Nomenclature of Italian syntaxa of the classes Festuco hystricis-Ononidetea striatae and Rumici-Astragaletea siculi

This article aims at revising the nomenclature of the Italian syntaxa belonging to the Festuco hystricis-Ononidetea striatae and Rumici-Astragaletea siculi classes according to the EuroVegChecklist at the ranks of class, order and alliance. The correct syntaxon names, authors' citations, nomenclatural types and causes of invalidity and illegitimacy are identified and reported. Two classes (Cerastio-Carlinetea nebrodensis, Festuco hystricis-Ononidetea striatae), two orders (Erysimo-Jurineetalia bocconei, Euphorbietalia myrsinitae) and three alliances (Cerastio-Astragalion nebrodensis, Armerio denticulatae-Stipion etruscae, Sideritidion italicae), treated as valid syntaxa in the EuroVegChecklist, turned out to be invalidly published. The new class Helianthemo cani-Seslerietea nitidae is here described to replace the Festuco hystricis-Ononidetea striatae. The Erysimo bonanniani-Jurineetalia bocconei is validated to contain the new alliance Odontarrheno nebrodensis-Koelerion splendentis and the validated Cerastio tomentosi-Astragalion nebrodensis. Since the Koelerio brutiae-Astragalion calabrici turned out to be a superfluous name, the Plantaginenion serpentinae is here raised to the rank of alliance to include the silicicolous pulvinate scrub of the Sila Mountains. The order Festuco-Seslerietalia nitidae, previously deemed invalid, is proven to be validly published, and it is the earliest available name for the supra- and oromediterranean xeric calcicolous grasslands of the Italian Peninsula. Three mutations of names are provided, and the Astragaletum calabrici is lectotypified.