Description:There are over 2000 described species of webcaps in the genus Cortinarius. Their abundance and global distribution make them ideal study subjects for the evolution of fungi. In the first half of this presentation I will talk about truffle-like sequestrate fungi (fungi that have enclosed spore-bearing surfaces) and theories about their evolution. I tested Dr. Harry Thiers’ hypothesis that sequestrate fungi evolved in habitats of low precipitation by correlating the amount of precipitation and the state of being sequestrate. I found that sequestrate Cortinarius species are more likely to be found in areas having a great daily change in temperature and they are more likely to be found in areas that have a seasonal change in precipitation. Reinforcing this observation no sequestrate Cortinarius species have been found in the tropics. Seasonality appears to be important in the evolution of truffle-like fungi. In the second half of this presentation I present the work I did on the taxonomy biogeography and evolution of the beautiful Cortinarius violaceus group. About Emma Harrower:Emma Harrower first became interested in fungi with her first look at ectomycorrhizal root tips through a microscope. The astounding below-ground biodiversity inspired her to take a course in mycology so that she could see the above-ground life-forms. During the course she stumbled across a mushroom that couldn’t be identified macroscopically microscopically or using a DNA Barcode sequence (at that time). She didn’t think it was right to ignore the identity of that mushroom. Four years later she published a paper with Dr. Mary Berbee which estimated the number of Cortinarius species in the province of British Columbia Canada to be more than three times what was previously recorded based on comparing DNA sequences. She went on to study the macromorphology and micromorphology of the Cortinarius violaceus group with Dr. Brandon Matheny at the University of Tennessee Knoxville. Emma is a taxonomist who loves to be out in the field discovering new things. NYMS members will receive an email that includes a link to join the meeting.