Amylostereaceae species was for a long time classified in the genus Stereum , based primary on the layered structure of the fruit body and the similar physiological activity . Mycologist Jacques Boidin separated Amylosterum from Stereum in 1958 , justifying this decision by explaining that microscopic differences such as amyloid spores and encrusted cystidia was sufficiently distinct to warrant recognition as a new genus . Although the type species of the genus ( today called A. chailletii ) was initially named Trichocarpus ambiguus , the name Trichocarpus had already been used for a genus in the flowering plant family Malvaceae . Boidin thus chose the genus name Amylostereum , referring to the amyloid spores .