Kingdom:   Plantae
(unranked):        Angiosperms
(unranked):        Eudicots
Order:       Ranunculales
Family:      Berberidaceae
Genus:      Berberis
Species:     B. thunbergii
Binomial name: Berberis thunbergii
Synonyms: Berberis thunbergii var. atropurpurea, Berberis thunbergii var. maximowiczii, Berberis thunbergii var. minor.
Common names: Thunberg's barberry Japanese barberry, Red barberry, Crimson pygmy.

Berberis thunbergii is a species of Berberis, native to Japan and eastern Asia, though now widely naturalised in China and North America, Poland, Finland, Italy, Austria, Denmark, Germany, Netherlands and Australia. In several countries including Australia it now classed as a weed plant.
It is a dense, deciduous, spiny shrub that can grow up to 1.8 m tall. The branches have single or tridentine spines that bear small leaves in their axils.
The small leaves (12–24 mm long and 3–15 mm broad) are smooth-edged and are oval to spatulate in shape and are clustered in tight bunches close to the branches. The shrub’s new leaves are green and in autumn they turn varying shades of orange, red and crimson before falling off.
Yellow/cream flowers bloom mid spring to early summer. They are about 8 mm wide, and are solitary or in small clusters of 2-4 blossoms. 
During mid-summer edible, glossy, bright red to orange-red, ovoid berries (7–10 mm long and 4–7 mm broad) containing a single seed develop. When mature they hang singly or in clusters from the bush during autumn and persist through to spring. Seeds are dispersed by birds and small mammals.

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The new leaves (November)
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Some old dried fruit left on shrub, 
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Shrub covered in berries. No leaves. August.
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Clusters of berries August.
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Leaves have turned red before falling.
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Tridentine spines with small leaves buds in their axils
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