Holboellia latifolia Wall.

in Nepal, near Dunche, June 2000 (picture 1)
in NE.India, Darjeeling, Manebhanjan, July 2003 (pictures 2, 3 & 4)
in Darjeeling, near Tonglu, July 2003 (picture 5)
in Sikkim, Gangtok, July 2003 (picture 6)
in China, Emei Shan, June 2002 (pictures 7& 8)