[3] She became interested in studying Calluna vulgaris in 1910,[4][5] and earned a doctor of science degree for work on this topic, also from the University of London.
[4] As part of this research she issued questionnaires to forest departments around the British Empire, most of which were completed and returned.
This provided Rayner with significant insight into their pine growing, particularly in Northern Rhodesia, Tanganyika, and Nyasaland.
[2] In 1926, a discussion at the British Association for the Advancement of Science led Rayner to become more interested in mycorrhiza interactions in conifers.
They had similar research interests and shared laboratory space at Bedford College where Jones was a professor.