Thanks for the follow up pic but I beleve we have a misunderstanding on a leaf vs. leaflet. This plant has compound leaves composed of leaflets. It appears from the last pic that the leaves are compound even (2 leaflets at the end of the compound leaf). I initially thought that this was a sumac but the leaflets are entire and lance shaped (poison sumac has elliptical) and the leaves are apparently compound even, thus this is not a Rhus that I am familar with. Growin's other suggestion, Pistacia chinensis, is likely your plant.