Tales of the unexpected II: two new angiocarpic representatives of Russulaceae (Russulales, Basidiomycota) from tropical Southeast Asia.

The evolution of angiocarpic fruiting bodies has occurred numerous times across Russulaceae (Russulales, Basidiomycota). A unique example of a tropical region with an unusually large number of such sequestrate taxa is the humid rainforests of Sri Lanka. In this paper, we describe two new sequestrate species of Russula subg. Russula from Sri Lanka, Russula botrytigustata sp. nov. and Russula ciceriformis sp. nov., based on molecular phylogenetic analyses and extensive morphological descriptions. A key to all sequestrate Russulaceae known from South and Southeast Asia, including these newly described taxa, is provided. Lastly, the possible adaptive advantages that may explain the high abundance of sequestrate fungi in these rainforests are discussed.