W. North America, BC to N. Mexico (PNW native)
"Cascade barberry is an important component of both seral and climax communities of the Pacific Northwest. It occurs in recent clearcuts as well as in stands 300 to 600 years or older. It is a woody survivor or residual colonizer, generally increasing dramatically after low intensity disturbances such as light fires. It commonly persists on cutover or lightly burned sites. Residual survivors sprouted soon after the eruption of Mount St. Helens and were particularly evident in protected microsites such as near the bases or rootwads of trees." [1]
"It was sufficiently common that Lewis and Clark collected it on their 1805 visit to the Lower Columbia River. They brought back many new species from their expedition, and this one was described to science in 1813 by Frederick T. Pursh, a German-American botanist..." [2]
"The berries are edible but quite tart and are better used for jelly. The holly-like leaves are often used in floral arrangements. An alkaloid called berberine colors the inner bark yellow, and the shredded bark has long been used to make a yellow dye. Both the bark and the berries are used medicinally by Native Americans, and modern medicine uses it as a fairly potent medicine against parasites, bacteria, and viruses. It has also been used to treat diabetes and to reduce cholesterol levels." [2]
[1] Tirmenstein, D. A. 1990. Mahonia nervosa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: https://www.fs.fed.us/database/feis/plants/shrub/mahner/all.html [2020, May 10].
[2] “Dull Oregon-Grape (Mahonia Nervosa).” Slater Museum of Natural History, www.pugetsound.edu/academics/academic-resources/slater-museum/exhibits/terrestrial-panel/dull-oregon-grape/.