Shrubs , self-supporting or clambering, 1-7 m. Leaflets thin and flexible; lateral leaflet blades lance-oblong or elliptic, margins plane or weakly undulate, marginal teeth tipped with spines to 1-1.6 × 0.1-0.2 mm. Inflorescences 6-9 cm.

Flowering winter (Mar). In shade beneath trees, pine and pine-oak forest; of conservation concern; 100-450 m; Calif.

Berberis pinnata subsp. insularis is endemic to the Channel Islands. Specimens of B . pinnata from the coast north of Santa Barbara often show some characteristics of subsp. insularis .