The Araceae are a diverse and highly variable family of tropical plants, and the evolutionary relationships among its genera (approximately 110) and species (2,300) are poorly understood. Dr. Michael Grayum has completed a monograph entitled "External Pollen Ultrastructure of the Araceae and Putatively Related Taxa", in which he presents a survey of pollen morphology in almost 400 species representing nearly all genera in the family. The survey uses light and scanning electron micrographs to reveal the fine structure of pollen grains that characterize each species. Dr. Grayum's monograph will be published, with NSF support, in the Annals of the Missouri Botanical Garden. The proposed monograph will be an important reference volume for the identification of aroid species using pollen. The morphological data presented in the monograph will open new research avenues for establishing the evolutionary relationships within the family.
