AbstractThe occurrence of fifteen xeromorphic adaptations in mosses of gypsiferous sites in south-east Spain, the most arid part of Europe, was analysed. The characteristic species of agypsophilous moss community(Crossidium crassinerve, Tortula revolvensandAloina bifrons) were evaluatedin order to compare their degree of adaptation to the habitat with the degree of adaptation of other groups of species of this association.