Common buckthorn (Rhamnus cathartica) is an invasive plant. It is a native of Eurasia and was first detected in Indiana in 2002.
Common buckthorn is a shrub or small tree that can grow to 22 feet in height and have a trunk up to 10 inches wide. Buckthorns tend to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them.
For more information about this plant pest, see the CABI data sheet.