I should take a pic and request an ID. I've repeatedly passed a similar looking plant, which seems to be wild or feral. Berries are apparently in nearby droppings, which suggest to me that they are not outrightly poisonous.
Luther Burbank's old farm in Sebastopol, California, still has at least 8 old seedling trees that are heavily productive. They consistently produce the largest fruit I have seen on S. Domestica. Lon Rombough had seedlings of them and would occasionally sell seeds of his seedlings but Lon passed away last year.
This weekend I will visit my old hometown, there is an old service tree bearing fruits every year. If someone like I can have a look for some seeds. Can I send it to the US? I read there might be difficulties with custom...
Location: Lueneburg, Northern Germany, Europe Zone 7b
I went on a search of mature true service trees in brittany 2 years ago. I found and visited 10 trees. Below is a picture of fruit from 2 different trees. One small one and the largest-fruited one i found. There is a big difference in fruit sizes. The breton trees are often brown-apple-shaped. The average size of the large fruit was 35mm. The coin in the picture is 26mm and the largest fruit next to the coin was 42mm. (for this picture i picked the largest fruit of a whole bag i collected but average size was only a bit smaller at 35mm)