Rheum acuminatum J.D. Hooker & Thoms.

in Sikkim, Kyongnosla Alpine Sanctuary, July 2003 (picture 1)
in China, Yunnan, Tuguancun, June 2002 (picture 2)
in China, Yunnan, Zhongdian, June 2002 (picture 3)
in Sikkim, Tsomgo lake, July 2003 (pictures 4 & 5)

Description in Bot. Mag. 81: t. 4877. 1855