: Flat Tops/White River Plateau: Sleepy Cat Peak, ca 23 air mi ENE of Meeker.
South-facing meadows on Mancos shale substrate.

U.S.A., Colorado, Rio Blanco County: Flat Tops/White River Plateau: Sleepy Cat Trail, ca 16 air mi ENE of Meeker.
Aspen woodland.

U.S.A., Wyoming, Albany County: Laramie Range: Medicine Bow National Forest: ca 5 air mi SE of Laramie.
In forested grassland on southwest facing slope. Phenology: flowering & fruiting.
with T. McGowan

U.S.A., Wyoming, Carbon County: South-central Wyoming: Muddy Mountain, ca 8 air mi NE of Baggs; ca 47 air mi SSW of Rawlins.
Meadow areas above the mountain shrub-aspen thickets. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: along the Continental Divide off Sage Creek or County Road 401, ca 26 air mi S of Rawlins.
Mountain shrub and aspen thickets on lee slopes. Phenology: flowering.
Annotated by Beth Ward.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: along the Continental Divide off Sage Creek or County Road 401, ca 26 air mi S of Rawlins.
Sandy cut bank in sagebrush grassland. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: Hell Canyon off Green Ridge, ca 1 air mi E of Savery Creek, ca 41 air mi S of Rawlins; ca 20 air mi NE of Baggs; ca 3.5 air mi SW of Tullis.
Aspen woods. Phenology: flowering.
with Beth Ward

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: Hell Canyon off Green Ridge, ca 1 air mi E of Savery Creek, ca 41 air mi S of Rawlins; ca 20 air mi NE of Baggs; ca 3.5 air mi SW of Tullis.
Mountain shrub community adjacent to aspen woods. Phenology: flowering & fruiting.
Annotated by Beth Ward.
with Beth Ward

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: along a small drainage on the south side of Browns Hill or County Road 602, ca 3/4 mi E of Tullis, ca 37.5 air mi S of Rawlins; ca 23 air mi NE of Baggs.
Sagebrush-bitterbrush-grassland slopes and ridgetop. Phenology: flowering.

U.S.A., Wyoming, Sweetwater County: [location and coordinates withheld]
Meadows below the springs. Phenology: flowering.
Annotated by Beth Ward.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: along the Continental Divide on Miller Hill off Miller Hill or County Road 505, ca 18.5 air mi S of Rawlins; ca 6.5 air mi ESE of Bridger Pass.
Aspen woods. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: near the head of Littlefield Creek drainage, ca 26 air mi S of Rawlins; ca 29 air mi NE of Baggs.
T17N R89W S25 South1/4; also N1/4 S36
Aspen-willow woods or aspen woods. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: on the divide between Wild Cow and Little Savery drainages, ca 2.5-3 air mi N of Ketchum Buttes, ca 32 air mi SSW of Rawlins; ca 22.5 air mi NE of Baggs.
Aspen woods. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: along Dirtyman Fork and area to the south, 0.8-1.5 air mi SW of Dexter Peak, ca 5-5.5 air mi E of Tullis; ca 36 air mi S of Rawlins; ca 26.5 air mi NE of Baggs.
Open aspen forest. Phenology: flowering.

U.S.A., Wyoming, Sweetwater County: South-central Wyoming: Rock Springs Uplift: northern slopes and top at north end of Essex Mountain, ca 32 air mi NNE of Rock Springs.
T24N R103W S8 SW1/4; also SE1/4 S7 and NE1/4 S18
Moist area. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: top and south slopes of Battle Mountain, ca 8 air mi E of confluence of Savery Creek and Little Snake River; ca 18.5 air mi E of Baggs.
T12N R88W S10 W1/2; also SE1/4 S9 and NE1/4 S16
Top of mountain. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: on east side of Atlantic Rim, ca 2 air mi SW of Bridger Pass; ca 20.5 air mi SSW of Rawlins.
Hillside above spring. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: top and north slopes of Cow Creek Butte, ca 1 mi NW of Deep Gulch; ca 32 air mi SSW of Rawlins.
Open hillside. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: north facing slopes and bottom of Garden Gulch, ca 1.5 air mi SW of Cow Creek Butte; ca 33 air mi SSW of Rawlins.
Moist draw. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: below Rendle Rim, ca 1 air mi SSW of Rendle Butte; ca 30.5 air mi SSW of Rawlins.
Moist draw. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: near headwaters of Wild Cow Creek, ca 3 air mi SW of Rendle Butte; ca 33 air mi SSW of Rawlins.
Shaded hillside. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: northwest slopes of Battle Mountain, ca 3 air mi N of Colorado; ca 18 air mi E of Baggs.
Shaded aspen grove. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Sierra Madre: top and northeast slopes of Battle Mountain, ca 19 air mi E of Baggs.
T12N R88W S3; also NW1/4 S2 and T13N R88W S35
Shaded draw. Phenology: flowering.

U.S.A., Wyoming, Carbon County: South-central Wyoming: Deep Creek Rim and draws on west-facing slope, ca 3 air mi E of Wyo Hwy 789; ca 8.5 air mi NNE of Baggs.
T14N R91W S26
Rocky draw, sandy soil. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Sierra Madre: Miller Creek, ca 10 air mi S of Encampment.
T13N R84W S27
Moist open woods near creek. Occasional; flowers white. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Red Mountain and vicinity: ridge ca 1 air mi E of Red Mountain summit, ca 27 air mi SW of Laramie.
Lee slope in mountain shrub community. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: 4.5 mi from the river on the North Platte River Access Road.
Frequent in gravelly soil at the edge of the road. Phenology: flowering & fruiting.
with Linda Nelson

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: ENE of Little Brooklyn Lake, behind Open Air Chapel, above road.
Moist southeast-facing slope.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: E of Brooklyn Lake, near plot 214.
Edge of spruce-fir forest, near moist forb meadow.
with Tom Fletchall

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: SE of Brooklyn Lake, drainage above road just N of southern boundary of extended GLEES study area.
Forb meadow in moist drainage.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Kennaday Peak, ca 15 air mi E of Saratoga.
T17N R81W S8; also S16 and S17
Grassy and rocky slopes and ridges above treeline. Phenology: flowering.

U.S.A., Colorado, Larimer County: Chambers Lake.

U.S.A., Colorado, Larimer County: Thompson Canyon.
Phenology: fertile.

U.S.A., Colorado, Larimer County: Little South: Rockwell's Place.
Phenology: fertile.

U.S.A., Colorado, Larimer County: Chambers Lake.
Phenology: fertile.
George E. Osterhout, 6335. 8/6/1924.

U.S.A., Colorado, Larimer County: Estes Park.

U.S.A., Colorado, Larimer County: E of Estes Park along the Thompson.

U.S.A., Colorado, Jackson County: North Park.
Phenology: flowering.

U.S.A., Colorado, Larimer County: Thompson Canyon above the Forks.

U.S.A., Colorado, Larimer County: Glacier Park on the South Fork Thompson.

U.S.A., Colorado, Larimer County: Thompson Canyon above the Forks.
Possible hybrid with C. undulatum; narrow phyllary glands present. Phenology: fertile.

U.S.A., Colorado, Eagle County: Red Cliff.
George E. Osterhout, 3362x. 8/16/1906.

U.S.A., Colorado, Eagle County: Red Cliff.
George E. Osterhout, 3389a. 8/17/1906.

U.S.A., Colorado, Larimer County: Estes Park: Park Hill.

U.S.A., Colorado, Larimer County: Little South: Rockwell's Place.

U.S.A., Colorado, Grand County: Sulphur Springs.
George E. Osterhout, 3566. 8/7/1907.

U.S.A., Colorado, Larimer County: Cameron Pass.
George E. Osterhout, 5006. 8/2/1913.

U.S.A., Colorado, Gilpin County: Toland.

U.S.A., Colorado, Larimer County: Cameron Pass.

U.S.A., Colorado, Grand County: Sulphur Springs.
George E. Osterhout, 3589a. 8/8/1907.

U.S.A., Colorado, Grand County: Sulphur Springs.

U.S.A., Colorado, Routt County: Steamboat Springs.

U.S.A., Colorado, Larimer County: Home Post Office.
T9N R74W S33

U.S.A., Colorado, Jackson County: North Park: Michigan River.

U.S.A., Colorado, Larimer County: Stove Prairie, Bosworth's Ranch.

U.S.A., Colorado, Jackson County: Hills E of North Park.

U.S.A., Colorado, Boulder County: Ward.

U.S.A., Colorado, Routt County: N of Bear [Yampa] River, E of Hayden.

U.S.A., Colorado, Larimer County: Thompson Canyon.
Accession: USFS 312751

U.S.A., Colorado, Larimer County: Bosworth's Ranch.

U.S.A., Colorado, Larimer County: Vicinity of Stove Prairie.

U.S.A., Colorado, Larimer County: Bosworth's Ranch, Stove Prairie.

U.S.A., Colorado, Larimer County: Thompson Canyon.

U.S.A., Colorado, Larimer County: Along trail to Longs Peak.

U.S.A., Colorado, Larimer County: Longs Peak Inn, trail to Storm Pass.
Seemingly abnormal heads, perhaps a peculiar form of C. o(s?)pathulatus, but having some resemblance to C. modestus. Phenology: flowering & fruiting.

U.S.A., Colorado, Routt County: Hayden.

U.S.A., Colorado, Eagle County: Minturn.

U.S.A., Colorado, Grand County: Near Tabernash, on U.S. Hwy 40.
Open Pinus contorta forest. Common. Corollas white. Phenology: flowering & fruiting.
with Marjorie W. Porter

U.S.A., Colorado, Jackson County: 3 mi W of Cameron Pass at The Crags Campground.
Open pine forest. Phenology: flowering & fruiting.
with Marjorie W. Porter

U.S.A., Colorado, Jackson County: Routt National Forest: Chedsey Creek, experimental plot 6.
Slope level; gravelly loam soil; park habitat. Quite common. Phenology: flowering & fruiting.
Charles A. Kutzleb, K-39. 7/5/1927.
Accession: USFS 476101

U.S.A., Colorado, Larimer County: Roosevelt National Forest: junction Fish Creek and Little South Poudre River.
Slope 5% east; soil deep gravelly silt; aspen habitat. Occasional. Phenology: flowering & fruiting.
Accession: USFS 475996

U.S.A., Colorado, Grand County: Fraser Experimental Forest: Fool Creek watershed near road 2, 6.5 mi SW of Fraser.
Dry. Phenology: flowering.

U.S.A., Colorado, Larimer County: Canyon of the Thompson River, above the forks.
Collection cited by Rydberg (1910, Bull. Torrey Bot. Club 37: 545) as Carduus americanus x C. laterifolius, and by Petrak (1917, Bieh. Bot. Centralbl. 35: 562) as Cirsium americanum x C. laterifolium with the combination C. xcanalense as a synonym. The name C. xcanalense was not validly published. The name Carduus canalensis, sp. nov., in Osterhout's hand is an unpublished herbarium name. I do not consider this plant to be a hybrid. Keil. Phenology: flowering & fruiting.

U.S.A., Colorado, Boulder County: Left-hand Creek near Puzzler, near Ward.
Brookside trail. Phenology: flowering.

U.S.A., Colorado, Gilpin County: Dark Canyon, above Baltimore.
Brookside trail. Phenology: flowering & fruiting.
Annotated by David J. Keil in 2003. approaching var. osterhoutii.
Edmund R. Cross, s.n.. 8/2/1913.

U.S.A., Colorado, Gilpin County: Dark Canyon, above Baltimore.
Brookside trail. Phenology: flowering & fruiting.
Edmund R. Cross, s.n.. 8/2/1913.

U.S.A., Colorado, Boulder County: Estes Park Road, near Ward.
Dry roadsides. Phenology: flowering & fruiting.
Edmund R. Cross, s.n.. 9/1/1913.

U.S.A., Colorado, Boulder County: Eldora.
39.9488° N, 105.5726° W; NAD 83, uncertainty 1 mi., Nat. Geog. TOPO!

U.S.A., Colorado, Boulder County: Sugar Loaf Mountain.

U.S.A., Colorado, Boulder County:

U.S.A., Colorado, Boulder County: Near Ward.
with G. S. Dodds and W. W. Robbins

U.S.A., Colorado, Gilpin County: Small lake 1/4 mi below Tolland.
Shrub zone. Phenology: flowering & fruiting.
with W. W. Robbins

U.S.A., Colorado, Grand County: Middle Park: near Hot Sulphur Springs.
40.0731° N, 106.102° W; NAD 83, uncertainty 0.5 mi., Nat. Geog. TOPO!
with W. W. Robbins

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: E of Brooklyn Lake, near plot 214.
Spruce-fir forest; near moist forb meadow. Phenology: flowering & fruiting.
with Tom Fletchall

U.S.A., Wyoming, Carbon County: Wyo Hwy 130, ca 3 mi W of Ryan Park, E of North Brush Creek bridge.
Moist roadside ditch.la Phenology: flowering & fruiting.

U.S.A., Wyoming, Converse County: 8 mi SW of Esterbrook, on road to Ft. Fetterman Road.
Along roadside. Chemical voucher. Phenology: flowering & fruiting.
Annotated by David J. Keil in 2003. approaching C. clavatum var. americanum

U.S.A., Wyoming, Albany County: Lake Owen, 11 mi N of Foxpark.
Along dry roadside. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Wyo Hwy 130, ca 3 mi W of Centennial, just across Libby Creek bridge, along Forest Road.
100 ft off road. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: County Road 17, ca 1 mi SE of quarry, then ca 4 mi SE on two-rut road.
With aspen and other broad-leaved trees. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Douglas Creek.
Rocky slope with Pseudotsuga and Juniperus. Corolla white. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Sierra Madre.
Oak-aspen with Wyethia and Lathyrus. Corolla white. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Laramie Range: Headquarters Trail at The Summit rest area of I-80, ca 6 air mi SE of Laramie.
T15N R72W S26 NW1/4; also SE1/4
Aspen-mountain big sagebrush grassland on calcareous soils; with Artemisia tripartita, Festuca idahoensis, Eriogonum umbellatum. cpDNA voucher specimen. Phenology: flowering & fruiting.
with Jane Struttmann

U.S.A., Wyoming, Albany County: Sheep Mountain: near Halls Creek.
Douglas fir clearing. Phenology: flowering & fruiting.
Accession: USFS 402538, Barcode: USFS0071466

U.S.A., Wyoming, Carbon County: Sierra Madre: North Fork Encampment River, ca 7.5 air mi SW of Encampment.
Occasional in moist woods and clearings. flowers pale pink-purple. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Sierra Madre: North Fork Encampment River, ca 3 air mi SW of Encampment.
Few plants in dry open basin. Flowers whitish. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Battle Mountain, south face of mountain, Mexican Ridge, 9 air mi E Savery.
Populus tremuloides overstory. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Tie City.
Moist woods. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Cummins.

U.S.A., Wyoming, Albany County: Telephone Mines.
Alpine parks. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Bridger Peak.
41.1865° N, 107.0317° W; NAD 83, uncertainty 0.5 mi., Digital Map
Open flats. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Laramie.
Pine woods. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Laramie.

U.S.A., Wyoming, Albany County: Laramie

U.S.A., Colorado, Jackson County: SE of Steamboat Springs at junction of U.S. Hwy 40 and Colo Hwy 14 to Walden.
Roadside, ashy soil. Phenology: flowering & fruiting.
with E. Lee

U.S.A., Colorado, Larimer County: Estes Park, Lambs Ranch.
Harry Hapeman, s. n.. 8/26/1896.

U.S.A., Colorado, Rio Blanco County: Between Buford and Trappers Lake.
Elev. 2550 m.
Heads small; phyllaries with glutinous spot, inner one fimbriate; leaves little decurrent, white beneath; inflorescence openly branched; flowers white. Phenology: flowering & fruiting.

U.S.A., Colorado, San Juan County: U.S. Hwy 550 to Silverton, just N of La Plata county.
In opening in aspen forest. Plants perennial, reproducing by root sprouts; flowers very pale yellow; leaves not decurrent. Phenology: fertile.
with Yu-tseng Hsi

U.S.A., Colorado, Larimer County: Cameron Pass.
Harry Hapeman, s. n.. 8/23/1936.

U.S.A., Colorado, Larimer County: Pingree Park Road.
Harry Hapeman, s. n.. 8/29/1936.

U.S.A., Colorado, Montrose County: 20 mi W of Montrose.
Dry hills. Phenology: flowering & fruiting.

U.S.A., Colorado, Larimer County: Mountains.

U.S.A., Colorado, Larimer County: Bosworth's

U.S.A., Colorado, Larimer County: Along Colo Hwy 7, 7.6 mi from junction with Colo Hwy 36.
Moist meadow. Phenology: flowering & fruiting.
with Jane P. Nelson

U.S.A., Colorado, Larimer County: Along Colo Hwy 36, 5 mi from Estes Park.
Juniper-pine woodland. Phenology: flowering & fruiting.
with Jane P. Nelson

U.S.A., Colorado, Larimer County: Along Colo Hwy 36, 5 mi E of Estes Park.
Juniper pine woodland. Phenology: flowering & fruiting.
with Jane P. Nelson

U.S.A., Colorado, Boulder County: Lake Eldora.
Hill sides. Phenology: flowering & fruiting.

U.S.A., Colorado, Boulder County: Ward.
Elev. 2650 m.
Open woods. Phenology: flowering & fruiting.
with H. M. Schmoll

U.S.A., Colorado, Boulder County: Lake Eldora.
Hillsides. Phenology: flowering & fruiting.

U.S.A., Colorado, Boulder County: Near Boulder.
Plains and foothills. Phenology: flowering & fruiting.

U.S.A., Colorado, Boulder County: Mountains between Sunshine and Ward.

U.S.A., Colorado, Montrose County: Uncompahgre Plateau: 1 mi W of Windy Point.
T49N R15W
Rocky talus. Phenology: flowering & fruiting.

U.S.A., Colorado, Boulder County: Middle Saint Vrain Canyon.
Henrietta L. Zobel, s. n.. 7/12/1939.

U.S.A., Wyoming, Carbon County: Rock Creek burn west.
1955 burn. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Stratton Hydrology Study Area: Sane Creek.
Sagebrush rangeland. Phenology: flowering & fruiting.
Max H. Schroeder, s.n.. 7/31/1973.
with Gary L. Ranck

Cirsium clavatum var. americanum ()
U.S.A., Wyoming, Carbon County: Stratton Hydrology Study Area.
Sagebrush rangeland. Phenology: flowering & fruiting.
Max H. Schroeder, s.n.. //.
with Gary L. Ranck

Cirsium clavatum var. americanum ()
U.S.A., Wyoming, Carbon County: Stratton Hydrology Study Area.
Sagebrush rangeland. Phenology: flowering.
Max H. Schroeder, s.n.. //.
with Gary L. Ranck

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: ridge between Eagle and Beaver creeks above the Laramie River, ca 6 air mi SSW of Woods Landing; ca 31 air mi SW of Laramie.
Sagebrush meadow with scattered limber pine. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: ca 0.8 air mi N of Colorado and ca 1 air mi E of North Platte River, ca 40 air mi SE of Saratoga.
Scrub aspen with sagebrush, bitterbrush, and scattered lodgepole pine. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Platte River Wilderness: along Trail 506 and Douglas Creek, 1 air mi E of Pike Pole Campground, ca 44 air mi SW of Laramie; ca 29 air mi SE of Saratoga.
Mixed spruce-fir forest along creek. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Sixmile Creek and Lost Park area, ca 3 air mi SW of Pelton Creek Campground, ca 40 air mi SW of Laramie; ca 36 sir mi SE of Saratoga.
Lodgepole pine forest. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Clark Park, SE of intersection of Forest Road 101 (Sand Lake Road) and Forest Road 323, ca 7 air mi NNW of Centennial.
Park. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: North French Creek at intersection of Forest Road 227 (North French Creek Road) and Forest Road 225 (South French Creek Road), ca 20 air mi SE of Saratoga.
Wet meadow. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Barrett Creek, along Forest Road 225 (South French Creek Road), ca 3 air mi S of Wyo Hwy 130, ca 20 air mi SE of Saratoga.
Moist woods. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Swan Creek and Douglas Creek, just S of Bobbie Thomson Campground, ca 37 air mi SW of Laramie.
Woods. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Little Beaver Creek, along Forest Road 542 (Keystone Road), 0.5 air mi NE of Keystone, ca 11 air mi SSW of Centennial.
Wet, open forest along creek. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: S of Elkhorn Creek and North Platte River area W of Forest Road 534, ca 48 air mi SW of Saratoga.
Meadow between creek and dry sagebrush flats. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: near Lake Owen Creek, ca 1 air mi E of Lake Owen, ca 11 air mi S of Centennial.
Unbrunt, mixed conifer and aspen grove on edge of steppe. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: South French Creek, ca 2 air mi W of intersection of Forest roads 225 and 206, ca 23 air mi SE of Saratoga.
In conifer-aspen forest. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Mullen Creek, ca 1 air mi E of intersection of Forest Road 500 (French Creek Road) and Forest Road 225 (South French Creek Road), ca 26 air mi SE of Saratoga.
Edge of forest and pond. Phenology: flowering & fruiting.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: North Fork area, just NW of North Fork Campground, running NW along Forest Road 101 (Sand Lake Road), ca 1 air mi SE of Clark Park, ca 6 air mi NW of Centennial.
Mixed conifer forest, southwest-facing slope, Vaccinium understory. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: South French Creek, just S of Forest Road 236, ca 2 air mi NE of intersection of Forest Road 225 (South French Creek Road) and Forest Road 236, ca 25 air mi SE of Saratoga and 12 air mi W of Centennial.
Edge of conifer forest and dry meadow. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: along Forest Road 208 1F, ca 1 air mi S of South Fork Corral Creek, ca 5 air mi S of Ryan Park; ca 21 air mi SE of Saratoga.
Lodgepole pine and spruce forest along creek. Phenology: fruiting.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: just S of intersection of Forest roads 232 and 210, ca 1 air mi W of Ryan Park; ca 17 air mi SE of Saratoga.
Meadow near pond. Phenology: fruiting.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Indian Creek, just N of Forest Road 527, ca 1 air mi from intersection of Forest Road 517 (Dry Park Road) and Forest Road 575, ca 11 air mi SSW of Centennial.
Clearing in forest. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: summit and north slope of Jelm Mountain, ca 24.7 air mi SW of Laramie.
Lodgepole pine forest with outcrop ridge. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Sierra Madre: Miner Creek and canyons and ridge to the NW, ca 1/4 below confluence of North and South forks, ca 4 air mi SSW of Encampment.
Easterly-facing sagebrush slope. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Platte River Wilderness: surrounding confluence of Devils Gate Creek and Douglas Creek, ca 4 air mi SE of Trail 506 Trailhead and Pike Pole Campground, ca 17 air mi SSW of Centennial.
Edge of sagebrush and forest. Phenology: flowering.
with Patricia E. Lukas

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Savage Run Wilderness: along Cottonwood Creek and Trail 502, ca 1 mi from trailhead, ca 15 air mi SW of Centennial.
Wet meadow. Phenology: flowering.
with Patricia E. Lukas

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: along Fourmile Creek near the end of improved Forest Road 329 (Fallen Pines Road), ca 1.5 air mi S of Morgan, ca 12 air mi N of Centennial; ca 10 SE of Arlington.
Along creek in mixed conifer forest. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: ca 0.5 air mi SW of Sevenmile Lake, along Sevenmile Creek, ca 10 air mi N on Centennial; ca 21 air mi S of Arlington.
Park. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: area surrounding Lincoln Park Campground, ca 4 air mi N of Ryan Park; ca 16 air mi SE of Saratoga.
Sagebrush steppe along road. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Sawmill Park, S of intersection of Forest roads 120 and 120.2F, ca 8 air mi SW of Arlington; ca 19 air mi NW of Centennial.
Dry meadow uphill from park. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Mill Creek along Forest Road 241, near intersection with Forest Road 200.3G, ca 17 air mi W of Centennial; ca 2 air mi N of Ryan Park.
Mixed conifer forest. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: Lime Kiln Park, SW of Forest Road 261 (Cedar Pass Road), ca 14 air mi E of Saratoga; ca 7 air mi N of Ryan Park.
Dry park. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: vicinity of Pass Creek, S of intersection of Forest Road 261 (Cedar Pass Road) and Forest Road 134, ca 18 air mi E of Saratoga; ca 15 air mi SW of Arlington.
Meadow uphill from creek, scattered pines. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: wetlands S of Forest Road 101 (Sand Lake Road), ca 1 air mi S of intersection with Forest Road 104, ca 40 air mi WNW of Laramie; ca 10 air mi SW of Arlington.
Park and open forest. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Game and Fish Trail 386 W, on west slope of Sheep Mountain, ca 27 air mi W of Laramie; ca 4 air mi NW of Woods Landing.
Draw with aspen overstory in sagebrush steppe. Phenology: flowering.

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Sheep Mountain, along Trail 386 (Sheep Mountain Trail), near top of Chokecherry Creek, ca 23 air mi WSW of Laramie; ca 7 air mi SE of Centennial.
Mixed conifer forest with open canopy in gravelly granite soil. Phenology: flowering.
with Bernadette Kuhn

U.S.A., Wyoming, Albany County: Medicine Bow Mountains: Sheep Mountain, starting at Trail 386 (Sheep Mountain Trail) along Johns Creek and ending at top of ridge, ca 23 air mi WSW of Laramie; ca 7 air mi SE of Centennial.
Mixed conifer forest, along creek. Phenology: flowering.
with Bernadette Kuhn

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: North Fork Rock Creek, ca 1 air mi W of intersection of Forest Road 101 (Sand Lake Road) and Forest Road 101E, ca 12 air mi NNW of Centennial; ca 9 air mi S of Arlington.
Edge of conifer forest and fen. Phenology: flowering.

U.S.A., Colorado, Larimer County: Mount Cameron.
Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: along French Creek, just S and SW of intersection of County Road 660 (French/Holmes Road) and BLM Road 3404, ca 33 air mi ESE of Encampment.
Along creek, sagebrush hills. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: W of the Platte River Wilderness, just W and SW of Elkhorn Point, ca 20 air mi SE of Encampment and ca 4 air mi N of Colorado.
Sagebrush hills. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: W of Platte River Wilderness, just NW of Elkhorn Point, ca 20 air mi SE of Encampment and ca 5 air mi N of Colorado.
Aspen and Douglas fir groves among sagebrush hills. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: just S of I-80, Wagonhound Road and Bear Creek, ca 3.5 air mi NW of exit 267 (Wagonhound) and ca 4 air mi SE of Elk Mountain (town).
Stream banks in sagebrush hills. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Medicine Bow Mountains: area between Bitter and Cedar creeks, along BLM Road 3417, ca 11 air mi E of Saratoga and ca 10 air mi NW of Ryan Park.
Aspen forest in drainage surrounded by sagebrush hills. Phenology: flowering.

U.S.A., Wyoming, Carbon County: Sierra Madre: west side of Battle Mountain, ca 9 air mi E of Savery.
Dry gravelly sagebrush steppe within mixed shrubland, west aspect, 5% slope, with Artemisia tridentata, Purshia tridentata, Festuca idahoensis. Phenology: flowering.

U.S.A., Colorado, Summit County: Gore Range: Arapaho National Forest: North Rock Creek near boundary of Eagles Nest Wilderness, ca 7 air mi NW of Silverthorne and ca 9 air mi SSE of Green Mountain Reservoir.
Mixed conifer forest and openings. Phenology: flowering.
Michael K. Kirkpatrick, 2584. 7/8/2010.

U.S.A., Colorado, Summit County: Gore Range: Arapaho National Forest: Buffalo Mountain Trail along Ryan Gulch below Eagles Nest Wilderness , ca 2.5 air mi WSW of Silverthorne.
Dry lodgepole pine forest and meadow openings. Phenology: flowering.
Michael K. Kirkpatrick, 3214. 7/23/2010.

U.S.A., Colorado, Summit County: Williams Fork Mountains: Arapaho National Forest: Cottonwood Gulch, ca 3 air mi E of Green Mountain Reservoir and 4 air mi ENE of Heeney.
Drainage flanked by aspen and Douglas fir. Phenology: flowering.
Michael K. Kirkpatrick, 3872. 8/4/2010.

U.S.A., Colorado, Summit County: Gore Range: Arapaho National Forest: Eagles Nest Wilderness: from ca 1 air mi N of Surprise Lake N to the wilderness boundary just S of Cataract Creek, ca 18.5-19 air mi NW of Silverthorne at I-70.
Aspen forest with subalpine fir. Phenology: flowering.
Accession: USFS 898331, Barcode: USFS0060048

U.S.A., Colorado, Grand County: Gore Range: from the end of Dice Hill or BLM Road 2750, ca 3/4 mi S to Dice Hill, ca 8-9 air mi SSW of Kremmling.
Second growth lodgepole pine with scattered spruce-fir-Douglas fir-aspen. Phenology: flowering.

U.S.A., Colorado, Summit County: Gore Range: Arapaho National Forest: along Forest Road 1832, ca 2 air mi ENE of Sheep Mountain, ca 25.5 air mi NW of Silverthorne at I-70.
Open aspen forest with scattered lodgepole pine and fir. Phenology: flowering & fruiting.

U.S.A., Colorado, Summit County: Williams Fork Mountains: Arapaho National Forest: lower end of Miller Gulch above Green Mountain Reservoir and Colo Hwy 9, ca 18 air mi NNW of Silverthorne at I-70.
Open Douglas fir on northerly-facing slope on shaly clay Phenology: flowering.

U.S.A., Colorado, Eagle County: Gore Range: White River National Forest: Elliott Ridge from ca 1/3 mi S of the trailhead at Blue Lake to the first saddle, ca 13-13.5 air mi N of Vail.
Dry, rocky slopes. Phenology: flowering & fruiting.

U.S.A., Colorado, Grand County: Blue Valley Ranch.
zone 13, 376964E, 4426332N; unknown, Specimen Label
Mixed conifer forest with opening and scattered aspen along road. Phenology: fruiting.

U.S.A., Colorado, Grand County: Blue Valley Ranch: E of Colo Hwy 9; E of Derringer Loop.
zone 13S, 389221E, 4424261N; unknown, Specimen Label
Aspen grove. Phenology: flowering & fruiting.

U.S.A., Wyoming, Carbon County: Sierra Madre: Green Mountain Road, ca 8 air mi SW of Encampment.
Dry roadside. Rare. Phenology: flowering & fruiting.

U.S.A., Colorado, Eagle County: Gore Range: White River National Forest: Elliott Ridge from ca 1/3 mi S of the trailhead at Blue Lake to the first saddle, ca 13-13.5 air mi N of Vail.
Dry, rocky slopes. Phenology: flowering & fruiting.
Accession: USFS (unaccessioned), Barcode: USFS0060674

U.S.A., Wyoming, Carbon County: Sierra Madre: North Fork Encampment River, ca 7 air mi SW of Encampment.
Open dry flat. Rare; flowers violet. Phenology: flowering.

U.S.A., Colorado, Montrose County: Uncompahgre Plateau: Uncompahgre National Forest: Windy Point and Iron Springs Mesa, Forest Road 507, ca 35 air mi W of Montrose.
South-facing slopes with sandstone outcrops. Phenology: flowering & fruiting.
1. Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil.

U.S.A., Colorado, Mesa County: Battlement Mesa: Grand Mesa National Forest: Brush Creek Trail to Battlement Trail, ca 46 air mi NW of Grand Junction.
Open meadow on south-facing slope. Phenology: flowering & fruiting.
1. Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil.

U.S.A., Colorado, Ouray County: Uncompahgre Plateau: above East Fork Spring Creek, off of Forest Road 532, 3.1 road mi N of Divide or Forest Road 402, ca 17 air mi SSW of Montrose.
Subalpine meadow. Phenology: flowering.
1. Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil.

U.S.A., Colorado, Ouray County: Uncompahgre Plateau: Happy Canyon Rim, Forest Road 510.3C off of Dave Wood Road, ca 15 air mil SSW of Montrose.
Ponderosa pine on sandstone pavement. Phenology: flowering.
with Joe E. Brummer

U.S.A., Wyoming, Carbon County: Sierra Madre: Jack Creek Road, ca 6 air mi WSW of Encampment.
Mixed forest. Phenology: flowering & fruiting.

U.S.A., Colorado, Teller County: East-central Colorado: Mosquito Range to Plains: Rampart Range: USFS Woodland Park Work Center, 1400 Rampart Range Road or County Road 22, ca 2 road mi N of intersection with U.S. Hwy 24, ca 2 air mi N of Woodland Park.
On slopes in open ponderosa pine forest. Phenology: flowering.

U.S.A., Colorado, Douglas County: East-central Colorado: Mosquito Range to Plains: Rampart Range: along Jackson Creek, ca 1 air mi N of intersection of Forest Road 300 or Rampart Range Road and Forest Road 507 or Jackson Creek Road, ca 17 air mi N of Woodland Park.
In an open, grassy flat adjacent to the creek. Phenology: flowering.

U.S.A., Wyoming, Carbon County: [location and coordinates withheld]
Under limber pine. Phenology: flowering.
with Amy J. Roderick

Cirsium clavatum var. clavatum (2011)
Cirsium clavatum (M. E. Jones) Petr. var. clavatum
U.S.A., Colorado, Grand County: Blue River Valley: between the river and the north end of Lawson Ridge E of Colo Hwy 9, ca 4 air mi S of Kremmling.
Clay slopes and bottom of gully in sagebrush. Phenology: flowering & fruiting.

Cirsium clavatum var. clavatum (2012)
Cirsium clavatum (M. E. Jones) Petr. var. clavatum
U.S.A., Colorado, Mesa County: Uncompahgre Plateau: Uncompahgre National Forest: Dominguez Ridge, just off of Brushy Ridge Trail or Forest Road 409, ca 30 air mi WSW of Delta.
Gambel oak mixed mountain shrub community. Phenology: flowering.

Cirsium clavatum var. clavatum (2012)
Cirsium clavatum (M. E. Jones) Petr. var. clavatum
U.S.A., Colorado, Ouray County: San Juan Mountains: Uncompahgre National Forest: Cimarron Ridge; Lou Creek Pass, ridge just S of Lou Creek Pass then W on Lou Creek Pass Trail to ridge above Kennedy Mine, ca 11 air mi NNE of Ridgway.
Moist meadow in aspen/spruce/fir mix. Phenology: flowering.
1. Cirsium clavatum (M. E. Jones) Petr. var. clavatum .

U.S.A., Colorado, Gunnison County: Gunnison National Forest: S of McClure Pass, Raggeds Trail 820, ca 23 air mi NW of Paonia.
Riparian area in aspen. Phenology: flowering & fruiting.
1. Cirsium clavatum (M. E. Jones) Petr. var. clavatum .

U.S.A., Colorado, Gunnison County: West Elk Mountains: Soap Creek Drainage, along Little Soap Park or Forest Road 721 for ca 1 mi S of park area, ca 28 air mi WNW of Gunnison.
Spruce/aspen on gravelly soil with Bromus, Rubus, Symphoricarpos. Phenology: flowering & fruiting.

Cirsium clavatum var. osterhoutii (1906)
Cirsium clavatum (M. E. Jones) Petr. var. osterhoutii (Rydb.) D. J. Keil
U.S.A., Colorado, Gilpin County: Toland.
3. Cirsium clavatum (M. E. Jones) Petr. var. osterhoutii (Rydb.) D. J. Keil

Cirsium clavatum var. osterhoutii (1906)
Cirsium clavatum (M. E. Jones) Petr. var. osterhoutii (Rydb.) D. J. Keil
U.S.A., Colorado, Lake County: Tennessee Pass.
2. Cirsium clavatum (M. E. Jones) Petr. var. osterhoutii (Rydb.) D. J. Keil

Cirsium clavatum var. osterhoutii (1906)
Cirsium clavatum (M. E. Jones) Petr. var. osterhoutii (Rydb.) D. J. Keil
U.S.A., Colorado, Eagle County: Red Cliff.
3. Cirsium clavatum (M. E. Jones) Petr. var. osterhoutii (Rydb.) D. J. Keil

U.S.A., Colorado, Rio Blanco County: White River National Forest: Sleepy Cat.
Sandy soil. Phenology: flowering & fruiting.
William T. Kirkpatrick, 274. 8/10/1913.

U.S.A., Colorado, El Paso County: Ruxton Dell
Elev. 2950 m.
Herbaria Formationum Coloradensium. Phenology: flowering & fruiting.
with E. S. Clements

U.S.A., Colorado, Summit County: Near Breckenridge.
Kenneth K. Mackenzie, 324. 8//1901.

U.S.A., Colorado, Clear Creek County: Silver Plume.

George E. Osterhout, 3362a. 8/16/1906.

U.S.A., Colorado, Lake County: Tennessee Pass.

Collection cited by Rydberg (1910, Bull. Torrey Bot. Club 37: 549) as Carduus griseus x C. parryi, and by Petrak (1917, Bieh. Bot. Centralbl. 35: 562) as Cirsium griseum x C. parryi with the combination C. xgriseiforme was not validly published. I do not consider this plant to be a hybrid.-Keil. Phenology: flowering & fruiting.

U.S.A., Colorado, Eagle County: Gore Range: White River National Forest: Eagles Nest Wilderness: Deluge Lake Trail, ca 7 air mi NNW of Vail Pass.
Rocky aspen hillsides with riparian channels. Phenology: flowering.
Accession: USFS 898315, Barcode: USFS0060033

U.S.A., Colorado, Summit County: Front Range: Arapaho National Forest: Bakers Tank, Boreas Pass Road (Forest Road 10), ca 3 air mi SE of Breckenridge.
Riparian meadow with scattered pine and spruce. Phenology: flowering.

U.S.A., Colorado, Eagle County: Sawatch Range: White River National Forest: unnamed wet meadow along Missouri Creek, ca 15 air mi S of Dowds Junction.
Subalpine fen. Phenology: flowering.

U.S.A., Colorado, Eagle County: Gore Range: White River National Forest: Freeman Creek drainage N of Moniger-Muddy Pass Road (Forest Road 701), ca 5 air mi NW of I-70 exit 176 at Vail.
Dry subalpine meadow. Phenology: flowering.

U.S.A., Colorado, Eagle County: Sawatch Range: White River National Forest: Wurts Ditch Road (Forest Road 705) near the headwaters of Mitchell Creek, ca 2.5 air mi W of Tennessee Pass.
Subalpine forest, openings, and roadside. Phenology: flowering.

U.S.A., Colorado, Pitkin County: Elk Mountains: White River National Forest: along Avalanche Creek from the trailhead at the end of Forest Road 310 SE to the wilderness boundary, ca 4 air mi NNE of Redstone; ca 11-12 air mi S of Carbondale.
Brushy canyon bottom with conifers, aspen, and cottonwood, and streambank. Phenology: flowering.

U.S.A., Colorado, Pitkin County: Sawatch Range: White River National Forest: along Lincoln Creek between Roaring Fork River and New York Creek, ca 6 air mi W of Independence Pass, ca 10 air mi SE of Aspen.
Rocky ridge and slopes and edge of lodgepole pine forest. Phenology: flowering.

U.S.A., Colorado, Gunnison County: Elk Mountains: White River National Forest: upper part of Crystal Canyon to Schofield Park, along jeep trail, ca 14 air mi NNW of Crested Butte.
Along riparian area in subalpine. Phenology: flowering.

U.S.A., Colorado, Gunnison County: Elk Mountains: White River National Forest: Maroon Bells-Snowmass Wilderness: Silver Creek Pass and area around Silver Creek Trail, ca 5 air mi NE of Marble.
Rocky alpine ridge and slopes. Phenology: flowering.

U.S.A., Colorado, Gunnison County: Elk Mountains: White River National Forest: Maroon Bells-Snowmass Wilderness: upper East Fork Trail to Maroon Pass, ca 13.5 air mi N of Crested Butte.
Rock outcrop in alpine. Phenology: flowering.

U.S.A., Colorado, Gunnison County: Elk Mountains: White River National Forest: Maroon Bells-Snowmass Wilderness: Hasley Basin Trail from East Fork Trail, ca 13 3/4 air mi NNW of Crested Butte.
Alpine meadow. Phenology: flowering.

U.S.A., Colorado, Eagle County: Sawatch Range: White River National Forest: Holy Cross Wilderness: Eagle Lake Trail to Halfmoon Lake, between Eagle and Avalanche peaks, along Lime Creek, ca 18 air mi SSE of Eagle.
Subalpine forest and roadside meadow with seeps. Phenology: flowering.

U.S.A., Colorado, Eagle County: Sawatch Range: White River National Forest: Tellurium Lake Trail, off of Forest Road 506 (Burnt Mountain Road), ca 20 air mi SSE of Eagle.
Subalpine rocky meadows, boulder fields, and roadside. Phenology: flowering & fruiting.

U.S.A., Colorado, Pitkin County: Sawatch Range: White River National Forest: Collegiate Peaks Wilderness: the Continental Divide from W of Grizzly Peak, ca 15 air mi SE of Aspen.
Alpine slopes and talus fields. Phenology: flowering.

U.S.A., Colorado, Pitkin County: Elk Mountains: White River National Forest: Maroon Bells-Snowmass Wilderness: ridge and slopes NW of Mt. Daly and Capitol Peak, E of Capitol Creek, ca 13 air mi W of Aspen.
Alpine ridge with exposed siltstone, granite cliffs, and talus slopes. Phenology: flowering.

U.S.A., Colorado, Gunnison County: Elk Mountains: White River National Forest: Maroon Bells-Snowmass Wilderness: cirque basin between Geneva Lake and Hagerman Peak, ca 7 air mi ENE of Marble.
Subalpine rocky meadow with willows and forb understory. Phenology: flowering.

U.S.A., Colorado, Delta County: Grand Mesa: Grand Mesa National Forest: Twin Lakes; slope N of Twin Lake #2 south to E side of Twin Lake #1, ca 12 3/4 air mi NE of Cedaredge.
Moist subalpine meadows. Phenology: flowering.

U.S.A., Colorado, Delta County: Grand Mesa: Grand Mesa National Forest: Crag Crest Trail, high point of trail, ca 3.5 trail mi from west trailhead, to ca 1.5 trail mi ENE of trailhead, ca 11 air mi NNW of Cedaredge.
Along rocky subalpine ridge. Mesa and Delta county. Phenology: flowering.

U.S.A., Colorado, Delta County: Grand Mesa: Gunnison National Forest: Chalk Mountain, southeast slope to Overland Reservior, ca 17.5 air mi NNW of Paonia.
Subalpine meadow. Phenology: flowering.
with Joe E. Brummer

U.S.A., Colorado, Delta County: Grand Mesa: Gunnison National Forest: Chalk Mountain, southeast slope to Overland Reservior, ca 17.5 air mi NNW of Paonia.
Bare north-facing subalpine slope. Phenology: flowering.
with Joe E. Brummer

U.S.A., Colorado, Delta County: Grand Mesa: Grand Mesa National Forest: ridge off of Forest Road 129, SE of Kiser Reservoir, ca 9 air mi N of Cedaredge.
Subalpine meadow. Phenology: flowering.

U.S.A., Colorado, Eagle County: Sawatch Range: White River National Forest: Holy Cross Wilderness: Eagle Lake Trail to Halfmoon Lake, between Eagle and Avalanche peaks, along Lime Creek, ca 18 air mi SSE of Eagle.
Subalpine forest and roadside meadow with seeps. Phenology: flowering.
Accession: USFS (unaccessioned), Barcode: USFS0060673

U.S.A., Colorado, Mesa County: Grand Mesa: Grand Mesa National Forest: Skyway Ski Trail and Scales Lakes, ca 30 air mi E of Grand Junction.
Subalpine meadow with rocky outcrops and low wet areas. Phenology: flowering & fruiting.
with Bernadette Kuhn, Margarette Lyon

U.S.A., Colorado, Delta County: Grand Mesa: Grand Mesa National Forest: stream below Sackett Reservoir and adjoining roadside, ca 40 air mi E of Grand Junction.
Along small stream in moist spruce/fir forest on steep slopes and adjoining roadside. Phenology: flowering.

U.S.A., Colorado, Mesa County: Grand Mesa: Grand Mesa National Forest: Lands End near Bolen Reservoir, ca 20 air mi ESE of Grand Junction.
Upland area under spruce next to small creek. Phenology: flowering.

U.S.A., Colorado, Mesa County: Uncompahgre Plateau: La Fair Creek off of Divide Road (Forest Road 402), ca 30 air mi W of Delta.
Ponderosa pine woodland with scattered aspen. Phenology: flowering.
with Linda Deeds, Kim Hansen