I'm running about 0 for 10 in guessing trees around here, so I think I'm even pushing it calling this Acer palmatum, but if someone identifies it, I'll move it to the proper thread in the Acer palmatum dissectum photos gallery. I can't figure out if there's a place to ask in the Maples forum. I also can't imagine how anyone could tell all these things apart unless they come with a tag. This is a Stanley Park (Vancouver, BC) tree, near the Pavilion; photo taken October 27, 2008.
Definitely an acer palmatum cultivar. I'm not familiar with the array of cultivars now available, but it's not the wild form, which has a leaf much like vine maple. I've never seen the wild form for sale.
There are thousands of named cultivars of Acer palmatum, many of them introduced in the last 15-20 years by people who do not follow the established practice of observing it for many years and subjecting the proposed cultivar to some kind of peer review to confirm uniqueness. In the dissectum group there are hundreds. In any case leaf form and fall colors are generally not sufficient for proper identification, spring and summer colors are usually needed. In addition this may just be a seedling not a grafted specimen of a named cultivar. Gomero
