It’s the time of the vendemmia or grape harvest, and in all the markets now you can find this irresistibly, seductive fruit. A pulp, sweet at first, sour if you bite into it, which pops out of a rather thick tart skin. Delicious, addictive. Nature’s “SweeTart.” This is the Uva Americana or “American Grape,” also known in Italy as Uva Fragola or “Fragolino” because of its strawberry overtones. This vine originating in North America survives well in Italy’s northern climes. And thank God it does, because it is one of September’s greatest sensual pleasures. If the taste doesn’t overwhelm your senses, its appearance will. Deep purple, the color of sensuality itself, dusted with what appears to be a permanent morning mist. Don’t be shy when buying them. A large “vaschetta” (or little tubful) will disappear before you know it.