The Lygeo-Stipetea class in Sicily.

Basing on literature data and unpublished relevés from Sicily, a survey of the syntaxa belonging to the class Lygeo-StipeteaRivas-Martínez 1978 is presented. This perennial vegetation is characterized by the dominance of big caespitose hemicryptophytes,and it is widely distributed in Sicily from the sea level up to 1500 m a.s.l. The class is represented in Sicily by two orders, floristicallyand ecologically well differentiated: Lygeo-Stipetalia, including the sole alliance Moricandio-Lygeion exclusively of clayey substrates,and Hyparrhenietalia hirtae, including five alliances (Hyparrhenion hirtae, Avenulo cincinnatae-Ampelodesmion mauritanici,Thero-Brachypodion ramosi, Bromo-Oryzopsion miliaceae, and Arundion collinae) occurring on various substrates. Within the class, 50 associationshave been recognized. To support the syntaxonomic proposal, a multivariate numerical analysis, considering literatureand personal data, has been performed. Nomenclature, floristic settlement, ecology, syndynamism and chorology are examined foreach syntaxon.