Purging Buckthorn Rhamnus cathartica

The Purging Buckthorn is a shrub or small tree, native to Britain, that grows well on chalk soils. It is not easy to see when growing in hedges, but is more easy to identify when growing on scrub land or open hillsides. The bark and fruit were once used as a powerful purgative. It is the food plant (along with Alder Buckthorn) of the Brimstone butterfly. It is a member of the Buckthorn family in which the leaf veins all curve towards the tip.

 Buckthorn tree on a chalk hillside in May.

Usually seen as a shrub – photo in July.

The leaf is finely-toothed. The veins curve round to the tip.  


The thorns are long, like a Blackthorn.

Male and female flowers are on different trees.Close-up of a tiny female flower, showing the 4 petals and 4 styles and stigmas in late May.

Fruit in July. The fruit looks like a berry but technically is a drupe with two to four stones enclosed by a fleshy layer

Fruit at the end of September. The ‘berries’ are eaten by birds and the seeds distributed in their dropping. The ‘berries’ have a powerful purgative effect when eaten by humans, hence the latin name cathartica.

The bark is banded and scaly.