Osservazioni fitosociologiche sul «Lago Gurrida» (Sicilia Nord-Orientale)

Phytosociological observations on «Lago Gurrida» (N-E Sicily). The results of a phytosociological research on the vegetation of «Lago Gurrida» are given. It is a little marshy area at present partially bonified, which is localized at the base of the N-W slope of Etna and is fed mainly by the water of Flascio river. The natural vegetation is represented by very peculiar plant-communities which are linked to the lenght of the submersion period. The surveyed associations are the followings: Myriophylletum spicati Soò 1927, submerged monophytic vegetation belonging to Potametea; Eleocharido-Alismetum lanceolati ass. nov., hygrophilous association referred to Phragmition which is represented by a more hygrophilous subassociation (bolboschoenetosum) and by a less hygrophilous subassociation (alismetosum); Phragmitetum communis (W. Koch 1925) Schmale 1939 forming a dense monophytic vegetation; Carici otrtibae-Juncetum inflexi ass. nov. of Agropyro-Rumicion crispi, physionomically characterized by the dominance of Juncus inflexus; Epilobio hirsuti-Agropyretum repentis ass. nov., belonging to the same alliance of the previous association and it is represented by meadows of Agropyron repens; Coronopo-Sisymbrielletum dentatae ass. nov. of Heleochloion, which represents a ephemeral vegetation characterized by the occurrence of Sisymbriella dentata rare endemic species of Sicily and S. Calabria; Rubo-Crataegetum brevispinae O. Bolòs 1962, thorny scrub vegetation belonging to Pruno-Rubion ulmijolii. Besides some plant-communities not very well characterized from the floristical and structural point of view occur; they are indicated as community of Dipsacus fullonum and Cirsium italicum, belonging to Plantaginetalia majoris and frequent in the uncultivated surfaces of bonified areas, and as community of Salix alba and Salix purpurea, riparian wood of Populion albae