126. Berberis thunbergii Candolle, Syst. Nat. 2: 9. 1821.
日本小檗 ri ben xiao bo
Shrubs, deciduous, compact, usually ca. 1 m tall. Branches angulate, dark red, not verruculose; shoots reddish green, glabrous; spines simple, occasionally 3-fid, 5-15 mm; internodes 1-1.5 cm. Petiole 2-8 mm; leaf blade abaxially grayish green, adaxially green, obovate, spatulate, or rhombic-ovate, 1-2 × 0.5-1.2 cm, thinly papery, abaxially with slightly raised midvein, both surfaces glabrous, with indistinct reticulate veins, base attenuate, cuneate, margin entire, apex mucronate or obtuse. Inflorescence an umbel with subfascicled flowers, (1 or)2-5-flowered, 1-2 cm. Pedicels 5-10 mm, glabrous; bractlets reddish, ovate-lanceolate, ca. 2 mm. Sepals in 2 whorls; outer sepals reddish, ovate-elliptic, 4-4.5 × 2.5-3 mm, apex obtuse; inner sepals broadly elliptic, 5-5.5 × 3.3-3.5 mm, apex obtuse. Petals oblong-obovate, 5.5-6 × 3-4 mm, base clawed, with approximate glands, apex obtusely emarginate. Stamens 3-3.5 mm; anther connective not prolonged, truncate. Ovules 1 or 2, sessile. Berry shiny, red, ellipsoid, ca. 8 × 4 mm, style not persistent; seeds 1 or 2, brown. Fl. Apr-Jun, fr. Jul-Oct.
Commonly cultivated for ornament in China, especially in large cities [native to Japan].
This is one of the most widely cultivated species of Berberis.