Abstract
We conducted a phytosociological study of the communities hosting the rare and endangered fern Adiantum capillus-veneris in the foothills of the Julian Alps, in Karst and in Istria. Based on a comparison with similar communities elsewhere in the southern Alps (northern Italy) we classified most of the recorded stands into the syntaxa Eucladio-Adiantetum eucladietosum and -cratoneuretosum commutati. Releves from the southern Julian Alps, located in comparatively slightly colder and moister local climate and the dolomite bedrock are classified into the new subassociation -hymenostylietosum recurvirostri subass. nova. Stands with the abundant occurrence of the liverwort Conocephalum conicum, are classified in to the new subassociation -conocephaletosum conici subass. nova. Stands in conglomerate rock shelters along the Soča at Solkan are classified into the new association Phyteumato columnae-Adiantetum ass. nova, a community of transitional character between the classes Adiantetea capilli-veneris and Asplenietea trichomanis.