Harold Trevor Clifford (1927–2019), commonly known as Trevor Clifford, had a highly versified career, starting with a PhD in 1955 from the University of Durham, England under the supervision of David Henriques Valentine (1912–1991). He spent 3 years post graduation teaching agricultural botany in Nigeria at the University of Ibadan before returning to his home country of Australia. He began teaching at the University of Queensland in 1958 and remained there for 34 years before retiring. As of 1970 he considered his speciality to be "taxonomy, experimental and numerical", but is also well known for his publications which number in the hundreds including multiple textbooks aimed at the beginner student such as An Introduction to Numerical Classification (1975), Identifying Grasses (1977), and The Families of the Monocotyledons (1985). Post retirement he turned his interests to Paleobotany, studying fossilized plants at Queensland Museum and publishing research until his death in 2019.