Joseph Franz Rock (1884–1962), originally from Vienna, made his name as an explorer of the flora of his new home, the Hawaiian Islands. After World War I, American institutions sent him as a botany explorer to southern China and the Tibetan border regions. The trips resulted in comprehensive botanical collections as well as pioneer studies of the non-Chinese Naxi tribe, which has its own pictographic script and bases its rituals on the old Bon religion of Tibet. This volume of correspondence with the American taxonomist E. H. Walker provides a vivid impression of Rock's work and his methodology. Walker was Rock's contact to the scholarly world, his information resource, and his bibliographer and helpful colleague. With indices. The editor, trained as a Sinologist and bibliographer, is a director of the Berlin State Library and professor at the Free University of Berlin. He is the author of two previous monographs on Rock.