This is an escape from gardens or orchards. However these fruit trees are much hybridised and so this is likely to be some variety or other. Prunus ssp are difficult to identify from even a combination of twigs (hairy or not) and flowers so even but with ripe yet green fruit this must be a Greengage of some kind.

Prunus domestica ssp italica is dotted here and there in England mostly in the south but there is little in Wales, Scotland or Ireland.

Mudchute park, London, 1st July 2006

Added on 15th February 2007, updated 28th July 2011