Characterization of New Tropicoporus Species (Basidiomycota, Hymenochaetales, Hymenochaetaceae) Discovered in Tamil Nadu, India.

This study aimed to investigate the morphological characteristics and phylogenetic relationships of three new species of Tropicoporus from the southern parts of India. The analyses of the ITS and nLSU regions revealed the novelty of these species, which have been named T. pannaensis, T. subindicus, and T. xerophyticus. All three species possess pileate basidiomes, a monomitic hyphal system in the context, and the presence of cystidioles and setae. However, they differ significantly in their phylogenetic placements and other morpho-taxonomic features. Tropicoporus pannaensis is characterized by a meagrely ungulate basidiome, indistinct zones, and an obtuse margin. Tropicoporus subindicus has a triquetrous basidiome and a radially cracked, crusted pileal surface with an acute margin, while T. xerophyticus is distinguished by an imbricate, perennial basidiome with an abundantly warted pileal surface. A phylogenetic tree is provided to show the placement of the three new species, along with detailed descriptions and illustrations. Additionally, a key for the identification of the Asian species of Tropicoporus is presented.