Berberis nervosa

Oregon-grape

Berberidaceae

The Basics

Taxonomy: Kingdom - Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (Flowering plants). Class - Magnoliopsida (Dicotyledons). Subclass - Magnoliidae. Order - Ranunculales. Family - Berberidaceae (Barberry familly). Genus -Berberis Nutt. . Species - Berberis nervosa (Pursh) Nutt. - Cascade barberry.

Ecology: A shade-tolerant/intolerant, submontane to montane, Pacific North American evergreen shrub. Occurs in maritime to submaritime cool mesothermal climates on moderately dry to fresh, nitrogen-medium soils; its occurrence decreases with increasing precipitation, elevation, and continentality. Scatered to abundant, occasion­ally dominant, in the understory of semi-open forests (persists on cutover sites) on water-shedding sites. Inhabits coarse-skeletal soils. Commonly associated with Gaultheria shallon, Kindbergia oregana, and Polystichum munitum. Characteristic of mesothermal forests. In and west of the Cascades, southern British olumbia to central California. Open woods, sea level to moderate elevations in the mountains. Cascade barberry persists in closed forest stands with long fire-free intervals.

Identification

General: Strongly rhizomatous evergreen shrub, the aerial stems 1-3 dm. long, ascending to erect.

Leaves: Leaves alternate, pinnate, tufted, leathery; leaflets 9-19, ovate-lanceolate, 3-6 cm. long, coarsely serrate-spiny, palmately 3-8 nerved, both surfaces somewhat dull.

Flowers: Inflorescence of bracteate racemes up to 20 cm. long; perianth of 5 alternating whorls of 3 members each; outer 3 greenish-yellow, 2-3 mm. long (bracts); next 6 bright yellow, 6-8 mm. long (sepals); inner 6 bright yellow, slightly shorter, bi-lobed, oblong (petals); stamens 6, opposite the petals; filaments without teeth at the tip; style none, stigma sessile.

Fruits: Berry deep blue, globose, 8-11 mm. long.

Threats

Berberis nervosa is resistant to infection by Puccinia graminis.

Cascade barberry commonly sprouts and grows vigorously after fire. Reestablishment through seed may occur, although vegetative regeneration is the dominant mode of postfire establishment. Cascade barberry persists in closed forest stands with long fire-free intervals.  However, as a residual survivor, it is also well-adapted to a regime of "relatively frequent surface fires" such as those common in certain Douglas-fir-western hemlock/Cascade barberry types of Oregon.  Fire intervals in Douglas-fir-western hemlock forest inhabited by Cascade barberry commonly range from 137 to 320 years. 

Reproduction

Seed Production - Seed of most Oregon-grapes exhibit internal dormancy and require cold stratification for germination. Under natural conditions, seeds of most species within the genus germinate during the spring.

Vegetative Reproduction -Cascade barberry is rhizomatous and gradually expands laterally in the absence of disturbance.Plants generally sprout from rhizomes or "creeping rootstocks" after aboveground portions of the plant are destroyed. Vegetative regeneration appears to be the dominant mode of regeneration after fire or other disturbances

Species Distribution

Citation

E-Flora of British Columbia
Brian. (Editor) 2015. E-Flora BC: Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 30/01/2017 10:54:05 AM ]

USDA Plants Database
USDA, NRCS. 2017. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
Distribution Map photo credit

USFS Plant Database
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).

Flora of North America
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 19+ vols. New York and Oxford.

Burke Museum of Natural History and Culture
Burke Museum. 2017. Berberis nervosa [Online]. University of Washington.
Photo credit: Bud Kovalchik, Clayton J. Antieau,2016, Brian Luther.