Viola sororia

This is the violet that often grows in lawns. White or partly-white flowers occur. Some authorities subdivide the species into broad-leaved wood violet (Viola latiuscula), common blue violet (Viola papilionacea), northern blue violet (Viola septentrionalis), and woolly blue violet (Viola sororia). Common blue violet is a variable species. Identifying marks: broad, heart-shaped leaves; flowers and leaves on separate stems that arise from the roots; flowers do not stand much above the leaves (compare to marsh blue violet); and the lowest petal does not have a spur (compare to great-spurred violet).