Paulownia is a very fast growing tree and you sometimes see ads in newspaper inserts touting it as a super-fast growing shade tree. And among trees, the princess tree is a real speed demon, growing to several inches diameter in just a few years, but this also means its wood is light weight and the trees tend to break easily and die young. So why was it imported way back in 1834? Well, in flower the princess tree is quite striking with its big panicles of large snapdragon like flowers.
And it makes lots of seeds, and they grow quite well in disturbed areas. The fact that princess tree is a woody invasive "weed" in some areas is not actually much of a problem there in the NYC area because where it grows, on railroad embankments, vacant lots, alleys, and the like ,means it covers up even worse looking stuff. However in areas of eastern TN and western NC this invasive tree is taking over road sides and rocky areas, and it has become so common many people think it a native. While the tree looks quite a bit like a Catalpa, it isn't a member of the bignon family, but sort of loosely related to some of the bits and pieces left over from the recent dismemberment of the snapdragon family.
So royalty or just a royal pain? Mostly the latter except when its flowering.