http://www.durgan.org/ShortURL/?VEQRG 7 August 2008 Showy mountain-ash (Sorbus decora) New Pictures to compare to: http://www.tcf-fca.ca/trees/species_...id=273&lang=en
I thought it might be S. decora when you showed your tree earlier and also thought I had suggested as much. S. americana seen here not the same introduction as the 'Dwarfcrown' cultivar nevertheless resemble it. Some sources still call it S. tianshanica 'Dwarfcrown'. The narrow, upright crowns and long pointy leaves of these are not much like those of your tree.
