The London Plantetree is a hybrid of the American Sycamore from eastern North America x the Oriental Sycamore from southeast Europe and western Asia. It differs from the American Sycamore in having smaller, deeper lobed leaves and having the buttonball fruits hanging in 2's on the twigs rather than singly. (I like the leaves being smaller as it looks better to me with less course texture.) It also is more resistant to the sycamore leaf anthracnose disease that causes the American species to lose its first crop of leaves in spring and some twig damage before producing a second crop of leaves during drier, warmer conditions. Cool, wet springs encourage the fungus. Otherwise, there is no great difference. A good number of larger conventional nurseries sell this hybrid species. Oftentimes, they will also sell the American species. Of the planted trees, I would say that still more American trees are planted in the Midwest, the South, the Mid-Atlantic, and the Northeast USA than the hybrid.