Fulvifomes imbricatus and F. thailandicus (Hymenochaetales, Basidiomycota): two new species from Thailand based on morphological and molecular evidence

Fulvifomes, which belongs to Hymenochaetaceae, is characterized by a combination of annual to perennial and non-resupinate basidiocarps with an homogeneous or duplex context, a monomitic to dimitic hyphal system, lack of hyphoid and hymenial setae, and subglobose to ellipsoid, yellowish to brown and thick-walled basidiospores. Specimens collected in Chiang Mai, Thailand, and subjected to morphological examination and phylogenetic analysis were determined as F. fastuosus and the newly described species F. imbricatus and F. thailandicus. Fulvifomes imbricatus is characterized by perennial and imbricate basidiocarps, a concentrically sulcate and uncracked pileal surface, a duplex context with a black cuticle, thin tube layers (less than 3 mm thick), a dimitic hyphal system and an absence of cystidioles, whereas F. thailandicus is distinguished by perennial basidiocarps, applanate pilei, a concentrically sulcate and cracked pileal surface, an homogeneous context, a dimitic hyphal system and the presence of cystidioles. The phylogenies inferred from nuclear large subunit ribosomal DNA and internal transcribed spacer sequences showed that the two new species formed distinct lineages from other sampled species in the Fulvifomes clade. In addition, Inonotus luteoumbrinus and I. porrectus were nested within the Fulvifomes clade.