Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x5-inch loaf pan.
In a medium bowl, toss blueberries in 2 tablespoons flour. Gently stir blueberries together with oats, nuts, 1 1/2 cups flour, baking soda, and salt.
In a large bowl, cream shortening. Gradually add sugar, beating until light and fluffy. Add eggs one at a time, beating well after each addition. Stir in mashed banana. Add blueberry mixture to creamed mixture, and stir just until moistened. Spoon batter into the prepared pan.
Bake in preheated oven until a wooden toothpick comes out clean when inserted in the center of the loaf, 50 to 55 minutes. Cool in pan for 10 minutes. Remove from pan, and cool completely on a wire rack.