Rhododendron lepidotum Wall.

in Sikkim, Tsomgo lake, near Karponang & in Kyongnosla Alpine Sanctuary, july 2003 (pictures 1,2, 5, 6, 7 & 8)
in Nepal, Langtang park, june 2000 (pictures 3 & 4)
in Nepal, Muktinath, june 2000 (picture 9)