Ask any American Robin and they'll tell you that August is wild cherry time in New England. The largest cherry, and the only variety with fruit often well above human reach, is Black Cherry (Prunus serotina). If you find reachable cherries on small trees or on large trees with low branches, you can tell the dark purple-black fruits are ripe when they detach easily from their short stalks.
The flavor of Black Cherries can sometimes rival that of sweet, cultivated varieties, but at other times these fruits are disagreeable and best left for the birds. It's wise to sample each tree's fruit before gathering a bucketful. The leaves of Black Cherry are narrow and bluntly toothed. Leaf undersides usually have noticeable hairs along the midrib. Bruised twigs are strongly almond-scented.
When tasty fruit is found in quantity, Black Cherries can be gathered and processed into fruit leathers, jams and juices. The only trick is removing the pits* – a job that can be done by hand (if you don't mind purple fingers) or with the help of various food mills. Or, you can simply eat them out of hand, spitting out the pits as you go.
*Note: In their raw state, Black Cherry pits contain a carbohydrate called prunasin that is broken down in the body into various compounds, including hydrocyanic acid, which is harmful to humans in sufficient quantity. The flesh alone is perfectly safe.