- Name also: Common Buckthorn, Purging Buckthorn, European Buckthorn
- Family: Buckthorn Family – Rhamnaceae
- Growing form and height: Shrub or small tree. 2–4 m (7–13 ft.).
- Flower: Regular (actinomorphic), small. Male and female flowers in separate inflorescences. Sepals four, yellowish-green, longer than petals. Petals four, reddish-brown, often membranous. Pistil formed from four fused carpels. Stamens four. Inflorescence a lax cyme, borne in the axils of short shoots.
- Leaves: Leaves (and branches) borne opposite. Stalked, fairly small, hairless. Blade elliptic to ovate, toothed, teeth with a knobble at the tip.
- Buds: With scales, egg-shaped–narrowly cylindrical, dark brown.
- Fruit: Shiny black drupe.
- Habitat: Coppices, wooded rocky slopes and rock outcrops. Also an ornamental. Often on calcareous soils (a calciphile).
- Flowering time: June–July.
Buckthorns are shrubs or smallish trees. The genus comprises more than 100 species most of which are native to East Asia. More than ten are native in Europe, most of them in the Mediterranean countries.
Buckthorn usually grows on calcareous, dry sites. It develops both long and short shoots, and branches often terminate in sharp thorns. Older specimens are often tree-like, dense and thorny, and their trunks are twisted and knobby. Black fruits are poisonous but they have, however, been used as a laxative, at least in Central Europe. Buckthorn also yields dyes: yellow from the bark and, depending on the ripeness, green, yellow, or red from the berries. Wood is hard and contains tannic acids. It has been used in joinery.