Frangula alnus, commonly known as glossy buckthorn, is a shrub that can grow to seven metres and is sometimes considered a tree. Frangula alnus typically inhabits wet, shaded and acidic soils. It can grow in soils of any texture. In North America, wetlands are invaded by Frangula alnus. Frangula alnus is also a typical woody pioneer during the succession of drained mires and conveyed wet meadows, being overgrown and substituted by forest vegetation. The invasion of Frangula alnus into forests and riparian areas in the North American region has alarmed foresters and conservationists. Frangula alnus attains high cover in the understorey and tree seedling density and diversity is known to be inversely related to buckthorn basal area. Frangula alnus can also out-compete and exclude native woody species.