Of royal empress trees (or "paulownia"), Steve Nix writes that they give "a most dramatic, coarse-textured appearance," but also that they are "now considered an invasive exotic tree species" in the U.S. Bearing large, heart-shaped leaves, royal empress trees display impressive clusters of lavender flowers in the spring. About's Forestry Guide offers much more information on this Chinese native, including pictures, in his article on royal empress trees.