Hydnophanerochaete Sheng H. Wu & C.C. Chen

Chen, Che-Chih, Wu, Sheng-Hua & Chen, Chi-Yu, 2018, Hydnophanerochaete and Odontoefibula, two new genera of phanerochaetoid fungi (Polyporales, Basidiomycota) from East Asia, MycoKeys 39, pp. 75-96 : 75

Hydnophanerochaete Sheng H. Wu & C.C. Chen gen. nov.

Type species.

Hydnophanerochaete odontoidea (≡ Phanerochaete odontoidea ).

Etymology.

From hydnoid + Phanerochaete, referring to the hydnoid hymenial surface and a close affinity to Phanerochaete .

Description.

Basidiocarps effused, adnate, ceraceous. Hymenial surface at first buff, with age turning ochraceous to pale brown, slightly tuberculate to grandinioid when young, becoming odontioid to hydnoid with age, without colour changes in KOH. Aculei conical to cylindrical, ca. 1-4 per mm, up to 700 μm long.

Hyphal system essentially monomitic; generative hyphae simple-septate. Subiculum fairly uniform, composed of a basal layer, with compact texture; generative hyphae somewhat horizontal, colourless, thick-walled; quasi-binding hyphae present near substratum, colourless. Hymenial layer thickening. Trama of aculei of compact texture; generative hyphae somewhat vertical, colourless, thick-walled. Cystidia lacking, but projecting hyphal ends in the hymenium may be present. Basidia clavate, 4-sterigmate. Basidiospores ellipsoid to cylindrical, smooth, thin-walled, inamyloid, non-dextrinoid, acyanophilous.

Remarks.

Hydnophanerochaete is morphologically similar to the genus Hydnophlebia ( Telleria et al. 2017). Both genera have resupinate basidiocarps with odontioid to hydnoid hymenial surface, a monomitic hyphal system, ordinarily simple-septate hyphae and similar basidiospore shape. However, we note three distinguishing differences. First, Hydnophlebia has membranaceous basidiocarps usually with rhizomorphic margin, while Hydnophanerochaete has ceraceous basidiocarps with fairly determinate margin. Second, occasional single or multiple clamp connections are present in subicular or aculei hyphae of Hydnophlebia , whereas they are lacking in hyphae of Hydnophanerochaete . Third, Hydnophlebia occasionally bears tubular to ventricose leptocystidia, which are lacking in Hydnophanerochaete .

Little morphological differences exist between Hydnophanerochaete and Odontoefibula : both genera have monomitic hyphal system with simple-septate hyphae and are lacking cystidia. However, Hydnophanerochaete is distinguished from Odontoefibula by its basidiocarps without colour change in KOH; additionally, its subiculum is compact, not dense.

Phanerodontia Hjortstam & Ryvarden, a recently proposed genus typified by P. dentata Hjortstam & Ryvarden ( Hjortstam and Ryvarden 2010), is also morphologically similar to Hydnophanerochaete . However, the latter has a compact subiculum and quasi-binding hyphae near the substratum. Phanerodontia accommodates four species [ P. chrysosporium (Burds.) Hjortstam & Ryvarden, P. dentata , P. irpicoides (Hjortstam) Hjortstam & Ryvarden and P. magnoliae (Berk. & M.A. Curtis) Hjortstam & Ryvarden], all of them possessing long leptocystidia ( Hjortstam and Ryvarden 2010), whereas this structure is lacking in Hydnophanerochaete . Moreover, phylogenetically, strains of two species ( P. chrysosporium and P. magnoliae ) were recovered in Phanerochaetaceae which is only distantly related to Hydnophanerochaete (Fig. 1). However, the generic type has not been sequenced so far.