Frangula alnus, also known as the spruce tree or dirt tree, is a native shrub or small tree found in Europe, Asia and North America. This shrub is known for its smooth grey bark and glossy green leaves, which often turn yellow or red in autumn before falling off.

The small flowers appear in spring, followed by small, black berries in autumn. Although the berries are poisonous to humans, they are an important food source for birds and other animals. Frangula alnus does well in moist soil and is often found in marshes or along stream valleys.