Arthur Wallis Exell was Deputy Keeper of Botany at the British Museum from 1950-1962. A leading botanist in the fields of systematics and phytogeography, he was especially known for his extensive fieldwork in tropical and sub-tropical Africa.
After schooling in Birmingham, Exell attended Emmanuel College, Cambridge, and in 1924 was appointed to a position in the Botany Department of the British Museum (later the Natural History Museum, London). Exell's first scientific paper dealt with the morphology of three fungal species, while his later specialisation was the Combretaceae family. In his early days at the British Museum, meanwhile, he was responsible for enumerating botanical collections sent from John Gossweiler in Angola.
Exell's first travels in Africa were to the islands of the Gulf of Guinea (São Tomé and Principe, Bioko and Annobon) in 1932-1933. His findings were published as a Catalogue of the Vascualr Plants of S. Tome in 1944, which served as the most complete guide to the islands' flora for many years.
It was through his work in the Gulf of Guinea that Exell became acquainted with Portuguese botanists Professor Luis Carrisso and Dr Francisco A. Mendonça of Coimbra University. With them, and accompanied by his wife, Exell began to investigate the flora of Angola, a Portuguese colony. They were accompanied in their collecting work by Gossweiler, the government botanist in Angola. During their work, Carrisso unfortunately suffered a fatal heart attack. Exell continued to collaborate with Coimbra, particularly Mendonça, in publishing the first volume of the Conspectus Florae Angolensis (1937-1951).
During the Second World War, Exell's skill in Portuguese led to his being employed at the Government Communications Headquarters, Bletchley Park. He also worked as a decoder in Cheltenham, and did not return to his botanical work until 1950.
At the British Museum (Natural History) once more, he established the Association pour l'Etude Taxonomique de la Flore d'Afrique Tropicale (AETFAT) and set in motion the Flora Zambesiaca project. The flora covers the area drained by the River Zambesi, which at the time included the Federation of Rhodesia and Nyasaland, Bechuanaland, the Caprivistrip of Namibia and Mozambique (now Zimbabwe, Malawi and Zambia). He visited these areas in 1955 with Mendonça to organise support and make some collections.
Exell retired as Deputy Keeper of Botany in 1962, in which year he was awarded the Doctor of Science degree by the University of Coimbra. The Order of the British Empire was also conferred upon him, and in 1971 he was honoured with the Portuguese government's Comendador da Ordem de Santiago da Espada. He continued to work on the Flora Zambesiaca at Oxford and Kew, while living in the Cotswolds village of Blockley.
Sources:
Anon, 1962, Taxon, 11(4): 139
Anon, 1993, Taxon, 42(3): 732
A.W. Exell, 1984, "In Memory of Francisco de Ascensão Mendonça", García de Orta – Série de Botânica, 6(1-2): 1-6
E. Launert, 1993, "Obituary: Arthur Exell", The Independent, 18 February 1993.
