Clarence James Hickman (1 April 1914 – 24 September 1980) was a British-Canadian mycologist.
He is noteworthy for his discovery in 1940 that the oomycete species Phytophthora fragariae is the cause of the disease red stele (aka red core root disease) in strawberry plants.
From 1938 to 1944 he was a research officer at the Plant Pathology Laboratory at Harpenden.
[3] For the British Mycological Society he served as the secretary from 1948 to 1952 and as the president for a one-year term from 1957 to 1958.
[3] In 1958 his presidential address gave an excellent summary review of the plant-damaging genus Phytophthora, including the biology of its survival and dispersal, the range of its plant hosts, and its physiological specializations.