Rhamnus purshiana

Cascara is a dark green bush or semi-deciduous tree that grows from northern California to British Columbia to Montana. This buckthorn grows under heavy chaparral or forest conditions, north slope. Mixed with Douglas fir, red alder, red cedar, hemlock, vine maples, and Oregon Crab. Cascara looks like an Alder crossed with a Birch, with a cherry thrown in. Rhamnus purshiana is supposed to be deciduous, but is is not very deciduous in mild winters. It may be evergreen in much of California. In our nasty winters it still has leaves. (Rhamnus purshiana synonym Frangula purshiana, Rhamnus anonaefolia, R. purshianus))