This is a beautiful sheet of 4 stamps, issued by Guinea-Bissau in 2001, honoring Scottish biologist and pharmacologist Sir Alexander Fleming. Also featured on the stamps are the Orange Birch Bolete Mushroom, The Weeping Bolete Mushroom, Porcini Mushroom, and the Russula Paludosa Mushroom. The sheet is Post Office fresh, mint never hinged, and F/VF.