Height: 3′-5′ Spread: 4′-6′. Also called Boulder Raspberry. Rocky Mountain native with large white single flowers in May and June, followed by small dark purple raspberry-like fruit on arching, thornless branches with dark green foliage. Open, vase-shaped growth habit. The cinnamon-brown bark is exfoliating on older stems. May be fuller and denser if older canes are pruned out every few years. Full sun to part shade. Zone 3.