Career
Thiers taught mycology at San Francisco State University for many years, and notable mycologists active as of the 2000s began as his students. He comprehensively revised and expanded on the North American collection of boletes and named many new species. Species authored include:
Boletus amygdalinus
Boletus barrowsii
Boletus dryophilus
Boletus pulcherrimus
Gymnopilus luteoviridis
Leccinum manzanitae
Russula xanthoporphyrea
The genus Chaetothiersia was named in his honor.