Polymers of fructose - fructans - are second only to starch as plant storage carbohydrates. In some taxa, notably the grasses, they dominate: they are turned over rapidly in leaves, and they can constitute half the weight of storage organs. They are also abundant in many micro-organisms. In spite of their biological importance, many aspects of their metabolism and function are poorly understood. Their synthesis is controversial, even the identity of the enzyme(s) involved being disputed, and their degradation comparatively little studied. Exactly what roles they fulfil which are not shared by starch and sucrose is far from clear, and claims that they are involved in drought or cold tolerance are hard to substantiate. This volume forms a collection of edited papers from the Third International Symposium on Fructan, which took place in Utah in July 1996.