ULTRASTRUCTURE OF SPORE ONTOGENY IN TRICHOPHAEA-BRUNNEA (PEZIZALES)

Trichophaea brunnea is a small, pyrophylic, operculate discomycete wit h hyaline, uniguttulate ascospores and an excipulum fringed with short , brownish, tapering hairs. Most recent literature places the species in Sphaerosporella because of its smooth spherical spores, as opposed to ellipsoid spores of other species of Trichophaea. Ellipsoid-spored species of Trichophaea have both smooth and ornamented ascospores with variable guttulation and other apothecial characters. These differenc es raise questions as to the relationship of T. brunnea to other speci es of Trichophaea. In this article we examine the fine structure of sp ore wall development in T. brunnea to determine if it is comparable to that of ellipsoid-spored species. We found that while early stages of spore ontogeny are similar, there are differences in staining propert ies of the primary wall of three species compared, but wall developmen t in T. brunnea is much like that in the type T. abundans. The pattern of deposition and staining properties of various wall layers support other conclusions that Sphaerasporella should not be recognized as a d istinct genus.