Although you can't tell it from the photo "Mrs. R. Barton" is a white violet with violet markings of variable intensity, all on the same plant.  It is named for the wife of the foreman of Windward Violet Nurseries who was a  cook working for the family.  It is a strong grower and a great bloomer with stems sometimes long enough for cutting.  (Windward Violet Nurseries 1930)