Paxillus albidulus, P. ammoniavirescens, and P. validus revisited

Comparison of nrITS sequences of the type specimens of Paxillus ammoniavirescens and P. validus show them to be identical. The name Paxillus ammoniavirescens was published in 'Spring 1999' [northern hemisphere] and that of Paxillus validus in August 1999, making P. ammoniavirescens the correct name for this species. A variant without pigments fits into P. involutus, suggesting that P. albidulus might be an albino variant of any species in the P. involutus complex. Paxillus ammoniavirescens is widespread in Europe and has been introduced in the southern hemisphere; P. obscurosporus is known from China and Europe; and the two taxa in the P. involutus clade are reported from Europe and from North America.