The study of how a flower develops can be considered floral morphology in its fullest sense. Floral morphology should include, not only the mature floral structure, but also the succession of morphological changes which can be seen during ontogeny. Developmental studies have been revolutionized in the last 15 years by the availability of SEM (scanning electron microscopy). Comparative floral development is now being used as an approach to understanding the relationship between structure, systematics, and phylogeny. It also serves as a bridge between functional morphology and physiology of the flower. This volume contains contributions dealing with the morphological, systematic, and phylogenetic aspects of floral development. The chapters are presentations which were included in a double symposium, "Floral development: Evolutionary aspects and special topics", held on 29 July 1987 in Berlin as part of the XIV International Botanical Congress.