Amyloceraceomyces S.H. He, gen. nov.

Index Fungorum number: MB830032; Facesoffungi number: FoF 06037

Etymology: Amylo: referring to the amyloidity of the basidiospores; ceraceomyces: a corticioid genus with similar anatomical characters.

Basidiocarp Annual or perennial, resupinate, effuse to slight effuse-reflected, separable, pellicular to membrana- ceous, stratified. Hymenophore smooth, white, cream to pale yellow; not cracking or sparsely cracking after dry; margin thinning out, fimbriate. Hyphal system monomitic; generative hyphae with clamp connections. Cystidia absent. Basidia clavate to subcylindrical, with a basal clamp connec- tion and four sterigmata. Basidiospores narrowly cylindrical, hyaline, thin-walled, smooth, amyloid, 7–10 × 2–2.5 µm. On angiosperm branch. Rot type unknown.

Type species: Amyloceraceomyces angustisporus S.H. He.

Notes: – Amyloceraceomyces is mainly characterized by the pellicular to membranaceous, stratified basidiocarps, a monomitic hyphal system with nodose septate hyphae, absence of sterile organs, and cylindrical smooth thin-walled amyloid basidiospores. Phylogenetically, Amyloceraceomy- ces formed a distinct lineage in Amylocorticiales (Fig. 84). Morphologically, the genus is almost indistinguishable from Amylocorticium which, however, has ellipsoid to allantoid basidiospores and causes a brown rot mainly on gymno- sperm wood (Pouzar 1959; Hjortstam 1980; Gilbertson and Lindsey 1989). Amyloathelia Hjortstam and Ryvarden and Amylocorticiellum Spirin & Zmitr. differ from the new genus by having thick-walled basidiospores (Hjortstam and Ryvarden 1979; Zmitrovich and Spirin 2002). Ceraceomyces Jülich has similar anatomical structures to Amyloceraceomy- ces, but differs in having basidiospores without reaction in IKI (Bernicchia and Gorjón 2010). Amyloceraceomyces is also similar to Melzericium Hauerslev by sharing smooth, thin-walled amyloid basidiospores and the absence of cys- tidia, but the latter has stalked basidia and wider basidi- ospores (3–6 µm, Bernicchia and Gorjón 2010).

Fig. 84 Phylogenetic position of Amyloceraceomyces angustisporus and Amylocorticium ellipsosporum inferred from the ITS and LSU sequences. Bootstrap support values (ML and MP) ≥ 50% and Bayes- ian posterior probabilities ≥ 0.95 are given near nodes respectively. The tree is rooted with Jaapia argillacea (KHL 11734, CBS252.74) and J. ochroleuca (KHL 8433). The new isolates are in bold