H&C give 3 varieties:
var. camporum: Leaves are narrow, elongated with few, small sharp teeth. Found mostly ID - MT.
var. debilis: Leaves are shorter, broader, possibly deeply 3-5 lobed. Found mostly e. Cascades.
var. larsenii: Leaves deeply, irregularly 3-7 cleft. Found high elevations, OM and Cascades to N. CA.
Note purple-blue veining in the white petals and the 3-7 cleft succulent hairy leaves.
Found only in talus from broken shards of basaltic glass around 1829m (6,000 ft).
Olympics and Mt. Rainer.