10. Berberis higginsiae Munz, Aliso. 4: 91. 1958.
Mahonia higginsiae (Munz) Ahrendt
Shrubs , evergreen, 1-3 m. Stems ± dimorphic, with elongate primary and short or somewhat elongate axillary shoots. Bark of 2d-year stems brown or purple, glabrous. Bud scales 2-3 mm, deciduous. Spines absent. Leaves 5-7-foliolate (or 3 by abortion of basal pair, leaving prominent articulation on petiole); petioles 0.1-0.4 cm. Leaflet blades thick and rigid; surfaces abaxially dull, papillose, adaxially dull, glaucous; terminal leaflet stalked (sessile in a few leaves), blade 1.4-3.4 × 1.1-2.4 cm, 1-2.5 times as long as wide; lateral leaflet blades oblong to ovate or elliptic, 1-3-veined from base, base obtuse or truncate, margins undulate or crispate, toothed, each with 2-5 teeth 1-4 mm high tipped with spines to 1.2-3 × 0.2-0.3 mm, apex rounded to acute. Inflorescences racemose, lax, 5-8-flowered, 2.5-8 cm; bracteoles membranous, apex acuminate. Berries yellowish red, slightly glaucous, spheric, 6-8 mm, juicy, solid.
Flowering spring (Apr-Jun). Chaparral and pinyon-juniper woodland; of conservation concern; 800-1200 m; Calif.; Mexico (Baja California).
Berberis higginsiae is endemic to the region immediately south and east of San Diego, California. The leaflet description above fits the few known California collections; specimens with narrower leaflets (terminal leaflets to 4.5 times as long as wide) have been collected just south of the Mexican border, where leaflet shape may be variable on a single specimen. Berberis higginsiae is intermediate between B . fremontii and B . haematocarpa in its variable leaflet shape and berries that are small and juicy but yellowish red. Further study may show that it is conspecific with one of these species (R. V. Moran 1982).
Berberis higginsiae is susceptible to infection by Puccinia graminis .