Lyophyllum P. Karst.

Index Fungorum number: IF 18003; MycoBank number: MB 18003

The genus Lyophyllum represents one of the well-known agaric genera with about 116 species names (including synonyms) listed in the Index Fungorum (2023). The genus is widespread in the boreal, temperate, and arid regions, but only a few species are reported from the tropics (Pegler 1986; Singer 1986). The genus has an inconsistent taxonomic history. Traditionally, species of Lyophyllum are characterized by dull-coloured, collybioid, clitocyboid or tricholomatoid basidiocarps and basidia with siderophilous granules (Pegler 1983; Singer 1986; Kalamees 2004). In their phylogenetic analysis of the Lyophyllaceae, Hofstetter et al. (2002) demonstrated that Lyophyllum species fell into three separate groups and the type species of the genus, Lyophyllum leucophaeatum, nested in a clade containing Calocybe. To retain the genus name for the many commonly encountered dull-coloured species of Lyophyllum, conservation of the genus name with the new type L. semitale was proposed (Redhead et al. 2006). Subsequently, Hofstetter et al. (2014) identified a monophyletic lineage, the lyophylloid clade or Lyophyllum sensu stricto, which is composed of species characterized by basidiocarps with brown or dusky pigments and basidia containing siderophilous granules of the macro-type (Clémençon 1986). Some species of Lyophyllum (e.g., L. ambustum, and L. atratum) are reported to be carbonicolous. So far, only four species of Lyophyllum (L. ulmarium, L. leucocephalum, L. ambustum, and L. subnigricans) have been reported from India (Manjula 1983). Of these, L. ulmarium and L. leucocephalum have now been transferred to Hypsizygus (as H. ulmarius) and Tricholomella (as T. constricta) respectively of the family Lyophyllaceae. Lyophyllum species have not been described so far in Kerala State of India (Sathe and Daniel 1980; Farook et al. 2013). During the course of our studies on the agarics of Kerala State, we came across an undescribed carbonicolous species of Lyophyllum. It is formally described, illustrated, and discussed here based on both morphology and molecular phylogeny

Species