Cirsium edule, the edible thistle or Indian thistle, is a species of thistle in the genus Cirsium, native to western North America from southeastern Alaska south through British Columbia to Washington and Oregon, and locally inland to Idaho.Biota of North America Program 2014 state-level distribution map It is a larval host to the mylitta crescent and the painted lady.The Xerces Society (2016), Gardening for Butterflies: How You Can Attract and Protect Beautiful, Beneficial Insects, Timber Press.
Cirsium edule is a tall herbaceous perennial plant, reaching in height. The leaves are very spiny, lobed, 10–30 cm long and 2–5 cm broad (smaller on the upper part of the flower stem). The inflorescence is 3–4 cm diameter, purple, with numerous disc florets but no ray florets. The achenes are 4–5 mm long, with a downy pappus which assists in wind dispersal. It is monocarpic, growing as a low rosette of leaves for a number of years, then sending up the tall flowering stem in spring, with the plant dying after seed maturation.Flora of North America, Edible thistle, cardon, Cirsium edule Nuttall, Trans. Amer. Philos. Soc., n. s. 7: 420. 1841.
Edible thistle is used by Native Americans for its edible roots and young shoots. The roots are sweet, but contain inulin, which gives some people digestive problems.Plants for a Future: Cirsium edule
Varieties Cirsium edule var. edule - Oregon, Washington Cirsium edule var. macounii (Greene) D.J.Keil - Oregon, Washington, British Columbia, Alaska Cirsium edule var. edule wenatchense D.J.Keil - WashingtonKeil, David John 2004. Sida 21(1): 213
References
External links Turner Photographics Pacific Northwest Wildflowers Lady Bird Johnson Wildflower Center, University of Texas Calphotos photo gallery, University of California Paul Slichter, Thistles East of the Cascade Mountains, Indian Thistle, Edible Thistle Cirsium edule var. wenatchense