I belong to a Woodland Group which is part of Burton Joyce U3A (University of the Third Age). We were recently carrying out a tree survey in a local wodded area in the village (which is just outside Nottingham). We came across two very young trees which none of the members present could identify at the time. Subsequent research indicates that it is almost certainly Service Trees but we do not know which type. The leaves on the trees were identical to that in the second image down on the NHM page http://www.nhm.ac.uk/nature-online/british-natural-history/urban-tree-survey/identify-trees/tree-factsheets/s-to-y/service/index.html. They have three or four symetrically opposed pairs of basal leaflets below a larger, fused area. The NHM image is
As far as I can see, the site does not identify which specific type of Sorbus this belongs to. From other sites it would appear that the True Service Tree (Sorbus domestica) has leaves that consist only of pairs of leaflets while the Wild Service Tree (Sorbus torminalis) has no leaflets at all. Are our tress a hybrid or another Sorbus species we are not aware of? Alternatively, is it one of the two species named above with a different leaf form because they are so young?
Thanks in anticipation for any information you can provide.