Ynghylch

Purging buckthorn, sometimes simply called 'Buckthorn', is a small, spiny tree of woodland, scrub and hedgerows on chalky soils. It is widespread, but scarce, across lowland areas of central and eastern England. Clusters of small, yellow-green flowers appear in late spring, and bunches of poisonous, black berries ripen in autumn. Purging buckthorn is the main foodplant of the Brimstone butterfly in the areas where it grows, but Alder buckthorn is used as an alternative.