Ascomycetes on bryophytes: systematics and biology
Bryophilous ascomycetes are ecologically defined as lichenicolous, coprophilous or marine fungi. The only common character they share is their occurrence on bryophytes. Hepaticolous fungi infect both thallose and foliose hepatics, while muscicolous species infect mosses. More specific terms are sometimes used for the parasites of some well-known and frequently infected taxa, e.g. frullaniicolous species occur on Frullania, sphagnicolous species on Sphagnum, and polytrichicolous species on Polytrichaceae. Perianthicolous species attack the developing sporophytes within the perianths of hepatics. Bryophily is a life strategy that has evolved independently in many non-related fungal lineages. Accordingly, bryophilous species represent a heterogeneous assemblage of symbionts of quite different systematic position, mode of nutrition, host selection and geographical distribution. Due to this exceptionally high diversity bryophilous ascomycetes exhibit many characters that are known in other ascomycetes. Bryomycology is the study of these fungi. It provides a plethora of novel fungal taxa, unrecorded hosts, and hitherto unknown characters, such as the formation of intracellular ascomata, leaf-perforating ascomata, unique ascospore types, and subterranean rhizoid galls.