Page authors: Don Knoke, David Giblin
Mahonia nervosa
Cascade Oregon-grape, dull Oregongrape
WTU specimens
Other herbaria

Distribution: Occurring on both sides of the Cascades crest in Washington; southern British Columbia to California, also in northern Idaho.

Habitat: Open woods, sea level to moderate elevations in the mountains.

Flowers: March-June

Origin: Native

Conservation Status: Not of concern


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


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.


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.


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

Accepted Name:
Mahonia nervosa (Pursh) Nutt.

Synonyms & Misapplications:
Berberis nervosa Pursh [FNA3, HC, HC2]
Berberis nervosa Pursh var. mendocinensis Roof
Mahonia nervosa (Pursh) Nutt. var. mendocinensis (Roof) Roof
Odostemon nervosus (Pursh) Rydb.
Additional Resources:

PNW Herbaria: Specimen records of Mahonia nervosa in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Mahonia nervosa checklist entry.

E-Flora BC: Mahonia nervosa atlas page.

CalPhotos: Mahonia nervosa photos.

USDA Plants: Mahonia nervosa information.

43 photographs:
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