Snowbird Hawthorn (Crataegus x mordenensis ‘Snowbird’):  Smaller tree with dark green, glossy leaves and double white flowers in spring followed by bright crimson haws in fall.  Attracts birds.  Height: 5 m; Width: 4 m. Full sun to partial shade. Zone 3

Photo Credits:
Paul Wray, Iowa State University, Bugwood.org