Sir Joseph Dalton Hooker OM, GCSI, CB, MD, FRS (30 June 1817 10 December 1911) was one of the greatest British botanists and explorers of the 19th century. Hooker was one of the founders of geographical botany, and Charles Darwin's closest friend. He was Director of the Royal Botanical Gardens, Kew, for twenty years, in succession to his father, William Jackson Hooker, and was awarded the highest honours of British science.