British botanist (1930-2008).
John Francis Michael Cannon (22 April 1930 – 31 March 2008) was a British botanist who held the role of Keeper of Botany at the Natural History Museum between 1978 and 1990. Cannon joined the Department of Botany at the British Museum (Natural History), as it was then known, in October 1952. He was appointed as a scientific officer in the 'General Herbarium', with responsibility for one of the four sections into which the herbarium was divided. These were families 67 (Myrtaceae) to 107 (Asclepiadaceae). The following year he was given responsibility for planning and building a major new botany