I have at last discovered that the mystery tree in our front yard is a Schubert Chokecherry, also known as Canada Red Cherry. Steve had deemed it a cherry tree in the spring when it filled with white blossoms, but the fruit turns out to be less than a half inch in diameter and doesn’t taste sweet as it ripens. (I was a little worried about tasting it, but how else can one use flavor to identify? Chokecherry fruit is supposed to taste astringent, and indeed it puts the pucker reflex in gear.)
One identifying characteristic is that the leaves turn reddish purple in summer. I had a hard time finding a cherry tree that does this. Local wild chokecherry doesn’t have that characteristic. God bless the Internet and Google image search. That did the trick.
We also used the taste test on Twinberries when we were on the strawberry river. They look beautiful and taste awful. The books say they’re poisonous, but not to worry, no one in his right mind would eat enough to actually be harmed by them.