Can you please provide the required photo of the plants the berries came from?
Amerikaanse vogelkers / bospest (Prunus serotina)
Prunus serotina, commonly called black cherry, wild black cherry, rum cherry, or mountain black cherry, is a deciduous tree or shrub belonging to the genus Prunus. The species is widespread and common in North America and South America.
Black cherry is closely related to the chokecherry Prunus virginiana)
The spirit has been met but the required species haven't. Sorry