Observations on Gymnoascaceae. I. Myxotrichum Uncinatum and a New Species of Myxotrichum

Abstract

SUMMARY A search of the literature on the Gymnoascaceae has clearly revealed that the descriptions and diagnoses are often inadequate for identification of these fungi. Therefore, an investigation was undertaken to establish sounder bases for classification of the Gymnoascaceae. In an effort to determine whether gametangial morphology might serve as an additional taxonomic character for the separation of species, the morphological development of many species of Gymnoascaceae was examined. The observations on Myxotrichum uncinatum (Eidam) Schroeter and for M. emmonsii, described here as a new species, are reported in this paper. Myxotrichum uncinatum possesses gametangia which are similar in appearance in the early stages. This is not in accord with what Eidam has reported. The gametangia of M. emmonsii consist of a central club-shaped antheridium which becomes encircled several times by a more slender ascogonium. In both species croziers are formed prior to formation of asci. Indications are that croziers are formed in all species of the family and may be looked upon as a characteristic of some phylogenetic significance in establishing the relationship of the Gymnoascaceae among the lower Ascomycetes.