I thought it worthwhile to mention that in Britain and Ireland, 'Sycamore' is not the Plane tree, but Acer pseudoplantanus. This tree seeds about and is far more common than any Platanus. It is common in hedgerows, etc, but is not usually deemed to be a good landscape tree due to it's tendancy to seed and its being prone to tar spot fungus which causes early defoliation.
How interesting. And how awful those spots look!
Yup no wonder some people get confused with Acer pseudoplatanus and Platanus acerifloium...I can't even blame this confusion on common names.
Thanks for reading and adding to the topic!