SB-black birch, sweet birch, cherry birch, all the same tree (Betula lenta). I think most wintergreen is made synthetically now, but at one time there were distilleries here in the western NC mountains that processed wintergreen oil extracted from birch trees. there was a cottage industry here collecting the stuff. Methyl salicylate, or oil of wintergreen, is also found in the wintergreen plant (Gaultheria), and was also extracted from it. Birch beer was also a traditional thing here-people tapped the sweet birches just like you would a sugar maple and collected the sap to ferment.