Key to Berberis
View taxon page for Berberis
(For a list of species in Berberis, use the above link.)
Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.
1. Leaves simple
1' Leaves compound3. Bud scales persistent among upper leaves, 15–45 mm, thick, lanceolate; leaflets ± palmately veined ..... B. nervosa3' Bud scales generally deciduous, < 5 mm, thin, ovate to deltate; leaflets generally pinnately veined4. Inflorescence open, flowers generally < 10; petiole generally < 2 cm; terminal leaflets generally lanceolate, oblong, or narrowly elliptic – SW, D
5' Leaflets 3–9, terminal stalked6. Leaflets flat to ± wavy, not folded along midrib, serrate, spines generally > 8 per side, ± 1 mm ..... B. nevinii6' Leaflets wavy, generally folded along midrib, ± lobed, spines generally 3–8 per side, 1–4 mm7. Terminal leaflet generally < 2 × width; berries yellow-red when fresh, ± glaucous, not inflated ..... B. higginsiae7' Terminal leaflet generally > 2 × width; berries blue-black when fresh, heavily glaucous, not inflated or inflated only due to insect parasitism8. Terminal leaflet generally lance-ovate, length generally < 3 × width; flowers 8–12; fruit yellow- to purple-red ..... B. fremontii8' Terminal leaflet generally narrow-lanceolate, length generally > 3 × width; flowers 3–5; fruit red-brown to dark purple ..... B. haematocarpa4' Inflorescence dense, flowers > 10; petiole generally > 2 cm (0–3 cm in Berberis pinnata); terminal leaflets generally ovate to wide-elliptic9. Leaflet margin strongly wavy, thick, generally hard, spines 6–10(12) per side, 2–5 mm ..... B. aquifolium var. dictyota9' Leaflet margin wavy to flat, ± thin, not hard, spines generally > 10 per side (to 0 in Berberis pinnata), 1–2 mm10. Petioles generally > 3 cm; leaflets generally 5–911. Stems ascending to erect, generally 1–2 m; leaflets generally shiny adaxially ..... B. aquifolium var. aquifolium11' Stems spreading to erect, generally < 0.8 m; leaflets generally dull adaxially ..... B. aquifolium var. repens
12. Leaflet margins generally flat, spines generally < 1 mm; upper stems reclining to weakly erect; plant 2–4 m ..... subsp. insularis12' Leaflet margins generally wavy, spines generally > 1 mm; upper stems generally erect; plant generally < 2 m ..... subsp. pinnata