Canada Mayflower [Maianthemum canadense] found near the Blue Ridge Parkway, milepost 437, Glassy Mine Overlook, along the Mountains-to-Sea Trail, on 30 May 2015. It’s a member of the Lily (Liliaceae) family. Newcomb’s Wildflower Guide, pages 130-131, says its flowers bloom in spring. It’s also named Wild Lily-of-the-valley.
USDA Plants Listing: Maianthemum canadense