I have several "Green Hornet's". The grower who provided the scion tells us that it is a japonicum. Several nursery's tell us that it is a palmatum. Does anybody know where this cultiver came from?. Maybe the answer could be found there. Mike
Listed by Vertrees (Gregory), Japanese Maples under Acer palmatum: "This promising cultivar is unusual in being a green dissectum with red fall color. The finely dissected leaves are a bright spring green with the young emerging leaves tinged in orange red. 'Green Hornet' is a very vigorous plant with long sweeping pendulous shoots."
Here in the West 'Green Hornet' has been offered by FW Byles Co in WA, Lake's nursery in CA, and Greer Gardens in OR.