Unknown deciduous tree growing in Portland. Oregon. Now 18" caliper, 40'+ ht.x30'+ spread. Strongly ridged bark, charcoal gray color. Looks almost like a walnut at first glance, but leaves are bi-pinnately compound, almost fern-like, serrated much like Rhus typhina 'Lanciolata' with a deep, strong V-shaped petiole. Leaves are 16"+ long, 20+ leaflets with a terminal leaflet. Leaflets dark green with prominent yellow-green center vein. Looks nothing at all like any pinnately compound-leaved North American trees that I've ever seen before. (Unfortunately I don't have any good plant keys for Asiatic tree species.) Any ideas?