Livingstone, David, 1813-1873. Letter to William J. Hooker, 16 May 1857. Images copyright Royal Botanic Gardens, Kew. Images reproduced with the kind permission of the Board of Trustees of the Royal Botanic Gardens, Kew (http://www.kew.org/). As relevant, copyright Dr. Neil Imray Livingstone Wilson. Creative Commons Attribution-NonCommercial 3.0 Unported (https://creativecommons.org/licenses/by-nc/3.0/). 