Skip

Invasive Species Sheet - Common Buckthorn

Invasive Species Identification Sheet

Common Buckthorn (Rhamnus cathartica L.)

Alternate common name: European Buckthorn, which is also a common name of the invasive, non-native Glossy Buckthorn (Frangula alnus Mill.)
- shrub or small tree on which the bark has lenticels (raised corky areas)
- branchlets end in small thorns that come out between the last pair of buds
- leaves opposite, (some may be somewhat alternate); 1"-2 1/2" long; not hairy
- leaf margins with small, but clearly seen, teeth; most leaf tips come to a sudden point
- leaves with 3-4 veins (sometimes 2) on each side of the leaf midrib; leaf stems grooved
- leaf veins curve up to follow the leaf edges and stand out on the leaf underside
- tiny flowers each have 4 whitish or greenish petals; flowers grow out of leaf axils
- fruit a drupe (berry-like), ripening to black in late summer; persists well into winter
- seeds 3-4 (if all develop properly)
- seeds deeply and narrowly grooved on outer surface; raised on inner surface
- young branchlets are not hairy
- inner bark yellow

Common Buckthorn holds its leaves late into the Fall. The deciduous leaves change to a light green or yellow color
that stands out in the forest understory. Although Common Buckthorn prefers neutral or calcium-rich soils, it
thrives in open or partially-open habitats on a wide variety of soils. It may create dense thickets.

In contrast to Common Buckthorn, Alderleaf Buckthorn (Rhamnus alnifolia L’Her.), a native shrub, has
toothed, but alternate, leaves with 8-9 pairs of veins. The leaf surface is puckered (like seer-sucker fabric). The
buds are scaly, but the branchlets lack thorn tips.