''Mahonia nervosa'', commonly known as dwarf Oregon-grape, Cascade barberry, Cascade Oregon-grape, or dull Oregon-grape, is a

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

native to the northwest coast of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

from southern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

south to central

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, with an isolated population inland in northern

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

. It is especially common in second growth, Douglas-fir or western redcedar forests, making use of those pools of sunlight that intermittently reach the ground. Some authors place the entire genus ''Mahonia'' within the genus '' Berberis''. The plant was collected by Lewis and

Clark Clark is an English language surname, ultimately derived from the Latin with historical links to England, Scotland, and Ireland ''clericus'' meaning "scribe", "secretary" or a scholar within a religious order, referring to someone who was educate ...

during their famous expedition to the West before being described for science by Frederick T. Pursh in 1813.''Fl. Amer. Sept.'' (Pursh) 219. 1814 ec. 1813 Collectors: M.Lewis, W.Clark s.n.

Description

It is an

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

with short vertical stems, mostly less than , while the leaves reach higher, rarely up to tall on exceptional sites. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are compound and of opposite arrangement, with 9–19 leaflets; each leaflet is strongly toothed, reminiscent of holly, and somewhat shiny, but less so than tall Oregon-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 the

epithet An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...

''nervosa''. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s bloom from early to late spring and are similar to those of other Oregon-grapes, forming small yellow flowers in erect clusters up to in length. Like other species in the genus ''Mahonia,'' the

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

are dark-blue, globose berries of in diameter which occur in clusters and are tart-tasting.

Ecology

Low Oregon-grape thrives in sun or shade and is a common or dominant species throughout the understories 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 . ''Mahonia nervosa'' can complete its life cycle even in the deep shade of dense hemlock- western redcedar forests, so it is a climax 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. The plant can reproduce via seeds or by vegetative means, sprouting from

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

s which extend laterally through the soil. Its foliage is browsed by black-tailed deer and Roosevelt 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 the

white-footed vole The white-footed vole (''Arborimus albipes'') is a species of rodent in the family Cricetidae. It is found only in the United States. Its natural habitat is temperate forest A forest is an area of land dominated by trees. Hundreds of def ...

in the Coast Range of Oregon. The fruits are eaten by small birds and mammals, and by black-tailed deer in some areas. The nectar of the genus ''Mahonia'' is favored by the

Anna's hummingbird Anna's hummingbird (''Calypte anna'') is a medium-sized bird species of the family Trochilidae. It was named after Anna Masséna, Duchess of Rivoli. It is native to western coastal regions of North America. In the early 20th century, Anna's hu ...

Uses

Some

Plateau Indian Indigenous peoples of the Northwest Plateau, also referred to by the phrase Indigenous peoples of the Plateau, and historically called the Plateau Indians (though comprising many groups) are indigenous peoples of the Interior of British Columbia ...

tribes drank an infusion of the root to treat

rheumatism Rheumatism or rheumatic disorders are conditions causing chronic, often intermittent pain affecting the joints or connective tissue. Rheumatism does not designate any specific disorder, but covers at least 200 different conditions, including art ...

. Modern medicine uses it against parasites, bacteria, viruses, diabetes, and high cholesterol. The Yana people dried and ground the fruits to make a

mush In multiplayer online games, a MUSH (a backronymed variation on MUD most often expanded as Multi-User Shared Hallucination, though Multi-User Shared Hack, Habitat, and Holodeck are also observed) is a text-based online social medium to which mult ...

. They can also be dried and eaten like raisins, or used for jelly. The inner bark is colored yellow by the alkaloid berberine, and was used as a dye by native groups. The leaves are often used in floral arrangements.

References

External links

Flora of North America (as ''Berberis nervosa'')Jepson Flora Project (as ''Berberis nervosa'')
{{Taxonbar, from=Q647429

nervosa ''Nervosa'' is an album by the band Showbread. It was released on May 13, 2008, simultaneously with its companion album ''Anorexia''. Nervosa second in a two-CD collection entitled Anorexia Nervosa, which is an accompaniment to the short story '' ...

Flora of the Northwestern United States Flora of British Columbia Flora of California Flora of the Klamath Mountains Natural history of the California Coast Ranges Plants described in 1813 Plants used in traditional Native American medicine Garden plants of North America Bird food plants Flora without expected TNC conservation status