Frangula is a genus of about 35 species of flowering shrubs or small trees, commonly known as alder buckthorn in the buckthorn family Rhamnaceae. The common name buckthorn is also used to describe species of the genus Rhamnus in the same family and also sea-buckthorn, Hippophae rhamnoides in the Elaeagnaceae.

Description

Frangula is a genus of deciduous shrubs with alternate, simple leaves with stipules, buds without bud scales, branches without spines and flowers with five petals and undivided styles. The fruits are 2 to 4-seeded berries. Selected species include: The European species, alder buckthorn (Frangula alnus) was of major military importance in the 15th to 19th centuries, as its wood provided the best quality charcoal for gunpowder manufacture.