‘Cascara Sagrada’. ‘Cascara Buckthorn’ Perennial. Zones 5-9. Part shade, prefers moist soil. Deciduous tree native through out the Pacific Northwest. Grows 15-35ft tall. Clusters of black berries in summer are loved by birds. Bark is a traditional laxative medicine that was used by indigenous people of the region, now made into a popular herbal supplement.