- The Wild Flower Key ... How to identify wild plants, trees and shrubs in Britain and Ireland, 1981. Revised by Clare O'Reilly, 2006. Frederick Warne. ISBN 0-7232-5175-4.
- Colour Identification Guide to the Grasses, Sedges, Rushes and Ferns of the British Isles and North Western Europe, 1989. Viking. ISBN 0-670-80688-9.
- The Flora of Hampshire, 1996. Co-authored with Richard Mabey, Lady Anne Brewis and Paul Bowman. Harley Books. ISBN 0-946589-34-8.
- The Observer's book of Grassse Sedges and Rushes, 1974. Frederick Warne & Co. Ltd
For a full list of publications see Obituary in
Watsonia.