Mahonia aquifolium or Oregon grape) is a species of flowering plant in the family Berberidaceae, native to western North America. It is an evergreen shrub growing to 1 m (3 ft) tall by 1.5 m (5 ft) wide, with pinnate leaves consisting of spiny leaflets, and dense clusters of yellow flowers in early spring, followed by dark bluish-black berries.
M. aquifolium grows to 1–2 m (3 ft 3 in–6 ft 7 in) tall by 1.5 m (5 ft) wide, with pinnate leaves up to 30 cm (12 in) long, each leaf made up of spiny leaflets.
The leathery leaves resemble holly and the stems and twigs have a thickened, corky appearance. The flowers, borne in dense clusters in late spring, are yellow, and are followed by spherical dark dusty blue berries, which give rise to the common name "Oregon grape".