Foxglove (Digitalis purpurea) is a non-native plant that puts on quite a show when it's in bloom. Three or four feet high with two-inch purple fingers, it's hard to miss. Though normally a light purple (as the Latin name suggests) it can be rose-colored or even almost white. "Foxglove contains the cardiac glycoside digitoxin, an important heart medecine but deadly in higher concentrations" (Laws Field Guide, p. 143).

These grow in my front and back yard, so you'd think I'd have better pictures, but I don't! Note that Botti says they grow at 1200-1300m, but in fact as I mention, the grow in Yosemite West at 1600-1700m. For California at large, Calflora says these grow anywhere between 0 and 2130m, but that of course includes the entire state.