The Ascus Apex in Lichenized Fungi IV. Baeomyces and Icmadophila in Comparison with Cladonia (Lecanorales) and the Non-Lichenized Leotia (Helotiales)

Abstract

This comparative investigation on ascus fine structure and function substantiates the findings of Chadefaud (1960) and his coworkers indicating a close taxonomic relationship between the Baeomycetaceae and Leotia, a non-lichenized member of the Helotiales, rather than between the Baeomycetaceae and the Cladoniaceae and other members of the Lecanorales. Besides the distinct differences in ascus structure and function, cytological divergences were noted between the Baeomycetaceae and Leotia on one hand, and Cladoniaceae on the other. The occurrence of glycogen in the Baeomycetaceae and Leotia, but not in the Cladoniaceae and other members of the Lecanorineae, and the differences in phycobiont preference and thus in the mycobiont-phycobiont contact in the Baeomycetaceae and Cladoniaceae were discussed.

A Re-Examination of Generic Concepts of Baeomycetoid Lichens Based on Phylogenetic Analyses of Nuclear ssu and Lsu Ribosomal Dna

“…These results challenge the hypotheses of Chadefaud (1960) and Honegger (1983), who predicted a close relationship between Baeomyces and Leotia on the basis of ascus similarities. However, discretion should be used in concluding that the Baeomycetaceae and Icmadophilaceae are not closely related to other members of the Helotiales given die complex and potentially non-monophyletic nature of the order (Pfister 1997).…”

Evolutionary Relationships of Nonsexual Lichenized Fungi: Molecular Phylogenetic Hypotheses for the Genera Siphula and Thamnolia from SSU and LSU rDNA

“…Recently however, the Baeomycetaceae and Icmdophilaceae were accepted as members of the Helotiales (Gierl and Kalb 1993, Rambold et al 1993, Tehler 1996, Hawksworth et al 1995 primarily based on similarities of ascus structure with Leotia (Chadefaud 1960, Honegger 1983. Molecular studies of SSU nrDNA have questioned the placement of either the Baeomycetaceae or the Icmadophilaceae in the Helotiales.…”

Phylogenetic hypotheses: Cladoniaceae, Stereocaulaceae, Baeomycetaceae, and Icmadophilaceae revisited

“…This view was supported by Eriksson & Petterson in ERIKSSON & HAWKSWORTH (1996), with some hesitation. However, affinities of the Baeomycetaceae (Baeomyces) to the Helotiales were noted by DUVIGNEAUD (1944) and LE GAL (1946), and later, this view was supported by CHADEFAUD (1960), HONEGGER (1983), GIERL & KALB (1993), RAMBOLD, TRIEBEL & HERTEL (1993), HAWKSWORTH et al (1995) andTEHLER (1996). Similarly, a closer alliance of "Siphulaceae" (= Icmadophilaceae) with the Helotiales s. lat.…”