Japanese barberry (Berberis thunbergii)
Appearance: Small, compact, spiny shrub, 3-6' tall with slightly curving branches.
Leaves: Small rounded untoothed, arranged in clusters above single spines, appear early in the spring.
Flowers: Yellow, single or in clusters of 2-4 blossoms; blooming in May.
Fruit: Bright red, egg-shaped small berries, in clusters or single, mature in August and stay on the shrub through winter.
Seeds: Dispersed by birds.
Roots: Spreads vegetatively through horizontal lower branches that root freely.