..saturday i buy this lovely maples in one flower show (Murabilia ,Lucca ,Italy UE) i order Acer h. from one UK nursery Crug farm ,in book Maples of the World pag.128 i read :Murray combined Acer h. as a subsp.of Acer campbelli in 1977!!there are a new classification? now is one species ?however is very beautiful with big palmate leaves!
Published by Gagnepain in 1948; native to SE Asia (Laos, etc.). I'd ignore any combination published by A.E.Murray, not exactly a well-regarded botanist.