Ting Li

Xerocomus porophyllus sp. nov., morphologically intermediate between Phylloporus and Xerocomus

Xerocomus porophyllus, discovered from Dinghushan Biosphere Reserve in Guangdong province (southern China), is described as a new species. It is a morphologically intermediate taxon between Phylloporus and Xerocomus since its hymenophore is lamellate around the stipe but strongly anastomosing to distinctly faveolate or poroid towards pileus margin. Molecular analyses of nuclear rDNA ITS and LSU sequences, however, indicate that it has a closer genetic relationship with Xerocomus than with Phylloporus. Key words— Basidiomycota, Boletaceae, Boletales, phylogeny, taxonomy Introduction Phylloporus Quél. and Xerocomus Quél. belong to the family Boletaceae and have a close relationship, whether Phylloporus has been considered as a primitive group in the family (Corner 1972) or as a derived genus next to Xerocomus (Binder 1999; Binder & Hibbett 2006). Molecular data have shown the Xerocomus subtomentosus complex to be closely related to Phylloporus (Binder 1999). The lamellate hymenophore in Phylloporus and the wide poroid or tubular one in Xerocomus are still used as the main morphological characters for differentiating the two genera (Neves & Halling 2010; Neves et al. 2012). Worldwide, Phylloporus encompasses about 70 named species (Neves et al. 2012), 21 of which have been reported from China (Teng 1963; Zang & Zeng 1978; Li et al. 1992; Bi et al. 1993, 1997; Dai & Li 1994; Zang et al. 1996; Zeng et al. 2012). However, two Chinese records should be excluded because the type specimen of Phylloporus scabrosus M. Zang is a Lentinus sp., and Chinese exsiccatae labelled as “Phylloporus rhodoxanthus” were misidentified (Zeng et al. 2012). Although some mycologists have incorporated Xerocomus into Boletus (Corner 1972, Kirk et al. 2008), other authors still treat it as an independent