Flora Iranica, a monumental work on the plants of Iran [Persia]. Edited by Karl Heinz Rechinger of Vienna since 1963 until his death in 1998, Flora Iranica now consists of 181 fascicles and is nearly complete. The Fabaceae with the extensive genera Astragalus and Astracantha are being treated in the most recent volumes, while the club mosses, horsetails, and ferns have not yet been published.
More than ten thousand species of flowering plants, gymnosperms, and ferns have been recorded for the Iranian Highlands. This area is a center of the world's biodiversity, exhibiting many foci of speciation and evolution of higher plant taxa, such as tribes, genera, and species, and of intraspecific evolution, especially non-arboreal xerophytes. The mountainous regions are particularly rich in neondemits: e.g. the Apiceae, Asteraceae, Boraginaceae, Brassicaceae, Fabaceae, Lamiaceae, Plumbaginaceae, Poaceae, and Scrophulariaceae are large families in the Iranian Highland and well represented in the Northern Hemisphere flora. Within these families there are clusters of speciation centers, such as the genus Ferula (53 species) within the Apiaceae, the genus Cousinia (353 species) within the Asteraceae, 126 genera within the Brassicaceae, the genera Astragalus and Astracantha (approximately more than 1000 species) within the Fabaceae, the genus Nepeta (59 species) within the Lamiaceae and the genus Acantholimon (164 species) within the Plumbaginaceae. In addition, the diversity of the flora is enriched by refugia on the southern coast of the Caspian Sea where a good number of species with a one time wider distribution survived glacial times.
The Flora Iranica is the most comprehensive survey available of the flora of the Iranian Highland and adjacent regions. It is an essential foundation for floristic, systematic, and geobotanical research on this area, and it testifies to the tremendous diversity of the flora in this region.