Riopa D. A. Reid

Miettinen, Otto, Spirin, Viacheslav, Vlasak, Josef, Rivoire, Bernard, Stenroos, Soili & Hibbett, David S., 2016, Polypores and genus concepts in Phanerochaetaceae (Polyporales, Basidiomycota), MycoKeys 17, pp. 1-46 : 21

Riopa D. A. Reid

Riopa Revue Mycol., Paris 33: 244 (1969).

Type species.

Riopa davidii D. A. Reid (= Riopa metamorphosa (Fuckel) Miettinen & Spirin).

Description.

White, resupinate polypores with shallow pores, 2-5 per mm. Hyphal structure monomitic, clamps absent. Hyphae thin- to slightly thick-walled, similar throughout the basidiocarp, hyphae not swollen, wider (3-5 µm in diameter) in subiculum, a bit narrower in trama (2.8-3.5 µm). Hymenial branching corymb-like. Thin-walled, poorly differentiated hymenial cystidia and conidia in one species. Spores curved cylindrical, sausage-like, thin-walled, mid-sized (4.5 –6.5×2– 3 µm).

Remarks.

Reid (1969) described Riopa as a monotypic genus with Riopa davidii D. A. Reid from Corsica as the sole species. Ryvarden (1991) considered Riopa davidii as a synonym of Ceriporia camaresiana (Bourdot & Galzin) Bondartsev & Singer, in effect making Riopa a synonym of Ceriporia . Pieri and Rivoire (1997) regarded Riopa davidii and Ceriporia camaresiana as separate species, and made the combination Ceriporia davidii . Their concept of the species was mixed, as can be seen already from the spore variation they report. Their specimens from mainland France did seem to represent a species of Ceriporia separate from Ceriporia camaresiana , and consequently Ceriporia davidii was adopted by Bernicchia (2005) and Ryvarden and Melo (2014).

We studied the type of Riopa davidii , and it turned out to be a more recent synonym for Ceriporia metamorphosa (Fuckel) Ryvarden & Gilb. After studying the French material of Ceriporia davidii collected by B. Rivoire, we could also conclude that Ceriporia davidii sensu Pieri and Rivoire (1997) needs to be described with a new name ( Ceriporia pierii ). Ceriporia pierii and also Ceriporia camaresiana belong to the Ceriporia clade and are only distantly related to Riopa (Figure 2).