Abstract
Sibling species have been demonstrated in Peniophora cinerea, Phlebia lilascens, P. livida, and P. subochracea by the use of incompatibility tests. Here, cultural characters, nuclear behavior, and isoelectric focusing of buffer-soluble mycelial proteins have been used to find differences not seen in fruitbody morphology. The methods used are evaluated and the relationships among the siblings are discussed.