Rhamnus purshiana
（重定向自Cascara Buckthorn）
![](/Images/godic/202501/03/Rhamnus_purshiana_-_Köhler–s_Medizinal-Pflanzen-1210709.jpg")
![](/Images/godic/202501/03/Rhamnus_purshiana_range_map0709.png")
![Branch of a cascara tree. Note the prominently veined, alternate leaves, the reddish twigs, and the clusters of flowers at the leaf axils.](/Images/godic/202501/03/Rhamnus_purshiana,_Cascara_--_branch_with_leaves,_flowers_and_buds0709.JPG")
![Leaves, flower, and young fruits of R. purshiana](/Images/godic/202501/03/Rhamnus_purshiana_--_leaves_and_fruits0709.JPG")
Rhamnus purshiana (cascara buckthorn, cascara, bearberry, and in the Chinook Jargon, chittem and chitticum; syn. Frangula purshiana, Rhamnus purshianus) is a species of buckthorn native to western North America from southern British Columbia south to central California, and eastward to northwestern Montana.