Acer palmatum

Over the past century or so, the number of different cultivars (those forms distinct enough to be selected by a grower) has increased almost exponentially with over a thousand cultivars currently known.
In order to try to make some sense of this seemingly bewildering variety of names, shapes and forms, renowned nurseryman Cor van Gelderen has produced an excellent classification system, which is endorsed by The Maple Society and we are pleased to use it here.