About Cirsium edule Nutt.
Cirsium edule Nutt., commonly known as edible thistle or Indian thistle, is a thistle species in the genus Cirsium native to western North America. Its range extends from southeastern Alaska south through British Columbia to Washington and Oregon, reaching locally inland to Idaho. It serves as a larval host plant for the mylitta crescent and the painted lady. This is a tall herbaceous perennial plant that grows 1 to 2 meters (39 to 79 inches) in height. Its leaves are very spiny and lobed, measuring 10 to 30 cm long and 2 to 5 cm broad, with smaller leaves on the upper section of the flower stem. The inflorescence is 3 to 4 cm in diameter, purple, and made up of numerous disc florets with no ray florets. Its achenes are 4 to 5 mm long, with a downy pappus that helps the seeds disperse via wind. The species is monocarpic: it grows as a low leaf rosette for multiple years, then produces a tall flowering stem in spring, and dies after its seeds mature. Native Americans use edible thistle for its edible roots and young shoots. The roots have a sweet flavor, but they contain inulin, which causes digestive issues for some people. Three varieties are recognized: Cirsium edule var. edule, found in Oregon and Washington; Cirsium edule var. macounii (Greene) D.J.Keil, found in Oregon, Washington, British Columbia, and Alaska; and Cirsium edule var. edule wenatchense D.J.Keil, found in Washington.
