Berberis thunbergii

Japanese barberry - This small, thorny shrub is one of the most widespread invasive plants in New England, first seen in the Boston area around 1875. With its brilliant fall foliage and scarlet fruit, it has naturalized in many habitats, including field edges, roadsides, and open forests. Easily identified by the presence of a single spine beneath each cluster of small, untoothed leaves, Japanese barberry is one of the first plants to leaf out in spring. The related common barberry (B. vulgaris) has toothed leaves and a two- or threebranched spine beneath each cluster of leaves. Many forested natural sites, especially in southern New England, have large areas dominated by dense Japanese barberry stands beneath which nothing but barberry seedlings can grow. [image: (c) Leslie Mehrhoff]

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