Background
Osborn was born at Great Clacton, Essex, England, son of John Ashton Osborn, a schoolmaster, and his wife Harriet Mary, née Andrew.
Osborn was born at Great Clacton, Essex, England, son of John Ashton Osborn, a schoolmaster, and his wife Harriet Mary, née Andrew.
Sometime later the family moved to Burnley, Lancashire where his father worked at the Grammar School. In 1928 Osborn accepted the chair of botany at the University of Sydney, he studied the coastal vegetation of New South Wales. Osborn was dean of the faculty of science from 1930 to 1933 and a fellow of the university senate from 1931.
In 1937 Osborn became Sherardian Professor of Botany at the University of Oxford, was elected fellow of Magdalen College and admitted to the degree of Master of Arts On retiring in 1953, Obsborn returned to Australia and lived mostly in Adelaide until his death.