Phylogenetic Relationships within Lepiota Sensu Lato Based on Morphological and Molecular Data

Abstract

Current classifications of the light-spored agaric genus Lepiota s. 1. (Agaricaceae, Agaricales) were evaluated using parsimony analyses of morphological and molecular characters. Thirty-eight morphological characters were studied using macroscopic, microscopic, and biochemical analysis of fruit-body, basidiospores, and vegetative cultures. These characters were used in parsimony analysis of 25 species within Lepiota s. 1., which represent a broad sampling within the six key segregate genera recognized by Singer: Lepiota s. s., Cystolepiota, Leucocoprinus, Leucoagaricus, Macrolepiota, and Chlorophyllum. In addition, five other members of the Agaricales were evaluated from Agaricus, Cystoderma, and Ripartitella, as well as two dark-spored allies from Coprinus section Comati and a dark-spored secotioid relative. Additional outgroups were used to evaluate the root of the phylogeny. Morphology-based analyses support the use of the Lepiota segregate genera recognized by Singer that are included in the tribes Lepioteae and Leucocoprineae, with two exceptions: Lepiota section Echinatae is in a clade with Cystolepiota, and Leucoagaricus appears paraphyletic. Molecule-based analyses using both nuclear and mitochondrial rDNA data provide less resolution but support the transfer of Lepiota section Echinatae to Cystolepiota and a paraphyletic Leucoagaricus, as well as a distinct Chlorophyllum.