Frangula

Frangula is a genus of about 56 species of flowering shrubs or small trees, commonly known as buckthorn, in the buckthorn family Rhamnaceae. The common name buckthorn is also used to describe species of the closely related genus Rhamnus in the same family, and also the superficially similar but unrelated sea-buckthorn, Hippophae rhamnoides in the Elaeagnaceae.

==Description== Frangula species are deciduous or evergreen shrubs or small trees (to 12 metres tall in F. purshiana) with dark grey-brown to blackish bark; alternate, simple leaves with stipules, buds without bud scales, branches without spines; and flowers with five small petals (cf. usually four in Rhamnus) and undivided styles. The fruit is a two- to four-seeded berry; it is dispersed by birds.