Berberis aquifolium, the Oregon grape or holly-leaved barberry, is a species of flowering plant in the family Berberidaceae, native to western North America. It is an evergreenshrub growing 1–3 meters (3–10 feet) tall and 1.5 m (5 ft) wide, with pinnate leaves consisting of spiny leaflets, and dense clusters of yellow flowers in early spring, followed by dark bluish-black berries.[2]
The berries are included in the diet of some aboriginal peoples of the Pacific Northwest, and the species is recognized as the state flower of Oregon.
Description
Berberis aquifolium grows to 1–3 metres (3+1⁄2–10 feet) tall[3] by 1.5 m (5 ft) wide. The stems and twigs have a thickened, corky appearance. The leaves are pinnate and up to 30 centimetres (12 inches) long, comprising spiny leaflets. The leathery leaves resemble those of holly. The yellow flowers are borne in dense clusters 3–6 cm (1+1⁄4–2+1⁄4 in) long in late spring. Each of the six stamens terminates in two spreading branches. The six yellow petals are enclosed by six yellow sepals. At the base of the flower are three greenish-yellow bracts, less than half as long as the sepals. The spherical berries are dark dusty-blue and tart in taste.[4][5]
Some botanists continue to place part of the barberry genus Berberis in a separate genus, Mahonia.[7][8][9][10] Under this classification Berberis aquifolium is named Mahonia aquifolium.[11] As of 2023 Plants of the World Online (POWO) classifies it as Berberis aquifolium with no valid subspecies.[1]
Berberis aquifolium is not closely related to either the true holly (Ilex aquifolium) or the true grape (Vitis), but its common name, Oregon-grape holly comes from its resemblance to these plants.[13]
As with some other Berberis, Berberis aquifolium can serve as an alternate host for Wheat yellow rust (Puccinia striiformis f. sp. tritici; the primary host of Pst being wheat). However, in B. aquifolium this was only achieved by intentional inoculation in a lab, and it remains unknown whether this occurs naturally.[14]
In some areas outside its native range, Berberis aquifolium has been classified as an invasive exotic species that may displace native vegetation.[15][16]
Cultivation
Berberis aquifolium is a popular subject in shady or woodland plantings. It is valued for its striking foliage and flowers, which often appear before those of other shrubs. It is resistant to summer drought, tolerates poor soils, and does not create excessive leaf litter. Its berries attract birds.[2]
The small purplish-black fruits, which are quite tart and contain large seeds, are edible raw[20] after the season's first frosts.[21] They were included in small quantities in the traditional diets of Pacific Northwest indigenous peoples, mixed with salal or another sweeter fruit. Today, they are sometimes used to make jelly, alone or mixed with salal.[22] Oregon-grape juice can be fermented to make wine, similar to European barberry wine folk traditions, although it requires an unusually high amount of sugar.[23]
The inner bark of the larger stems and roots of Oregon grape yield a yellow dye. The berries contain a dye that can be purple,[24] blue, pink, or green depending on the pH of water used to make the dye, due to the berries containing a naturally occurring pH indicator.[original research?]
^ a bRHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 978-1-4053-3296-5.
^"Landscape Plants: Mahonia aquifolium". Oregon State University: College of Agricultural Sciences - Department of Horticulture. Oregon State University. Retrieved 4 July 2020.
^Williams, Michael P. (2012). "Berberis aquifolium, in Jepson Flora Project (eds.)". Jepson eFlora. Retrieved 2013-08-08.
^Stermitz FR, Lorenz P, Tawara JN, Zenewicz LA, Lewis K (February 2000). "Synergy in a medicinal plant: antimicrobial action of berberine potentiated by 5'-methoxyhydnocarpin, a multidrug pump inhibitor". Proc. Natl. Acad. Sci. U.S.A. 97 (4): 1433–7. Bibcode:2000PNAS...97.1433S. doi:10.1073/pnas.030540597. PMC 26451. PMID 10677479.
^Whittemore, Alan T. "Berberis in Flora of North America". efloras. Archived from the original on 29 May 2023. Retrieved 6 November 2023.
^Loconte, H., & J. R. Estes. 1989. Phylogenetic systematics of Berberidaceae and Ranunculales (Magnoliidae). Systematic Botany 14:565-579.
^Marroquín, Jorge S., & Joseph E. Laferrière. 1997. Transfer of specific and infraspecific taxa from Mahonia to Berberis. Journal of the Arizona-Nevada Academy of Science 30(1):53-55.
^Laferrière, Joseph E. 1997. Transfer of specific and infraspecific taxa from Mahonia to Berberis. Bot. Zhurn. 82(9):96-99.
^Wang, M. N.; Chen, X. M. (2013). "First Report of Oregon Grape (Mahonia aquifolium) as an Alternate Host for the Wheat Stripe Rust Pathogen (Puccinia striiformis f. sp. tritici) Under Artificial Inoculation". Plant Disease. 97 (6). American Phytopathological Society: 839. doi:10.1094/pdis-09-12-0864-pdn. ISSN 0191-2917. PMID 30722629. S2CID 73433566.
^"North Carolina Botanical Garden / Conservation / Plants to Avoid in the Southeastern United States". Archived from the original on 2011-10-19. Retrieved 2007-05-13.
^Plants to Avoid in the Southeastern United States Tennessee Invasive Exotic Plant List
^"AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 62. Retrieved 25 March 2018.
^Benoliel, Doug (2011). Northwest Foraging: The Classic Guide to Edible Plants of the Pacific Northwest (Rev. and updated ed.). Seattle, WA: Skipstone. p. 119. ISBN 978-1-59485-366-1. OCLC 668195076.
^Lyons, C. P. (1956). Trees, Shrubs and Flowers to Know in Washington (1st ed.). Canada: J. M. Dent & Sons. p. 196.
^Pojar, Jim; MacKinnon, Andy, eds. (1994). Plants of Coastal British Columbia: including Washington, Oregon & Alaska, rev. ed. Vancouver: Lone Pine Publishing. p. 95. ISBN 978-1-55105-532-9.
^Henderson, Robert K. (2000). The Neighbourhood Forager. Toronto, Ontario: Key Porter Books. p. 111. ISBN 1-55263-306-3.
^Bliss, Anne (1993). North American Dye Plants, rev. and enl. ed. Loveland, Colorado: Interweave Press. p. 130. ISBN 0-934026-89-0.
^"State Symbols: Dance to Hops - Flower, State". Oregon Blue Book. Oregon Secretary of State. 2021. Retrieved 10 May 2021.
External links
Wikisource has texts related to Berberis aquifolium.
The Oregon Grape in "Our State Flowers: The Floral Emblems Chosen by the Commonwealths", The National Geographic Magazine, XXXI (June 1917), pp. 481–517.
Mahonia aquifolium images at bioimages.vanderbilt.edu
Jepson eFlora (TJM2) treatment of Berberis aquifolium