Invasive Species Sheet - Japanese Barberry
Invasive Species Identification Sheet
Japanese Barberry (Berberis thunbergii
-dense shrub with dry, bright red berries remaining after leaves fall
-ridged twigs have slender spines below bundles of leaves
-yellow-colored inner bark on branches and roots.
-flowers yellow, less than 1/2" wide; found along branches; early Spring
-leaves in alternate clusters; entire (have smooth
margins); 1/2" to 1 1/2" long
-fall color is varying shades of yellow, orange, red, purplish
All Barberries in New England are non-native. Japanese Barberry is the
frequently-seen species. It includes many horticultural varieties. The
less-frequent Common Barberry (Berberis vulgaris
L.) is common in Europe. A hybrid between the two has been reported (Berberis
X ottawensis). In the Southeast USA, there is also a native Barberry
(Berberis canadensis [not found in Canada,
nor in New England]) with notched petals and toothed leaves. All these
Berberis species have spiny stems, bright
red berries, and yellow inner bark.
Leaf margins and flower grouping help distinguish among the New England
species. (Unforked spines are typical, but not reliable for distinguishing
Japanese Barberry.) Japanese Barberry has (usually) smooth leaf margins and
flowers growing alone or in umbels (with stems growing from a single point).
Common Barberry flowers are in racemes (branching off a stalk) and the leaf
edges may be bristle-toothed. The hybrid’s flowers resemble an umbel on a stalk.
Leaves may be toothed.
Japanese Barberry typically invades pastures and other open or partly open
areas including open forests, floodplains or wetland edges. It puts on leaves in
the very early Spring and often shades out other plants. After forest logging,
already-present Japanese Barberry bushes may expand into thickets that retard
forest re-growth. Common Barberry also exhibits invasiveness in disturbed