Rhamnus cathartica

Common Buckthorn

Tolerates most sites. Dioecious. Very invasive, by the seeds that birds love to eat; probably best to refrain from planting this species in the landscape. Susceptible to rusts (Puccinia coronata), that also attacks oats (in oat growing areas, buckthorn eradication is recommended). The bark, leaves, and fruit were once used in purgatives, thus one of this plant's common names, "Purging Buckthorn".