Acer mono Maxim.

Picture 1 in Japan, Honshu, Chuzenji Lake, June 2010
Pictures 2, 3, 4 & 5 in Japan, Shikoku, Omogo, May 2008
Distribution : Japan, China, Manshuria, Korea, Sakhalin, Mongolia, SE.Siberia

Description in Bull. Phys. Math. Acad. Sc. Petersb. xv. (1856) 126