New and rare taxa in Agaricus section Bivelares (Duploannulati)

Abstract

Ongoing field and laboratory studies have led to our recognition of new taxa in Agaricus section Bivelares, a recent combination and now the earliest synonym and correct name of section Duploannulati. Agaricus cupressophilus and A. tlaxcalensis, in the new Agaricus subsection Cupressorum, and A. agrinferus, A. devoniensis subsp. bridghamii, and A. subsubensis in Agaricus subsection Hortenses, are described. Agaricus subfloccosus is lectotypified. Phylogeny reconstruction methods with ITS1+2 DNA sequences were used to determine appropriate placements of the new taxa. Collectively these new taxa and phylogenetic associations represent a substantial augmentation and clarification of our knowledge of section Bivelares; described, sequenced species-level taxa in the northern hemisphere are increased from six to 10, a distinct subsectional lineage is revealed and infraspecific resolution within A. devoniensis is improved. An anomalous ITS1+2 sequence is documented in one collection of A. subsubensis. Preliminary data on another novel member of Bivelares from France also are provided. Several of these taxa are rare, highlighting opportunities and challenges for documenting biodiversity in this group. Additional comments on related taxa treated in recentPUBLICations are also provided.

• button mushroom
• cultivation
• Cupressus
• ITS sequence evolution
• phylogeny
• taxonomy

We thank D. Arora, P. Arrillaga, P. Boisselet, A. Caballero, K. Chadwick, M. Contu, J. Guinberteau, G. Maddalena, G. Mata, A.D. Mitchell, M. Moinard, D. Murietta, A. Mua, C. Ovrebo, K. Peterson, G. Pickett, S. Rextoueix, M. Shaw, J. Sparks, F. Stevens and A. Tancrède, and the Colorado Mycological Society, for specimens, cultures and/or collecting assistance. J. Guinberteau provided Fig. 3 and other assistance. Advice on Latin and translations were provided by G. Heuclin, R. Halling and J. Santos. Some sequences were kindly provided by M. Challen and J.-P. Xu. P. Callac acknowledges ECOS-Nord and ANUIES (M06A01 Franco-Mexican program) and the BRG (Bureau des Ressources Génétiques, program No. 51, 2007/2008) for financial support.