I'm going with the JEPSON and E-FLORA BC designation of just two varieties.
Note: var. nootka has double (one larger than other) toothed leaflets (3-7 per group) found mainly west of the Cascades. Large single flower, stem is sometimes black. Generally two thorns at base of leaf.
north Puget Sound
TRAIL: West Side Road - San Juan Island
HABITAT: Coastal bluff
ELEVATION: 15 meters (55 feet)
BLOOM TIME: 08-JUN