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The phylogeny of the genera traditionally classified in the family Pluteaceae (Agaricales, Basidiomycota) was investigated using molecular data from nuclear ribosomal genes (nSSU, ITS, nLSU) and consequences for taxonomy and character evolution were evaluated. The genus Volvariella is polyphyletic, as most of its representatives fall outside the Pluteoid clade and shows affinities to some hygrophoroid genera (Camarophyllus, Cantharocybe). Volvariella gloiocephala and allies are placed in a different clade, which represents the sister group of Pluteus, and a new generic name, Volvopluteus, is proposed to accommodate these taxa. Characters such as basidiospore size and pileipellis structure can be used to separate Pluteus, Volvariella and Volvopluteus. The genus Pluteus is monophyletic and includes species with partial veil traditionally classified in the genus Chamaeota. The evolution of morphological features used in the infrageneric taxonomy of the genus, such as metuloid cystidia and pileipellis structure, was analyzed. Agreement between the molecular phylogeny and morphological subdivision of Pluteus is, generally speaking, good, though some rearrangements are necessary: (i) species with non-metuloid pleurocystidia and pileipellis as a cutis are placed either in sect. Celluloderma, together with the species characterized by a hymenidermal pipeipellis, or in sect. Pluteus, with the metuloid bearing species; (ii) subdivision of sect. Celluloderma according to the presence/absence of cystidioid elements in the pileipellis is not supported by molecular data., (Copyright © 2010 The British Mycological Society. All rights reserved.)

A new species of Infundibulicybe (viz. I. mediterranea sp. nov.) is described from Sardinia based both on morphological and molecular ITS data. The species, a close ally of I. gibba, differs from the latter in the darker tinges of the basidiomata, the stipe, which is nearly concolorous with the pileus, and smaller basidiospores. Drawings of the main micro-morphological features as well as a color photograph of fresh basidiomata in situ are provided.

Leucoagaricus decipiens and La. erythrophaeus, are described as new from Sardinia, Italy, and California, USA, respectively. These sister species show distinct reddening when touched on all parts of the basidiocarps and darken on drying. Their collariate lamellae, broadly cylindrical to utriform cheilocystidia and trichodermal pileus covering distinguish them morphologically from other species in sect. Piloselli, while nrITS and EF1-alpha sequences distinguish them from each other. Leucoagaricus erythrophaeus has been known under the name Lepiota roseifolia, but the type collection of this species does not fit the interpretation.