The Baldwin apple, via USDA
As a child of the Empire State, once home to a wide range of apple varieties, many of them NOT SWEET, America, I salute the efforts of John Bunker of Maine. Bunker is set on saving apple trees, and spreading the seed of as many "mystery" apples as possible, in order to revitalize the reach and range of this remarkable fruit.
From the story in MotherJones: " In the mid-1800s, there were thousands of unique varieties of apples in the United States, some of the most astounding diversity ever developed in a food crop. Then industrial agriculture crushed that world. The apple industry settled on a handful of varieties to promote worldwide, and the rest were forgotten. They became commercially extinct—but not quite biologically extinct."