20.
Berberis pinnata
Lagasca, Elench. Pl. 14. 1816.
Mahonia pinnata
(Lagasca) Fedde
Shrubs , evergreen, 0.3-1.6(-7) m. Stems usually monomorphic, seldom with short axillary shoots. Bark of 2d-year stems grayish brown, glabrous. Bud scales 3-7 mm, deciduous. Spines absent. Leaves (3-)5-13-foliolate; petioles 0.5-4.5(-7.5) cm. Leaflet blades thin and ± rigid or flexible; surfaces abaxially glossy, smooth, adaxially glossy, green; terminal leaflet stalked, blade 2.6-6.2 × 2-4.5 cm, 1.3-1.9 times as long as wide; lateral leaflet blades elliptic to ovate or broadly lanceolate, 1(-3)-veined from base, base broadly obtuse, truncate, or weakly cordate, margins plane to crispate, toothed, each with 5-22 teeth 0-2 mm tipped with spines to 1-3 × 0.1-0.3 mm, apex acute to rounded-obtuse. Inflorescences racemose, dense, 25-50-flowered, 2-9 cm; bracteoles membranous, apex rounded to broadly acute, sometimes apiculate. Anther filaments with distal pair of recurved lateral teeth. Berries blue, glaucous, oblong-ovoid to subspheric, 6-7 mm, juicy, solid.
Berberis pinnata is very similar to B . aquifolium , and the two are sometimes difficult to separate. Some authors have used the spacing of the lateral leaflets (said to be contiguous or imbricate in B . pinnata and remote in B . aquifolium ) to separate them, but the leaflets are often remote in both species and may be contiguous in B . aquifolium .
Berberis pinnata is resistant to infection by Puccinia graminis .
