Alder Buckthorn, Alder-leaf Buckthorn, Alder-leaved Coffeeberry: Rhamnus alnifolia (Synonym: Rhamnus californica var. occidentalis) -
California Buckthorn, California Coffeeberry, Coffeeberry: Rhamnus californica ssp. occidentalis (Synonyms: Frangula californica, Frangula californica ssp. occidentalis, Rhamnus californica var. occidentalis) -
California Buckthorn: Rhamnus californica ssp. tomentella - Non-native.
Common Buckthorn: Rhamnus cathartica - Non-native.
Hollyleaf Redberry, Redberry: Rhamnus ilicifolia (Synonyms: Rhamnus crocea, Rhamnus crocea ssp. ilicifolia) -
Buckthorn, Cascara, Cascara Buckthorn, Chittam, False Buckthorn: Rhamnus purshiana (Synonyms: Frangula purshiana, Frangula purshiana ssp. annonifolia, Frangula purshiana ssp. purshiana) -
Sierra Coffeeberry: Rhamnus rubra (Synonyms: Frangula rubra, Frangula rubra ssp. rubra) -