The physiological ecology of amphibious and intertidal plants was the subject of a special symposium held by the British Ecological Society in March, 1985. This was the first time that this particular aspect of plant life had been the subject of a symposium and it brought together eminent specialists from all over the world, many of whom have contributed to this volume. `Amphibious' is not a word usually associated with plants, yet there are many species of higher plants that have to adjust suddenly from dry-land to an aquatic existence. The problems encountered by both crops and natural flora under soil flood or tidal flood conditions formed the discussion of this international meeting, organized by the Department of Plant Biology and Ecology of the University of St Andrews, Fife. This special publication of the British Ecological Society was produced as a tribute to D. H. N. Spence