| Dull Oregon-grape | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Ranunculales |
| Family: | Berberidaceae |
| Genus: | Berberis |
| Species: | B. nervosa |
| Binomial name | |
| Berberis nervosa | |
| Synonyms[1] | |
| |
Berberis nervosa, commonly known asdwarf Oregon-grape,Cascade barberry,Cascade Oregon-grape, ordull Oregon-grape, is a North Americanflowering plant.
It is anevergreen shrub with short vertical stems, mostly less than 61 centimetres (24 in),[2] while theleaves reach higher, rarely up to 2.1 m (7 ft) tall on exceptional sites. The plant can reproduce via seeds or byvegetative means, sprouting fromrhizomes which extend laterally through the soil.[3]
The leaves arecompound and oppositelyarranged, with 9–21 leaflets.[2] Each leaflet is up to 7 cm (3 in) long,[2] strongly toothed, reminiscent ofholly, and somewhat shiny, but less so than tallOregon-grape. The leaflets do not have a single central vein as in that species, but several veins arranged fan-like, branched from the leaflet base, hence theepithetnervosa.
Theflowers bloom from early to late spring and are similar to those of other Oregon-grapes, forming small yellow flowers in erect clusters up to 8 inches (20 cm) in length.[3]
Thefruits are dark-blue, globoseberries 7 millimetres (1⁄4 in) in diameter, occurring in clusters[3] and tart-tasting.[4]
Berberis nervosa was scientifically described and named by German-American botanistFrederick Traugott Pursh in 1813.[1][5] In 1818Thomas Nuttall placed it in the new genusMahonia asMahonia nervosa.[1][6] A paper was published byJoseph Edward Laferrière in 1997 summarized the arguments in favor ofBerberis as the correct classification.[7][8] As of 2023 most botanists place the entire genusMahonia within the genusBerberis[9] includingPlants of the World Online (POWO) andWorld Flora Online.[1][10]
It is native to thenorthwest coast of North America from southernBritish Columbia south to centralCalifornia, with an isolated population inland in northernIdaho.[11][12][13] It is especially common in second growth,Douglas-fir[14] orwestern redcedar forests, making use of those pools of sunlight that intermittently reach the ground.
Low Oregon-grape thrives in sun or shade and is a common or dominant species throughout theunderstories in montane, sub-montane, and mixed evergreen forests in the Pacific Northwest. It reaches greatest abundance on relatively dry and warm sites, but occurs in fairly moist environments as well. It grows in a variety of soil types. It is restricted to lower elevations, from sea level to 1,800 m (6,000 ft).[3]
Berberis nervosa can complete its life cycle even in the deep shade of densehemlock-western redcedar forests, so it is aclimax species in old-growth forests where it is often dominant. It also occurs in disturbed sites, usually reaching peak abundance from 4 to 10 years after fire or clearcutting.[3]
Its foliage is browsed byblack-tailed deer andRoosevelt elk in some areas, but is ignored in others. Various small mammals feed on the foliage extensively, and it is extremely important food source for thewhite-footed vole in theCoast Range of Oregon. The fruits are eaten by small birds and mammals, and by black-tailed deer in some areas. The nectar of the genusBerberis is favored by theAnna's hummingbird.[3]
TheYana people dried and ground the fruits to make amush. They can also be dried and eaten like raisins, or used for jelly.[4][15]
SomePlateau Indian tribes drank an infusion of the root to treatrheumatism.[16] Modern medicine uses it against parasites, bacteria, viruses, diabetes, and high cholesterol.[4]
The inner bark is colored yellow by the alkaloid berberine, and was used as a dye by native groups.[4]
The leaves are often used in floral arrangements.[4]
The plant was collected byLewis andClark during theirfamous expedition to the West (before the species' scientific description).[17][4]
