The species
Pirex concentricus was originally
described by
Mordecai Cubitt Cooke and
Job Bicknell Ellis in 1885 as
Radulum concentricum. Ellis collected the
type specimens from
Oregon. A century after Cooke's publication,
Kurt Hjortstam and
Leif Ryvarden circumscribed the new genus
Pirex to contain this fungus, as they believed it to have a unique combination of
traits that would not adequately fit into any other known genera. The name
Pirex is an
anagram of the fungal genus
Irpex. In 1995, Hjortstam considered
Pirex to be a
synonym of
Pseudolagarobasidium, and proposed the
new combination Pseudolagarobasidium concentricum. Modern
systematics considers the two genera to be distinct;
Pseudolagarobasidium is classified in the family
Phanerochaetaceae. Hjortstam added
Hydnum subvinosum Berk. & Broome to
Pirex in 1987, but this fungus is considered now a species of
Radulodon. ==References==