Berberis aquifolium

Berberis aquifolium, the Oregon grape<ref name="tktimb">Template:Cite book</ref> or holly-leaved barberry, is a North American species of flowering plant in the family Berberidaceae. It is an evergreen shrub growing up to Template:Convert tall and Template:Convert wide. It has pinnate leaves consisting of spiny leaflets, exhibiting dense clusters of yellow flowers in early spring, followed by dark bluish-black berries.

The berries are a part of the traditional diet of some indigenous peoples of the Pacific Northwest and the species serves as the state flower of Oregon.

Description

Berberis aquifolium grows to Template:Convert tall<ref>Template:Cite web</ref> and Template:Convert wide. The stems and twigs have a thickened, corky appearance. The leaves are pinnate and up to Template:Convert long, comprising 5–7 ovate, spiny leaflets up to Template:Convert long.<ref name="auduflo">Template:Cite book</ref> Shiny on top, the leathery leaves resemble those of holly.<ref name="auduflo" />

From March to June, the yellow flowers are borne in dense clusters Template:Convert long and Template:Convert wide.<ref name="auduflo" /><ref name="Jepson" /> 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 up to Template:Convert wide,<ref name="tktimb" /> dark dusty-blue, and tart in taste.<ref name="Jepson">Template:Cite web</ref><ref name=":0">Template:Cite web</ref>

Chemistry

Berberis aquifolium contains 5'-methoxyhydnocarpin (5'-MHC), a multidrug resistance pump inhibitor, which works to decrease bacterial resistance in vitro.<ref>Template:Cite journal</ref>

Similar species

Berberis nervosa (Cascade Oregon grape) is similar but has 7–23 leaflets.<ref name="auduflo" />

Taxonomy

Some botanists continue to place part of the barberry genus Berberis in a separate genus, Mahonia.<ref name="FNA Berberis">Template:Cite web</ref><ref>Loconte, H., & J. R. Estes. 1989. Phylogenetic systematics of Berberidaceae and Ranunculales (Magnoliidae). Systematic Botany 14:565-579.</ref><ref>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.</ref><ref>Laferrière, Joseph E. 1997. Transfer of specific and infraspecific taxa from Mahonia to Berberis. Bot. Zhurn. 82(9):96-99.</ref> Under this classification Berberis aquifolium is named Mahonia aquifolium.<ref>Template:Cite POWO</ref> As of 2023 Plants of the World Online classifies it as Berberis aquifolium with no valid subspecies.<ref name="POWO">Template:Cite POWO</ref>

Berberis dictyota is considered a variety.<ref name="tktimb" />

Etymology

The Latin specific epithet aquifolium denotes "sharp-leafed" (as in Ilex aquifolium, the common holly), referring to the spiny foliage.<ref name="RHSLG">Template:Cite book</ref>Template:Citation needed

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.<ref name="MBG Plant Finder">Template:Cite web</ref>

Distribution and habitat

Berberis aquifolium is a native plant in the North American West from Southeast Alaska to Northern California to central New Mexico, often occurring in the understory of Douglas-fir forests (although other forest types contain the species) and in brushlands in the Cascades, Rockies, and northern Sierra Nevada.Template:Citation needed

Ecology

Flowers visited by a bumblebee

As with some other Berberis, B. aquifolium can serve as an alternate host for wheat yellow rust (Puccinia striiformis f. sp. tritici, which usually prefers wheat), but it is unknown whether this occurs naturally.<ref name="Wang-Chen-2013" />

Wildlife consume the berries.<ref name="auduflo" />

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.<ref name="RHSAZ">Template:Cite book</ref>

Numerous cultivars and hybrids have been developed, of which the following have gained the Royal Horticultural Society's Award of Garden Merit:<ref>Template:Cite web</ref>

• M. × wagneri 'Pinnacle'<ref>Template:Cite web</ref> (B. aquifolium × Berberis pinnata)
• 'Apollo'<ref>Template:Cite web</ref>

Uses

The small purplish-black fruits, which are quite tart and contain large seeds, are edible raw<ref>Template:Cite book</ref> after the season's first frosts.<ref>Template:Cite book</ref> They were included in small quantities in the traditional diets of Pacific Northwest tribes, mixed with salal or another sweeter fruit. Today, they are sometimes used to make jelly, alone or mixed with salal.<ref name="auduflo" /><ref>Template:Cite book</ref> 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.<ref>Template:Cite book</ref>

The inner bark of the larger stems and roots of Oregon grape yield a yellow dye.<ref name="auduflo" /> The berries contain a dye that can be purple,<ref>Template:Cite book</ref> 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.Template:Or

Medicinal uses

Some indigenous peoples of the Northwest Plateau use Oregon grape for indigestion.<ref name="hunn">Template:Cite book</ref>

The plant contains berberine and reportedly has antimicrobial properties similar to those of goldenseal.<ref>Template:Cite web</ref>

In culture

In 1899, Oregon-grape was recognized as the state flower of Oregon.<ref>Template:Cite web</ref>

External links

• 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
• Calflora Database: Berberis aquifolium (Oregon grape, mountain grape)
• Flora of North America @ efloras.org: Berberis aquifolium — syn; formerly: Mahonia aquifolium
• UC Photos gallery: Berberis aquifolium
• Mountain Grape from Botanical.com