Blackberries are just coming into season. One of the most flavorful is the dewberry, an early-season species that trails the ground.
We may also get the first elderberries of the summer. They're not sweet, and they must be cooked, but they're great, sweetened, in pancakes, muffins, and breads.
Black cherries will also be in season. These native bittersweet fruits, with the flavors of cherry and grapefruit, are great raw, and superb cooked with a thickener and sweetener in all the standard puréed fruit desserts.
Another great native fruit we could find is the mayapple. Poisonous when green and unripe, the ripe, yellow fruit tastes like lemon custard.