Dinnerplate Thistle, Elk Thistle, Meadow Thistle, Sessile Thistle, Shasta Valley Thistle, Stemless Thistle, Toiyabe Thistle: Cirsium scariosum (Synonyms: Carduus americanus, Carduus coloradensis, Cirsium acaule var. americanum, Cirsium acaulescens, Cirsium americanum, Cirsium butleri, Cirsium coloradense, Cirsium coloradense ssp. acaulescens, Cirsium coloradense ssp. longissimum, Cirsium congdonii, Cirsium drummondii ssp. lanatum, Cirsium drummondii ssp. lanatum, Cirsium drummondii ssp. latisquamum, Cirsium drummondii ssp. vexans, Cirsium drummondii var. acaulescens, Cirsium drummondii var. oregonense, Cirsium erosum, Cirsium hookerianum var. scariosum, Cirsium kelsey, Cirsium lacerum, Cirsium magnificum, Cirsium minganense, Cirsium oreophilum, Cirsium quercetorum, Cirsium scariosum var. americanum, Cirsium scariosum var. robustum, Cirsium scariosum var. scariosum, Cirsium scariosum var. thorneae, Cirsium scariosum var. toiyabense, Cirsium tioganum, Cirsium tioganum var. coloradense, Cirsium tioganum var. tioganum, Cnicus drummondii var. acaulescens, Cnicus tioganus)

[Thistles East of the Cascade Mts. of Oregon and Washington]

Dinnerplate Thistle, Elk Thistle, Meadow Thistle, Sessile Thistle, Shasta Valley Thistle, Stemless Thistle, Toiyabe Thistle

Cirsium scariosum

Synonyms: Carduus americanus, Carduus coloradensis, Cirsium acaule var. americanum, Cirsium acaulescens, Cirsium americanum, Cirsium butleri, Cirsium coloradense, Cirsium coloradense ssp. acaulescens, Cirsium coloradense ssp. longissimum, Cirsium congdonii, Cirsium drummondii ssp. lanatum, Cirsium drummondii ssp. lanatum, Cirsium drummondii ssp. latisquamum, Cirsium drummondii ssp. vexans, Cirsium drummondii var. acaulescens, Cirsium drummondii var. oregonense, Cirsium erosum, Cirsium hookerianum var. scariosum, Cirsium kelsey, Cirsium lacerum, Cirsium magnificum, Cirsium minganense, Cirsium oreophilum, Cirsium quercetorum, Cirsium scariosum var. americanum, Cirsium scariosum var. robustum, Cirsium scariosum var. scariosum, Cirsium scariosum var. thorneae, Cirsium scariosum var. toiyabense, Cirsium tioganum, Cirsium tioganum var. coloradense, Cirsium tioganum var. tioganum, Cnicus drummondii var. acaulescens, Cnicus tioganus

The photo above shows a close-up of elk thistle (possibly var. scariosum) as seen at Herren Meadow along the Blue Mt. Scenic Highway to the southeast of Heppner, OR........................June 22, 2007. Note the numerous spreading hairs on both leaf surfaces.

Dinnerplate Thistle, Elk Thistle, Meadow Thistle, Sessile Thistle, Shasta Valley Thistle, Stemless Thistle, Toiyabe Thistle: Cirsium scariosum (Synonyms: Carduus americanus, Carduus coloradensis, Cirsium acaule var. americanum, Cirsium acaulescens, Cirsium americanum, Cirsium butleri, Cirsium coloradense, Cirsium coloradense ssp. acaulescens, Cirsium coloradense ssp. longissimum, Cirsium congdonii, Cirsium drummondii ssp. lanatum, Cirsium drummondii ssp. lanatum, Cirsium drummondii ssp. latisquamum, Cirsium drummondii ssp. vexans, Cirsium drummondii var. acaulescens, Cirsium drummondii var. oregonense, Cirsium erosum, Cirsium hookerianum var. scariosum, Cirsium kelsey, Cirsium lacerum, Cirsium magnificum, Cirsium minganense, Cirsium oreophilum, Cirsium quercetorum, Cirsium scariosum var. americanum, Cirsium scariosum var. robustum, Cirsium scariosum var. scariosum, Cirsium scariosum var. thorneae, Cirsium scariosum var. toiyabense, Cirsium tioganum, Cirsium tioganum var. coloradense, Cirsium tioganum var. tioganum, Cnicus drummondii var. acaulescens, Cnicus tioganus)

Photo at right of elk thistle from near Picture Rock Pass, Lake County, OR.......July 3, 1996.

Characteristics:

A fairly easy thistle to identify in that it is frequently without stems. Stems generally very short and thick, with the flower heads sessile. Corollas white to a pale pink-purple. Leaves spiny, but entire to somewhat scalloped. Flowers from June into August.

Habitat:

Meadows and other moist places from the foothills to 3200 m.

Range:

Found from southern British Columbia to Alberta, south along the eastern edges of the Cascades and Sierra Nevada to southern California, and east to central Arizona.

The photo above shows a close-up of the inflorescence of elk thistle (possibly var. scariosum) as seen at Herren Meadow along the Blue Mt. Scenic Highway to the southeast of Heppner, OR........................June 22, 2007.

Elk thistle as seen along Forest Service Road #1647 in southeastern Logan Valley, Malheur National Forest................July 18, 2010.

Close-up photos of elk thistle (var. americanum?) as seen in the vernally moist meadows of Logan Valley just west of Big Creek Campground, Malheur National Forest................July 2, 2010.

An interesting glabrous-leaved elk thistle as seen in roadside gravels in Summit Prairie, Malheur National Forest...................August 20, 2011.

Elk thistle (var. americanum) from Newberry Crater Volcanic National Monument........August 1994.

Paul Slichter