Article révisé par les pairs
Résumé : Evolutionary processes on islands, and the attributes of rare plant species restricted to islands have received increasing attention in the last decade, but most of the evidence comes from oceanic archipelagos while continental islands have been much less studied. We test if narrow endemic species of Aegean islands (E Mediterranean region) have evolved particular trait values and ecological attributes. In 64 pairs of congeneric species i.e., an island endemic and a congeneric widespread species, we compared morphological traits (both vegetative and reproductive), and altitudinal range using a phylogenetically constrained multilevel model. Island endemics had larger propagules, larger petals, shorter stems, shorter flowering duration, and they occupied a narrower altitudinal range. The results are interpreted in terms of lower competitive ability and lower dispersal capacity in Aegean endemics. Larger corolla could be accounted for by competition for pollinators in insect-rich ecosystems. Field observations are needed to test if island endemics and their widespread congeners occupy distinct niches when in sympatry on the same island.