How about the Ailanthus tree? I've also heard it called the "tree of Paradise," or the "tree of Heaven." This exotic tree was imported (from China?) to support the silkworm industry and is now one of the biggest weed trees around. I've seen them flourishing in very urban neighborhoods (not necessarily smoggy, but...). I believe the ailanthus was the subject of A TREE GROWS IN BROOKLYN. Good luck, Marty Perdue [log in to unmask] (I am not a botanist and this is not a scientific observation). :)