The genus Hygrophorus has been divided into sections and subsections, which are easily identified with the key based on field characters only. Once in the section or subsection, the species can be identified by means of another key, at times including also microcharacters. The species little known to us along with varieties or forms of dubious validity have been included, always reporting their original descriptions, just for the sake of completeness.
In the present work 43 species, 5 varieties and 2 forms in the genus Hygrophorus and 59 species, 6 varieties and 1 form in the genus Hygrocybe are described.
245mm x 180mm, 80 colour plates (76 by E. Rebaudengo), 102 colour photographs, 109 micrographs made by the author.
Main text in Italian; keys, preface, and materials and methods are also in English.