Article

On the base of the fìnding of new slations of Carex Rrioletii in Tuscany, our chorological, ecological and karyological knowledge of this rare pian t of the mediterranean-ponlic flora is brought up to date. In Tuscany there had been no data about this elusive species for almost a century, as a consequence of thc difficult accessibility of the growing sites of ihe populations, their small area, and of the anthropic alterations occurred in two of the three localities in which it was found in the pasl. The populations are all restricted to shady and mesic forest habitats of the meditemmean and submediterranean belt with a conservative power for species of the tethyan-tertiary flora. C. Rrioletii ha s 2n ~ 48 small-sized chromosomes, an uncommon number within the genus Carex. Although less rare than previously thought, this species could become vulnerable lo extinction because of its low adaptive capacity to changed ecological conditions and ex ansion inability connected probably to its reproductive biology and to the absence of vegetative spreading systems.