The Xerulaceae (Basidiomycetes), a family with sarcodimitic tissues

Abstract

The taxonomic value of the presence of sarcodimitic tissues and derived tissues in the agarics was investigated. Basidiomata of only 15 genera of 153 agaric and bolete genera surveyed had sarcodimitic tissues. The family, the Xerulaceae, is recognized for these 15 lamellate, sarcodimitic genera along with 1 genus exhibiting modified tissues and 2 closely allied genera apparently lacking sarcodimitic tissues. It is hypothesized that they evolved convergently and then in parallel with members of the Tricholomataceae. Taxonomic difficulties arising from the apparent loss of the sarcodimitic tissues in evolutionarily advanced taxa within the Xerulaceae, such as Mycena and Xerula, are discussed. Antibiotics with an (E)-β-methoxyacrylate moiety (strobilurins, oudemansin), which are potentially useful against cancer, with one possible exception are found only in a number of genera with sarcodimitic or derived tissues currently assigned to the Xerulaceae. Two new combinations are proposed: Cystolepiota pusillomyces (Peck) comb.nov. and Floccularia albolanaripes (Atk.) comb.nov.