Gymnopus sect. Perforantia (Singer) R.H. Petersen 2016

Petersen, Ronald H. & Hughes, Karen W., 2016, Micromphale sect. Perforantia (Agaricales, Basidiomycetes); Expansion and phylogenetic placement, MycoKeys 18, pp. 1-122 : 8-9

Gymnopus sect. Perforantia (Singer) R.H. Petersen comb. nov.

Basionym.

Micromphale sect. Perforantia Singer. 1948. Sydowia 2: 32.

Diagnosis.

1) Pileipellis, pileus and lamellar tramae and stipe medullary hyphae embedded in slime matrix; 2) pileipellis either: a) a layer of repent, encrusted hyphae, conspicuously clamped, usually with thickened walls (through gelatinization) and embedded in a slime matrix; or b) well-developed Rameales -structure; 3) cheilocystidia often absent, when present either clavate to utriform or siccus -type broom cell-like; 4) stipes usually less than 1 mm broad but often up to 40 mm long; ratio of pileus breadth to stipe length often large (see G. pinophilus ); 5) stipe usually vestured (but see G. glabrosipes ), usually appearing minutely barbed (30 ×); 6) lower stipe of dark, somber color, from dark sooty brown to virtually black; 6) rhizomorphs almost always present, always black, from <2-40 × 0.2-0.7 mm, branched or unbranched; 7) basidiospores without significant dimension differences; 8) species apparently more or less host-specific, fruiting on dead conifer needles or rotting deciduous leafy debris; 9) pleurocystidia consistently present, fusiform, varying somewhat in distal morphology; 10) clamp connections ubiquitous.

Commentary.

Antonín and Noordeloos (1997) recognized Gymnopus sect. Vestipedes subsect. Impudicae , including G. perforans , based, it would seem on the fetid odor of basidiomata of the included taxa. Later ( Antonín and Noordeloos 2010), subsect. Impudicae was accepted at section rank, but basically included the same taxa as before. Wilson and Desjardin (2005) indicated that G. perforans formed its own clade sister to that of G. (Micromphale) foetidum and other mainstream odious Gymnopus taxa. Based on the present study, the original Micromphale sect. Perforantia is found to be more closely related to the Gymnopus (Marasmius) androsaceus complex, not inclusive of G. foetidum and other Gymnopus sect. Impudicae .

Molecular phylogenetic information is available for only few taxa accepted (or proposed) here. For “morpho-taxa,” some outline employed to justify their description in this paper is owed the reader. Unfortunately, almost every morphological character includes a caveat for collections which violate one or more characters. The following diagnoses are offered: