Paramycetinis R.H. Petersen, gen. nov.

Index Fungorum number: IF 555792; Facesoffungi number: FoF

Basidiomata diminutive, associated with dominant black rhizomorphs; a monophyletic clade.

Type species: Paramycetinis austrobrevipes R.H. Petersen

Etymology: reflecting the sister phylogenetic relationship to Mycetinis.

Basidiomata combining characters of Gymnopus sect. Micromphale subsect. Perforantia, Gymnopus sect. Androsacei, and Marasmius sect. Sicci, minute to small, arising as rhizomorph branches or separate from rhizomorphs. Pileus small (3–15 mm broad), some shade of brown or vinaceous brown, sometimes sulcate-striate, smooth or minutely pruinose; pileus trama thin, pliant. Lamellae adnexed to adnate, sometimes attached to an adherent pseudocollarium, close to subdistant, from ridge-like to well-developed, usually with lamellulae in 1–2 ranks, off-white to dull vinaceous gray. Stipe capillary,≤3 mm broad, terete, more or less equal, solid to stuffed, glabrous-shining to minutely velutinous, brown to brown-black, especially downward, insititious (when not a rhizomorph branch). Rhizomorphs common, ranging from very slender to stout, sometimes dominant and forming loose nets, usually black. Pileipellis commonly involved in slime as a matrix and/or as gelatinizing hyphal walls, usually including diverticulate hyphae and broom cell-like hyphal termini. Pleurocystidia ubiquitous, narrowly to broadly fusiform; contents more or less homogeneous, occasionally vaguely partitioned. Basidia clavate, 4-sterigmate. Basidiospores thin-walled, smooth, inamyloid, white or off- white in deposits. Cheilocystidia present, arbuscular (stalked, branched) or broadly clavate, with or without diverticula. Stipe medullary hyphae strictly parallel, usually involved in a slime matrix. Caulocystidia present or absent, when present gregarious to scattered (not a dense turf), setoid. Clamp connections present. Molecular analysis resolving a monophyletic clade associated with Mycetinis.

Key to taxa of Paramycetinis

  1. Rhizomorphs stout (>1 mm diam), forming loose nets; basidiomata arising from or separate from rhizomorphs; cheilocystidia clavate with clusters of apical

setulae (Tasmania)…………………………………….. Pa. austrobrevipes

  1. Rhizomorphs slender (<1 mm diam), extensive; basidiomata arising separate from rhizomorphs; cheilocystidia clavate, without diverticula; fruiting on

dead leaves and twigs of Nothofagus (New Zealand)    Pa. caulocystidiatus