Burke: Berberis nervosa vs. Berberis thunbergii

	Berberis nervosa	Berberis thunbergii
		Japanese barberry
Habit	Low, evergreen shrubs generally 0.1-0.3 m, occasionally taller; glabrous, brown to yellow-brown bark.	Deciduous shrubs 0.3-3 m. tall, the stems dimorphic, with elongate primary and short axillary shoots; second year bark glabrous, purple to brown; stems spiny.
Leaves		Leaves simple; petioles 0-0.8 cm. long; leaf blades obovate to spatulate, 1-veined from the base, 1.2-2.4 cm. long and 0.3-1 cm. wide, thin and flexible, the base tapered, the margins plane and entire, the tip rounded; surfaces smooth and dull.
Flowers		Inflorescence a 1- to 5-flowered umbel, 1-1.5 cm. long; flowers yellow, with 6 sepals, 6 petals, and 3 membranous, scale-like bracteoles; stamens 6.
Fruits		Berries red, ellipsoid or spheric, 9-10 mm. in diameter, juicy and solid
Leaves	Leaves alternate, pinnately-compound, leathery; leaflets 9-21, glossy to somewhat dull and glaucous, lance-ovate to ovate, 3-8 cm long and 1-5 cm broad, 4-6 veins from base, somewhat dull and glaucous, 6-13 spine-tipped teeth.
Flowers	Inflorescences dense racemes, 6-17 cm long with 30-70 flowers; bracts 3, greenish-yellow, 2-3 mm long; sepals 6, yellow, 6-8 mm long; petals 6, yellow, bi-lobed; stamens 6, opposite of petals; pair of lateral teeth absent from filaments; style none, stigma sessile.
Fruits	Berries blue, glaucous, juicy, solid, oblong-ovoid to globose, 8-11 mm.

	Berberis nervosa	Berberis thunbergii
Flowering time	April-May	April-May
Habitat	Generally in light woodland and forest edge.	Disturbed areas
Distribution	Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to western Montana. [WildflowerSearch map]	Sparingly introduced in Washington; escaped throughout central and eastern United States and Canada. [WildflowerSearch map] [BONAP county map]
Origin	Native	Introduced
Conservation status	Not of concern	Not of concern
Sibling taxa	B. darwinii, B. julianae, B. thunbergii, B. vulgaris	B. darwinii, B. julianae, B. vulgaris
Web links	Local floras: BC, CA, OR Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Berberis nervosa

Berberis thunbergii

Japanese barberry

Habit

Low, evergreen shrubs generally 0.1-0.3 m, occasionally taller; glabrous, brown to yellow-brown bark.

Deciduous shrubs 0.3-3 m. tall, the stems dimorphic, with elongate primary and short axillary shoots; second year bark glabrous, purple to brown; stems spiny.

Leaves

Leaves simple;

petioles 0-0.8 cm. long;

leaf blades obovate to spatulate, 1-veined from the base, 1.2-2.4 cm. long and 0.3-1 cm. wide, thin and flexible, the base tapered, the margins plane and entire, the tip rounded;

surfaces smooth and dull.

Flowers

Inflorescence a 1- to 5-flowered umbel, 1-1.5 cm. long;

flowers yellow, with 6 sepals, 6 petals, and 3 membranous, scale-like bracteoles;

stamens 6.

Fruits

Berries red, ellipsoid or spheric, 9-10 mm. in diameter, juicy and solid

Leaves

Leaves alternate, pinnately-compound, leathery;

leaflets 9-21, glossy to somewhat dull and glaucous, lance-ovate to ovate, 3-8 cm long and 1-5 cm broad, 4-6 veins from base, somewhat dull and glaucous, 6-13 spine-tipped teeth.

Flowers

Inflorescences dense racemes, 6-17 cm long with 30-70 flowers;

bracts 3, greenish-yellow, 2-3 mm long;

sepals 6, yellow, 6-8 mm long;

petals 6, yellow, bi-lobed;

stamens 6, opposite of petals; pair of lateral teeth absent from filaments;

style none, stigma sessile.

Fruits

Berries blue, glaucous, juicy, solid, oblong-ovoid to globose, 8-11 mm.