This is a beautiful 4 stamp sheet, issued by Burundi in 2012, featuring mushrooms and acid rain. Each stamp features images of types of mushrooms, including the False Morel, the Giant Puffball, the Bleeding Tooth Fungus, and the Devil's Cigar. In the background of each stamp is an image of environmental dangers that lead to acid rain. The sheet is Scott catalog.129, and is Post Office fresh, mint never hinged, and F/VF.