As part of a biosystematic study of the Lentinellus ursinus species complex
in eastern North America, field and herbarium specimens from North America
, Central America, and Europe were examined. Crossing single basidiospore i
solates demonstrated tetrapolar (bifactorial) mating systems. Three biologi
cal species are recognized as L. ursinus, L. angustifolius, and L. vulpinus
. The production of gloeocystidia and/or chlamydospores is considered taxon
omically significant for identifying somatic cultures of these species. All
three taxa produced laccase, tyrosinase, and peroxidase in culture and are
white-rot fungi. This is the first confirmed report of L. angustifolius fr
om North America.