Berberis thunbergii, the Japanese barberry, Thunberg’s barberry, or red barberry is a species of flowering plant in the barberry family, Berberidaceae, which is native to Japan and Eastern Asia, though widely naturalised in China and North America. Growing to 1 m (3.3 ft.) tall by 2.5 m (8.2 ft.) broad, it is a small deciduous shrub with fruits and green leaves turning brilliant red in autumn, and pale yellow flowers in spring. Numerous cultivars are available as ornamental plants suitable for hedging.

A. Description

• • • Japanese barberry has deeply grooved, brown, spiny branches with a single (occasionally tridentine) spine (actually a highly modified leaf) at each shoot node.
    • The leaves are green to blue-green (reddish or purple in some horticultural variants), very small, spatula to oval shaped, 12 to 24 mm long and 3 to 15 mm broad.
    • They are produced in clusters of 2 to 6 on a dwarf shoot in the axil of each spine. The flowers are pale yellow in colour.
    • 5 to 8 mm diameter, produced in drooping 1 to 1.5 cm long umbrella-shaped clusters of 2 to 5; flowering is from mid-spring to early summer.
    • The edible fruit is a glossy bright red to orange-red, ovoid berry 7 to 10 mm long and 4 to 7 mm broad, containing a single seed.
    • They mature during late summer and fall, and persist through winter.