What is the name of one of the native species of buckthorn that is also a powerful plant-based laxative?
Coffee cherry tea:  It is different from cascara sagrada tea, a powerful plant-based laxative. Rhamnus purshiana:  "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.
i don't know