Acer palmatum Thunb.

in Japan, Honshu, Mt.Rokko, May 2008 (picture 1)
in Japan, Honshu, Kyoto, May 2008 (pictures 2 to 9)
in Japan, Honshu, Tokyo, June 2010 (pictures 10 to 15)

Description in Fl. Jap. 162