Hapalopilus P. Karst.

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 : 11

Hapalopilus P. Karst.

Hapalopilus Revue Mycologique Toulouse 3(9): 18 (1881).

Type species.

Hapalopilus nidulans (Fr.) P. Karst. (= Hapalopilus rutilans (Pers.) Murrill)

Description.

Pileate to resupinate polypores with soft to cottony corky, ochre to pink basidiocarps. Hyphal structure monomitic, clamps always present, generative hyphae slightly thick-walled, 2-5.5 µm in diameter, CB−, IKI−, KOH−, covered with granular, golden yellow pigment that dissolves in KOH turning purple. Cystidia absent. Hymenial cells relatively long, 12 –25×4.2– 5.5 µm. Spores ellipsoid to subcylindrical, thin-walled, 3 –5×2– 3.2 µm.

Remarks.

Altogether 36 species have been combined to Hapalopilus , most of them bright-colored, soft polypores with a monomitic, clamped hyphal system. The genus type Hapalopilus nidulans belongs to the Phanerochaetaceae as shown by us (Figure 2) and previous work ( Binder et al. 2005, Binder et al. 2013, Floudas and Hibbett 2015). Other species traditionally referred to this genus ( Hapalopilus alborubescens , Hapalopilus croceus , Hapalopilus ochraceolateritius etc.) belong to other lineages of the Polyporales ( Niemelä et al. 2012, Dvořák et al. 2014), and their phylogeny and taxonomy will be revisited on further occasion.

Here we include four species in Hapalopilus in the strict sense, three of which are new to the genus. According to our data, Hapalopilus rutilans is a holarctic species, Hapalopilus eupatorii and Hapalopilus ribicola are found in Europe, and Hapalopilus percoctus is so far only known from the type locality in Botswana. These species are morphologically very similar, and thus Hapalopilus as a genus is morphologically easy to characterize. The purple KOH reaction of Hapalopilus is shared by its pigmented, corticioid relatives in Rhizochaete ( Wu et al. 2010, Chikowski et al. 2016).

Unlike other Phanerochaetaceae polypore genera recognized here, Hapalopilus has a typical polypore subhymenium of sinuous, tightly packed, interwoven hyphae instead of the loose corymb type seen in Oxychaete , Phanerina , Phanerochaete and Riopa . Also Phlebiopsis species (including Castanoporus ) have an interwoven subhymenium.

Morphological, ecological and geographic data of Hapalopilus species are summarized in Table 3.