Although most so-called Japenese Maples are
cultivars of Acer palmatum, a few are selections
from other species, including A. japonicum,
A. shirasawanum, A. circinatum, and others.
These are typically larger trees than A. palmatum
cultivars, but there are some exceptions.

A. japonicum is an Asian species, and has
recently been split, with the second species
being named A. shirasawanum. Japonicums
tend to have boad, orbicular leaves with
shallow lobes, but lobes are very deeply cut
on a few cultivars.

A. circinatum, Vine Maple, is a species from
the Pacific coast of North Ameirca, but
closely related to A. palmatum and A.
japonicum. All three species are known for
their showy fall color. A. circinatum is a
woodland tree, and requires protection from
hot afternoon sun.