Combine first six ingredients. Grate in butter, occasionally tossing with some of the flour mixture.
Add buttermilk and poppyseeds and stir just until moistened.
Turn dough out on lightly floured surface; pat into an 8 inch circle. Cut circle into 8 wedges using a bench knife.
Place 1 inch apart on parchment paper lined baking sheet.
Bake at 425 degrees for 15 minutes or until golden.
While scones are baking, juice one lemon and add powdered sugar to make a thin glaze.
Glaze scones after removing from oven.
Notes
Dry ingredients and butter can be combined ahead of time and stored in the refrigerator. Poppyseeds and buttermilk can be added right before placing in the oven.