Sherriff and Ludlow first met in Kashgar, Chinese Turkestan, where their shared love of ornithology, plants and travel led to a life-long partnership. They travelled widely in Sikkim, Bhutan and Tibet collecting and documenting specimens. In 1933-34, they travelled to Tibet, Nang-kartse, Gyantse and back to India selecting over 500 plants and seeds; their collection included 69 species of rhododendron, 15 new to science.
