Pollen and spores are ubiquitous, and preserve exceptionally well. This, with their great structural diversity, offers exceptional opportunities for integrating findings from studies of both recent and fossil material, and for developing new insights into pathways and processes of diversification. This volume brings together novel approaches from such diverse fields as palaeobotany, ontogeny, molecular biology, and systematics. Three main issues are discussed: the evidence provided by the fossil record, the contribution of ontogenetic data, and methods of systematic analysis. The information provided will be of great interest and relevance to such disparate disciplines as vegetational history, geology, plant taxonomy, and plant evolution.