any of various thorny shrubs of the genus Pyracantha bearing small white flowers followed by hard red or orange-red berries

Firethorn (Pyracantha) is a genus of thorny evergreen large shrubs in the family Rosaceae, subfamily Maloideae. They are native from southeast Europe east to southeast Asia, and are closely related to Cotoneaster, but have serrated leaf margins and numerous thorns (Cotoneaster is thornless).