Page authors: Don Knoke, David Giblin
Cirsium scariosum
elk thistle, meadow thistle
Specimens
Photos

Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.

Habitat: Wet meadows, moist, sometimes alkaline ground, and forest openings from the foothills to fairly high elevations in the mountains.

Flowers: June-August

Origin: Native

Growth Duration: Biennial, Perennial

Conservation Status: Not of concern

Pollination: Bumblebees, bees, butterflies, beetles, hummingbirds

Description:
General:

Herbaceous perennial from a taproot, often acaulescent, or the stem up to 1 m. tall, thick and succulent, tapering slightly upward, somewhat spider-webby.

Leaves:

Leaves numerous in a basal rosette in the acaulescent form, alternate in the cauline form; leaves spider-webby on the upper surface, slightly woolly below, weakly spiny, coarsely toothed to pinnatifid, broadly linear.

Flowers:

Heads densely clustered at the top of the stem, over-topped by the subtending leaves; involucre 2-3.5 cm. high, nearly glabrous, its bracts broad, well imbricate, the outer with short, erect spine tip, the inner less spiny and often with a scarious, fringed tip; flowers all tubular and perfect, the corollas whitish to pale pink or purplish, unequally cleft, the deepest sinuses 5-8 mm. deep, the tube about twice as long as the throat.

Fruits:

Achene.

Accepted Name:
Cirsium scariosum Nutt.
Publication: Trans. Amer. Philos. Soc., n. s. 7: 420. 1841.

Synonyms & Misapplications:
Cirsium hookerianum Nutt. var. scariosum (Nutt.) B. Boivin
Cirsium magnificum (A. Nelson) Petr. [HC]
Cirsium scariosum Nutt. var. americanum (A. Gray) D.J. Keil [FNA19]
Cirsium scariosum Nutt. var. citrinum (Petr.) D.J. Keil [FNA19]
Cirsium scariosum Nutt. var. coloradense (Rydb.) D.J. Keil [FNA19]
Cirsium scariosum Nutt. var. congdonii (R.J. Moore & Frankton) D.J. Keil [FNA19]
Cirsium scariosum Nutt. var. robustum D.J. Keil [FNA19]
Cirsium scariosum Nutt. var. scariosum [FNA19]
Cirsium scariosum Nutt. var. thorneae S.L. Welsh [FNA19]
Cirsium scariosum Nutt. var. toiyabense D.J. Keil [FNA19]
Cirsium tioganum (Congdon) Petr. var. tioganum
Additional Resources:

PNW Herbaria: Specimen records of Cirsium scariosum in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Cirsium scariosum checklist entry

OregonFlora: Cirsium scariosum information

E-Flora BC: Cirsium scariosum atlas page

CalPhotos: Cirsium scariosum photos

28 photographs:
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