XVI International Botanical Congess
Taxa that have yellow, effused stromata and Acremonium like anamorphs are unusual in Hypocrea because their morphology differs from the more discrete stroma and Trichoderma anamorph of H. rufa, the type. There has been confusion when delimiting taxa with effuse stromata at the species level. Hypocrea citrina var. americana, described as occuring on polypores, was distinguished from H. citrina var. citrina on the basis of ascospore morphology. The globose part ascospores of var. americana are unusual in Hypocrea and clearly distinguish it from var. citrina. It is our hypothesis that var. americana either represents a new species in the H. citrina complex or is a synonym of H. pulvinata.