Morphological and molecular characterization of two novel species of Agaricus section Xanthodermatei

Abstract

Agaricus specimens collected in France belong to two novel entities resembling small forms of A. moelleri and A. xanthodermus, two common species in section Xanthodermatei. Molecular (IT1+ITS2 DNA sequence) and morphological comparisons between eight presumed similar taxa of the section support the elevation of both entities to species rank. The new entities are described as A. parvitigrinus and A. xanthodermulus. They form a group with A. laskibarii, a rare species also recently described from France, and A. californicus, a North-American species. The well known A. moelleri and A. xanthodermus are the most related species among the studied sample. Like other species of the section, both new species have a phenolic odor and are probably toxic.

• Basidiomycetes
• Agaricus
• section Xanthodermatei
• ITS
• systematics

The authors are grateful to Guy Dupuy for A. xanthodermulus collections, to Magalie Monmarson and Cathy Spataro for technical assistance, to Luis A. Parra and Richard W. Kerrigan for specimens, sequences and useful discussions, to Pascal Hériveau for bibliographic documentation and to Gaston Heuclin for the Latin translation.