Preheat oven to 350°.
Lightly spoon 1 cup flour into a dry measuring cup; level with a
knife. Combine 1 cup flour and the next 4 ingredients (1 cup
flour through baking soda), stirring well with a whisk. Place the
granulated sugar and butter in a large bowl, and beat with a
mixer at medium speed until well blended (about 2 minutes).
Add egg and lemon rind; beat until well blended. Add flour
mixture and buttermilk alternately to sugar mixture, beginning
and ending with the flour mixture. Toss blueberries with 1
tablespoon flour, and fold into batter.