A surprisingly large number of pteridophytes are able to meet the challenges of life in arid and seasonally dry habitats. This symposium will explore some of the structural, physiological, ecological, genetic, and other life-history adaptations of ferns and fern allies growing in regions where moisture deficit and high solar irradiation are part of a syndrome of factors providing strong selection pressures on evolution of the local flora. Attendant problems of taxonomic and phylogenetic interpretation that have resulted from such adaptations and directed evolution will be showcased. Studies on pteridophyte responses to aridity are still an emerging field of study, so the symposium will reflect future research needs as much as summarizing present knowledge of selected topics.

Key words: arid lands, deserts, pteridophyte