**1. Introduction**

Bryophylous or muscicolous fungi can be defined as those that have at least one stage of its life cycle linked to Bryophytes (mosses, liverworts and hornworts). Bryophytes do not produce nutrient-rich storage structures or specialized transport tissues rich in photosynthetic products as vascular plants, but fungal pathogenesis of mosses is being reported with increasing frequency [1]. The relationship between these two

groups is indicated as important to the land colonization by plants [2–4]. Studies of bryophyte/fungal symbioses have also provided powerful insights into the origin and evolution of mycorrhizal associations in land plants [4]. Palaeontologic researchers found fungal structures of Glomeromycota associated with young bryophytes in Ordovician sediments 460 and 400 million years old [5, 6].

Mycorrhizal fungi that inhabit symbiotically healthy tissues of terrestrial plants using organs of absorption [7] inhabiting the rhizoids and/or thalli of liverworts and hornworts were reported associated to different fungi phylla, as Ascomycota, Glomeromycota, and Basidiomycota [4, 8, 9]. Ascomycota has been better studied in this field of knowledge than Basidiomycota [8–11]. Among the Basidiomycota, Agaricomycetes present a total of 19 known orders: Agaricales, Amylocorticiales, Atheliales, Auriculariales, Boletales, Cantharellales, Corticiales, Geastrales, Gloeophyllales, Gomphales, Hymenochaetales, Hysterangiales, Jaapiales, Phallales, Polyporales, Russulales, Sebacinales, Thelephorales, and Trechisporales [12]. With a worldwide distribution, the Agaricomycetes have gained prominence since the class contain several species of economic interest [13–15].

Many of the Agaricomycetes orders are mentioned in different studies about Bryophilous fungi, such as Agaricales, Hymenochaetales, and Polyporales [16–18]. Different structures were developed by fungi to parasite the Bryophytes [1]. Morphological, molecular, and in vitro experiments have shown that mosses such as *Sphagnum*, *Polytrichum* and *Hylochomium* are often associated with Agaricomycetes [16, 17, 19]. A biotrophic trophic mode, in which the fungi species can degrade plant cell walls and lignin, cleaving sucrose to glucose, was recently suggested to occur on 15 species of Hymenochaetales [18].

In Brazil, the are few studies citing the association between Agaricomycetes and Bryophytes [16, 20]. This "gap" in these subjects to science often occurs due to a lack of cooperation between Bryologists and Mycologists [1]. This almost absence of scientific knowledge on this subject is considered as a barrier to better understanding this relation in terms of ecology and taxonomy.

This study as a revision of the knowledge generated up to date to Brazil in this area is an outline of the main employed methods used to identify the interactions of bryophilic mushrooms, as well as a revision of the data of occurrence in the world, and perform a list of Brazilian bryophilous Agaricomycetes. The data presented here are proposed as a starting point to call for more mycologists and bryologists to join the efforts to better understand the Fungi-Bryophyte relationship.
