Mahonia aquifolium
English: Oregon grape; Oregon grape-holly; Oregon holly-grape.
Name: aquifolium means sharp-leafed.
Region: western North American West, Southeast Alaska to Northern California, Alberta to central New Mexico.
Habitat: in the understory of Douglas fir forests, in brushlands; resistant to summer drought, tolerates poor soils, and does not create excessive leaf litter.
Content: alkaloids; berberine.5'-methoxyhydnocarpin (5'-MHC), a multidrug resistance pump inhibitor, which works to decrease bacterial resistance in vitro.
Culture: Oregon-grape is the state flower of Oregon.
Use: ornamental, in shady or woodland plantings, for its striking foliage and flowers; fruits and seeds for food with salal or another sweeter fruit; inner bark yields a yellow dye; berries give purple dye.
Botany
Shrub; evergreen; 1 to 3 m tall, 1.5 m wide.
Stems: thickened, corky appearance.
Leaves: pinnate, spiny, resembling Ilex; leathery; consisting of spiny leaflets; up to 30 cm long.
Inflorescence: dense clusters; raceme; 3 to 8 cm long.
Flowers: yellow; sepals 6, bright yellow; petals 6, bright yellow; stamens 6, opposite the petals, terminating in two spreading branches; bracts 3, greenish-yellow, at the base of the flower; blooming in early spring.
Pollination: by Bombus species and other insects.
Fruit: dark bluish-black berries; quite tart; contain large seeds.
Dispersion: by birds.
Taxonomy
Some authors place Mahonia in the barberry genus, Berberis.