42 Annales Universitatis Paedagogicae Cracoviensis Studia Naturae, 1: 42–51, 2016, ISSN 2543-8832 Svetlana Gáperová1*, Ján Gáper2,3, Terézia Gašparcová1, Kateřina Náplavová3,5, Peter Pristaš4 1 Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01 Banská Bystrica, Slovak Republic, *Svetlana.Gaperova@umb.sk 2 Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, T.G. Masaryka 24, 960 63 Zvolen, Slovak Republic 3 Faculty of Sciences, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic 4 Institute of Biology and Ecology, Faculty of Natural Sciences, Pavol Josef Šafárik University, Moyzesova 11, 040 01 Košice, Slovak Republic 5 CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, Portugal Morphological variability of Fomes fomentarius basidiomata based on literature data Introduction �e genus Fomes is a taxon accepted in the Polyporaceae family of Polyporales order in class Agaricomycetes, subphylum Agaricomycotina and phylum Basidiomycota. Fomes fomentarius is the type species of the genus (Donk, 1960). �ere are two mor- phological species in the genus Fomes recognized at present: F. fomentarius (L.) Fr. and F. fasciatus (Sw.) Cooke (Ryvarden, 1991). Although only mean basidiospore size is a helpful morphological characteristic in identi�cation of the respective species, ITS and rpb2 sequence data and optimum temperature for hyphal growth in vitro, support separation of these two distinct species (McCormick et al., 2013a; Gáper et al., 2016). F. fomentarius is an ecologically and economically important polypore wood decay macrofungus with major roles not only in nutrient cycling in forest ecosystems as decomposer of dead wood and plant litter, but also as a source of medicinal and nutra- ceutical products (Tello et al., 2005; Collado et al., 2007; Neifar et al., 2013; Dresch et al., 2015). �ere have also been reports that it can persist as an endophyte in healthy plants for many years (Baum et al., 2003; Par�tt et al., 2010). �e species has been reported from Africa, Asia, Europe, South America (Chile) and North America (Mc- Cormick et al., 2013a, b; Gáper, Gáperová, 2014), but a revision of the F. fomentarius data from Chile is necessary (Gáper et al., 2016). In recent years, the existence of three distinct ITS lineages/sublineages among F. fomentarius strains has been clearly established. �e sublineage A1 consists of strains isolated from North America, whereas the sublineage A2 consists of strains recently 43 isolated only from Europe. �e lineage B consists of strains isolated from Europe and Asia (Gáper et al., 2016). �e presence of the two variable groups in Europe was further con�rmed by molecular methods based on both efa region and LSU gene se- quences comparison, so the F. fomentarius actually includes two sympatric cryptic species in Europe (Pristaš et al., 2013). �e present paper reviews the morphological variability of the F. fomentarius ba- sidiomata with implications for reliable separation of F. fomentarius lineages/sublin- eages, basing on descriptions published in the literature. In contrast to the strain data (Dresch et al., 2015; Gáper et al., 2016), the morphological variability of F. fomentarius basidiomata is well documented. Methods All reliable information on F. fomentarius basidiomata was collected and corroborated through the evaluation of literature in libraries and searches in online databases using Google Scholar, SciFinder and Web of Knowledge. In this article, we present only a small fraction of the literature on the species within North America, namely McCor- mick et al. (2013a, b) because basidiomata morphology of F. fomentarius examined in their studies are consistent with formerly published descriptions (Overholts, 1953; Lowe, 1957; Gilbertson, Ryvarden, 1986). �ey examined macro- and micromorpho- logical characters of basidiomata sampled from multiple woody plant hosts and geo- graphic regions in the United States (McCormick et al., 2013a, b). Results and discussion General description of basidiomata MACROCHARACTERS: basidiomata (Fig. 1) perennial, sessile, ungulate (occa- sionally applanate or triquetrous), tough, woody with a blunt margin; upper surface of pileus crustose, glabrous, prominently zoned (occasionally slightly zonate or no zonation) and shallowly furrowed, marginal part �nely tomentose or smooth; pore surface concave (occasionally �at to slightly concave or convex); pores round, small (2–5 per mm); context pale brown, so�-corky, tough and �brous, azonate or concen- trically zoned, up to 1–3 cm thick; granular core of varying size developing at upper part of the context close to the substratum consisting of very thick-walled and irreg- ularly shaped hyphae (sclerids); tube layers not distinctly (exceptionally distinctly) strati�ed, brown and becoming �lled with white mycelium. MICROCHARACTERS: hyphal system trimitic; contextual generative hyphae thin-walled, hyaline with clamps, 2–5 µm in diam., inconspicuous; contextual sket- etal hyphae thick-walled, aseptate, pale brown in KOH, 3–8 µm in diam.; contextual M orphological variability of Fom es fom entarius basidiom ata based on literature data S ve tla na G áp er ov á, J án G áp er , T er éz ia G aš pa rc ov á, K at eř in a N áp la vo vá , P et er P ris ta š 44 binding hyphae thick-walled, strongly branched, aseptate, pale brown, 1.5–4.5 µm in diam. Cystidia none, cystidioles o�en present in the hymenium, thin-walled, fusoid, 24–40×3.5–7.5 µm, with a  basal clamp. Basidia clavate, 4-sterigmate, usually with a  basal clamp, developed only early in the spring. Basidiospores cylindric, hyaline, smooth, negative in Melzer’s reagent. Geographic variability of basidiomata Above mentioned characters from basidioma macro- and micromorphology basically follow the description given by Ryvarden and Gilbertson (Gilbertson, Ryvarden, 1986; Ryvarden, Gilbertson, 1993). �ey generally correspond well with those reported in other comprehensive polyporological monographs and recent studies, but we detected some di�erences. On the other hand, some European and Asian data is identical (Ry- varden, Gilbertson, 1993; Nuñez, Ryvarden, 2001) (Tab. 1). As described in Tab. 1, basidiomata pileus and pore surface colours, basidioma size, depth of tube layer and basidiospore size are the most variable characters within species. It seems that pileus surface colour in Europe is generally of lighter tones in comparison with basidiomata found in North America and Asia. �e same pattern ap- pears in pore surface colours, basidiomata from Europe are generally of lighter tones. �e basidiomata width is 15 cm in North America and up to 40 cm in Asia, on the other hand, it may reach up to 50 cm in Europe. Maximum depth of tube layer is 8 mm in Europe and up to 10 mm in North America, in Asia it varies from 2 to 16 mm and in Fig. 1. Fomes fomentarius basidiomata typically ungulate in shape on beech (Fagus sylvatica) trunk. From M. Šebesta (unpub., 2015) 45 Europe it varies from 2 to 10 mm (Jülich, 1984; Breitenbach, Kränzlin, 1986; Gilbert- son, Ryvarden, 1986; Zhao, Zhang, 1992; Ryvarden, Gilbertson, 1993; Bondartseva, 1998; Nuñez, Ryvarden, 2001; Bernicchia, 2005; McCormick, 2013a; Prasher, 2015). Tab. 1. Geographic variation in macro- and micromorphological traits of the Fomes fomentarius basidioma Pileus surface colour Europe: older party gray, marginal part light brown1,2; older party gray, blackish, yellowish or yellowish brown; marginal part light reddish brown3, silvery white, grayish, gray-brown to nearly black4; ocher to red brown when young, later light to dark gray5; brown when young, later grayish brown and gray6 Asia: older party gray, marginal part light brown7; older party gray, blackish, yellowish or yellowish brown; marginal part light reddish brown3, gray, gray-brown to black8; gray, grayish brown, grayish black9 North America: brownish gray to nearly black10; gray, brown, blackish gray, cinnamon, bu�11 Pore surface colour Europe: pale brown1,3 to pale gray3; cream coloured when young, then light ocher to brownish5,6; ochra- ceous to gray2 Asia: pale brown1,3 to pale gray3; brownish to brown or black brown to black8; light brown to grayish brown9 North America: brown to grayish brown10; bu�, brown, cinnamon11 Basidioma size: width × height [cm] Europe: up to 15 wide1; up to 20–40×5–15 (-20)3; 10–25 (-30)×15–205; up to 30–40 wide2; 5–50×3–256 Asia: up to 15 wide7; up to 20–40×5–15 (-20)3; 3–20 (-40)×2–15 (-27)8; up to 12×189 North America: 2–15 wide10 Depth of tube layer [mm] Europe: 2–63; 2–5 (-8)5; 5–72; ca. 106 Asia: 2–63,8 up to 168; 79; North America: up to 1010 Basidia size [µm] Europe: 23–25×7–91; 25–30×8–113; 21–25×7–92; 20–30×7–105; 25–30×8–116 Asia: 23–25×7–97; 25–30×8–113 Basidiospore size [µm] Europe: 12–18 (-20)×4–71; 15–20×5–73; 18.5–19×5.5–65; 14–20×4.5–6.52; 6–24×5.5–6.56 Asia: 12–18 (-20)×4–77; 15–20×5–73; 12–19×5–6.5 (-8.5)8; 15.6–18.6×5.1–6.19 North America: 12–18×4–710; 10–21.25×2.5–7.511 1 Ryvarden, Gilbertson, 1993; 2 Bernicchia, 2005; 3 Bondartseva, 1998; 4 Schwarze, 1992; 5 Breitenbach, Kränzlin, 1986; 6 Jülich, 1984; 7 Nuñez, Ryvarden, 2001; 8 Zhao, Zhang, 1992; 9 Prasher, 2015; 10 Gilbertson, Ryvarden, 1986; 11 McCormick, 2013a Concerning microscopic features, there are no signi�cant di�erences in the size of basidia in Europe and Asia. Length of basidiospores from Asia is not less than 12 µm. Maximum width of basidiospores is up to 7 µm in Europe, whereas basidiospores found in North America and Asia may have up to 7.5 µm and 8.5 µm respectively (Jülich, 1984; Breitenbach, Kränzlin, 1986; Gilbertson, Ryvarden, 1986; Zhao, Zhang, 1992; Ryvarden, Gilbertson, 1993; Bondartseva, 1998; Nuñez, Ryvarden, 2001; Bernic- chia, 2005; McCormick, 2013a; Prasher, 2015). M orphological variability of Fom es fom entarius basidiom ata based on literature data S ve tla na G áp er ov á, J án G áp er , T er éz ia G aš pa rc ov á, K at eř in a N áp la vo vá , P et er P ris ta š 46 According to Schwarze (1992) within the geographical area of distribution in Eu- rope, the colouration, size and shape of the basidioma can vary based on where the specimen has grown. �e colour of the pileus surface ranges from silvery white to nearly black although when it is wet it can appear to be black and when it is old and dry it can be bleached to an o�-white colour. �e colour is lighter at lower latitudes, at low elevations and on the south side of stems. Despite his studies covered basidio- carps collected in di�erent places of origin in Great Britain and in mainland Europe, they revealed no discernible pattern (Schwarze, 1994). �ese di�erences have caused some fungal taxonomists to propose infraspeci�c divisions. �us, the black basidiomata were previously classi�ed as a Fomes nigrescens, Ungulina fomentaria subsp. nigricans, F. fomentarius subsp. nigricans, or F. fomentarius var. nigrescens. �e lighter coloured basidiomata were classi�ed as a F. fomentarius subsp. fomentarius. According to Zhao, Zhang’s interpretation of the Chinese specimens examined, the basidiospores are also di�erent; in F. fomentarius subsp. nigricans they are ovoid to subglobose (9–11×6.5– 6.8 µm), while in F. fomentarius subsp. fomentarius they are cylindrical to oblong el- lipsoid (12–19×5–6.5 µm) (Zhao, Zhang, 1992). Similarly, the small basidiomata with closely concentrically zoned pileus surfaces associated with birches were previous- ly classi�ed as a  Polyporus fomentarius var. lineatus (Velenovský, 1922). In addition, there are a  number of taxonomic synonyms, in the past described as separate taxa. Basidiomata of F. fomentarius can range in size from ca. 5 to ca. 50 cm (Tab. 1). The species have been observed in northern Japan (Hokkaido Island) and northe- astern China (Changbai Shan Nature Reserve; Xiao Xing’anling Mts.) to have two morphologically different types basing on basidioma size (Cheng, 2000). While the small-sized basidiomata (up to 20 cm wide) seem to be linked preferably with Betula spp., less frequently with Populus sp. and Acer sp., as the hosts, the large-sized basi- diomata (over 20 cm wide) were found mostly on Acer sp., Tilia amurensis, Quercus liaoi and less frequently Fraxinus mandshurica, Ulmus sp. and Betula platyphylla (beeches are not distributed either in Hokkaido, or in the Changbai Shan Nature Re- serve) (Cheng, 2000). Two types of F. fomentarius have also been reported from an old-growth beech (Fagus japonica, F. crenata) and oak (Quercus serrata, Q. mon- golica) forest in a cool temperate area of Japan in the southern part of the Abukuma Mts. along the Pacific coast. Both types occurred frequently on beeches (Yamashita et al., 2010). The two types of F. fomentarius basidiomata were found growing together in the various localities (Cheng, 2000; Yamashita et al., 2010). These data correspond well with those reported in the Japanese polyporological monographs (Imazeki, Hon- go, 1989; Igarashi, 1989, 1994; Takahashi, 2003). Apart from size, basidiomata may range also in shape. According to Gaudreau and co-authors it is either bracket- or boot-shaped (Gaudreau et al., 2005). The boot shaped form, however, is probably related to the following phenomenon. If a tree that F. fomentarius is growing on falls 47 down, the fungus will re-orient its direction of growth to account for its changed po- sition, so specimens are sometimes seen with two different patterns of growth in the basidioma, at right angles to each other. This is to ensure that the fertile underside is always aligned with gravity so the basidiospores will fall into the air currents. Accor- ding to Læssøe and Del Conte (1996) this species in Europe exists in two forms, the beech and the birch form, depending on the host. Beech form is semicircle-shaped and brown. Birch form is hoof-shaped, more slender and darker gray (Læssøe, Del Conte, 1996). The two forms have been already recognized by Lloyd in the early 20th century (Lloyd, 1915). According to this author, both forms are hoof-shaped. Beech form is larger with soft context and occurs in France. Birch form is smaller with harder context and occurs in the USA and Northern Europe (Lloyd, 1915). However, morphological analyses of 1 165 basidiomata samples within the Malenovický kotel nature reserve (Beskydy Mts., the Czech Republic) using the General Linear Model (GLM) confirmed a direct relationship between the shape of basidioma and its age rather than the host. The approximate age of transition of the basidiomata from the birch form to the beech form was around 5–6 years (Rybovičová, 2010). But some of the existing above mentioned phenotypic differences can be based on the interac- tions between the genotype and environment (Schwarze, 1999, 2004) and/or presence of different lineages/sublineages (Gáper et al., 2016). However, no clear differences between basidiomata, useful for reliable separation of the lineages/sublineages, have been observed so far. Nevertheless, a recent F. fomentarius basidiomata description in North American research articles (McCormick et al., 2013a, b) represents North American A1 sublineage (Gáper et al., 2016). Basidiomata of the F. fomentarius su- blineage A1 are ungulate, applanate or triquetros; pileus surfaces gray, brown, blacki- sh gray, cinnamon, buff; pore surfaces buff, brown, cinnamon, concave, flat to slightly concave or convex; pores 2–5 per mm; basidiospores 17.54(±0.05)×5.27(±0.03) µm (mean ±SE) and ranged from 10.0–21.25×2.5–7.5 µm. Colorus of external portions of the basidiomata (pileus and pore surface colours) are more variable than internal portions (context and tube layers) (McCormick et al., 2013a). In both Asian and Eu- ropean literature such data is absent. As regards then, European literature alone, it is most possible that these descriptions are based on basidiomata of two other lineages/ sublineages and thus we cannot discriminate between them. Conclusions �e analysis of data present in literature shows that no clear di�erences can be ob- served between basidiomata of Fomes fomentarius which would be suitable for relia- ble separation of lineages/sublineages. Within geographical area of distribution in the world, these characteristics can vary considerably. �e existing phenotypic di�erences M orphological variability of Fom es fom entarius basidiom ata based on literature data S ve tla na G áp er ov á, J án G áp er , T er éz ia G aš pa rc ov á, K at eř in a N áp la vo vá , P et er P ris ta š 48 in F. fomentarius basidiomata morphology can be attributed either to di�erent line- ages/sublineages, or to interactions between the genotype and its environment. �e phenotypic basidioma traits of the North American A1 sublineage are known. However, it is most possible that the descriptions in European literature are based on basidiomata of both sublineage A2 and lineage B, and thus we cannot discriminate between them. Moreover, some European and Asian macro- and microcharacters are identical. �erefore, the following recommendations which would be suitable for reliable separation of the lineages/sublineages can be made based on the review: 1. basidiomata di�er macromorphologically mainly in pileus and pore surface col- ours, basidioma size and depth of tube layer, 2. basidiomata di�er micromorphologically mainly in basidiospore size, 3. a detailed study of each of these three attributes, especially within Europe and Asia, would be suitable for separation of the above mentioned lineages/sublineages. Acknowledgments �is work has been supported by grants from the Scienti�c Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic (VEGA No. 1/0286/17 and KEGA No. 025UMB-4/2017) and the project SGS 16/PřF/2016 from the Faculty of Sciences of the University of Ostrava (Czech Republic). We wish to ac- knowledge the anonymous reviewers for their detailed and helpful comments on the manuscript. References Baum, S., Sieber, T.N., Schwarze, F.W.M.R., Fink, S. (2003). Latent infections of Fomes fomentarius in the xylem of European beech (Fagus sylvatica). Mycological Progress, 2(2), 141–148. DOI: 10.1007/ s11557-006-0052-5 Bernicchia, A. (2005). Polyporaceae s.l. Fungi Europaei. Alassio: Massimo Candusso. Bondartseva, M.A. (1998). De�nitorium fungorum rossiae. Ordo Aphyllophorales. Saint Petersburg: Nau- ka. [In Russian] Breitenbach, J., Kränzlin, F. (1986). Fungi of Switzerland. Non gilled fungi. Heterobasidiomycetes, Aphyllo- phorales, Gastromycetes. Lucerne: Mykologia Verlag. Cheng, D.S., Yamaguchi, T., Wang, Z.J., Pan, X.R. (2000). Genetic di�erentiation between two morpho- logical types of Fomes fomentarius based on isozyme analysis. Mycosystema, 19(1), 81–86. Collado, J., Platas, G., Paulus, B., Bills, G.F. (2007). High-throughput culturing of fungi from plant litter by a dilution-to-extinction technique. FEMS Microbiology Ecology, 60(3), 521–533. DOI: 10.1111/j. 1574-6941.2007.00294.x Donk, M.A. (1960). �e generic name proposed for Polyporaceae. Persoonia, 1(2), 173–302. Dresch, P., Aguanno, M.N., Rosam, K., Grienke, U., Rollinger, J.M., Peintner, U. (2015). Fungal strain matters: colony growth and bioactivity of the European medicinal polypores Fomes fomentarius, Fo- mitopsis pinicola and Piptoporus betulinus. AMB Express, 5(1), 4. DOI: 10.1186/s13568-014-0093-0 Gáper, J., Gáperová, S. (2014). a worldwide geographical distribution and host preferences of Fomes fo- mentarius. In: M. Barta, P. Ferus (eds.), Dendrological Days in Mlyňany Arboretum SAS 2014. Vieska nad Žitavou: Mlyňany Arboretum SAS, 57–63. 49 Gáper, J., Gáperová, S., Pristaš, P., Náplavová, K. (2016). Medicinal Value and Taxonomy of the Tinder Polypore, Fomes fomentarius (Agaricomycetes): A Review. International Journal of Medicinal Mush- rooms, 18(10), 851–859. DOI: 10.1615/IntJMedMushrooms.v18.i10.10 Gaudreau, G., Ribordy, A., Ribordy, F.-X., Tremblay, M. (2005). Fomes fomentarius. In: M. Tremblay, S. Lafortune, P. Sawyer (eds.), Proceedings of the 11th Conference of Scienti�c Knowledge. Sudbury: Ac- fas-Sudbury Université Laurentienne, 195–204. Gilbertson, R.L., Ryvarden, L. (1986). North American polypores. Abortiporus-Lindtneria. Oslo: Fungi- �ora Press. Igarashi, T. (1989). Fungi of Hokkaido. Sapporo: Hokkaido Shinbunsha. Igarashi, T. (1994). Continuation of the fungi of Hokkaido. Sapporo: Hokkaido Shinbunsha. Imazeki, R., Hongo, T. (1989). Colored illustrations of mushrooms of Japan. Osaka: Hoikusha. Júdová, J., Dubíková, K., Gáperová, S., Gáper, J., Pristaš, P. (2012). �e occurrence and rapid discrimina- tion of Fomes fomentarius genotypes by ITS-RFLP analysis. Fungal Biology, 116(1), 155–160. DOI: 10.1016/j.funbio.2011.10.010 Jülich, W. (1984). Aphyllophorales, Heterobasidiomycetes, Gastromycetes. In: H. Gams (ed.), Kleine Kryptogamen�ora IIb/1. Jena: Gustav Fischer Verlag. Læssøe, T., Del Conte, A. (1996). �e Mushroom Book. London: Dorling Kindersley. Lloyd, C.G. (1915). Synopsis of the genus Fomes. Cincinnati: Lloyd. Lowe, J.L. (1957). Polyporaceae of North America. �e genus Fomes. Technical publications. Syracuse: New York State College of Forestry. McCormick, A.M., Grand, F.L., Post, B.J., Cubeta, A.M. (2013a). Phylogenetic and phenotypic character- ization of Fomes fasciatus and Fomes fomentarius in the United States. Mycologia, 105(6), 1524– 1534. DOI: 10.3852/12-336 McCormick, A.M., Cubeta, A.M., Grand, F.L. (2013b). Geography and hosts of the wood decay fungi Fomes fasciatus and Fomes fomentarius in the United States. North American Fungi, 8, 1–53. DOI: 10.2509/naf2013.008.002 Neifar, M., Jaouani, A., Chaabouni, S.E. (2013). �e potent Pharmacological Mushroom Fomes fomen- tarius. Cultivation Processes and Biotechnological Uses. In: K.V. Gupta, M. Schmoll, M.A. Mazutti, M. Mäki, G.M. Tuohy (eds.), Applications of Microbial Engineering. Boca Raton: CRC Press Taylor & Francis Group, 300–322. Nuñez, M., Ryvarden, L. (2001). East Asian polypores. Polyporaceae s. lato. Synopsis Fungorum, 14(2), 170–522. Overholts, L.O. (1953). �e Polyporaceae of the United States, Alaska and Canada. Ann Arbor: �e Uni- versity of Michigan Press. Par�tt, D., Hunt, J., Dockrell, D., Rogers, H.J., Boddy, L. (2010). Do all trees carry the seeds of their own destruction? PCR reveals numerous wood decay fungi latently present in sapwood of a wide range of angiosperm trees. Fungal Ecology, 3(4), 338–346. DOI: 10.1016/j.funeco.2010.02.001 Prasher, I.B. (2015). Wood-rotting non-gilled Agaricomycetes of Himalayas. Dordrecht: Springer. Pristaš, P., Gáperová, S., Gáper, J., Júdová, J. (2013). Genetic variability in Fomes fomentarius recon�rmed by translation elongation factor 1 alpha DNA sequences and 25S LSU rRNA sequences. Biologia, 68(5), DOI: 10.2478/s11756-013-0228-9 Rybovičová, B. (2010). Opravdu existuje březová a  buková forma choroše Fomes fomentarius? In: R.   Maršálek (ed.), SVK, Sborník recenzovaných příspěvků kategorie Věda má budoucnost. Ostrava: Ostravská univerzita v Ostravě, 59–61. [In Czech] Ryvarden, L. (1991). Genera of polypores. Nomenclature and taxonomy. Synopsis Fungorum, 5, 1–373. M orphological variability of Fom es fom entarius basidiom ata based on literature data S ve tla na G áp er ov á, J án G áp er , T er éz ia G aš pa rc ov á, K at eř in a N áp la vo vá , P et er P ris ta š 50 Ryvarden, L., Gilbertson, R.L. (1993). European polypores. Part 1. Synopsis Fungorum, 6, 1–387. Schwarze, F.W.M.R., Engels, J., Mattheck, C. (1999). Holzzersetzende Pilze in Bäumen-Strategien der Holz- zersetzung. Freiburg: Rombach Verlag. Schwarze, F.W.M.R. (1992). Intraspeci�c variation in Fomes fomentarius from Great Britain and the Euro- pean continent. Reading: University of Reading. Schwarze, F.W.M.R. (1994). Wood rotting fungi: Fomes fomentarius (L.: Fr.) Fr. Mycologist, 8(3), 131–133. DOI: 10.1016/S0269-915X(09)80679-4 Schwarze, F.W.M.R., Engels, J., Mattheck, C. (2004). Fungal strategies of wood decay in trees. Heidelberg: Springer. Takahashi, I. (2003). Fungi in Hokkaido. Sapporo: Arisusha. Tello, M.L., Tomalak, M., Siwecki, R., Gáper, J., Motta, E., Mateo-Sagasta, E. (2005). Biotic urban growing conditions-threats, pests and diseases. In: C.C. Konijnendijk, K. Nilsson, T.B. Randrup, J. Schipperijn (eds.), Urban forests and trees. Berlin–Heidelberg–New York: Springer, 327–365. Velenovský, J. (1992). České houby. Praha: Česká botanická společnost v Praze. [In Czech] Yamashita, S., Hattori, T., Abe, H. (2010). Host preference and species richness of wood-inhabiting aphyl- lophoraceous fungi in a cool temperate of Japan. Mycologia, 102(1), 11–19. DOI: 10.3852/09-008 Zhao, J.D., Zhang, X.Q. (1992). �e polypores of China. Bibliotheca Mycologica, 145, 1–524. Abstract Currently two morphological species of the genus Fomes (Polyporaceae, Basidiomycota) are known: F. fo- mentarius (L.) Fr. and F. fasciatus (Sw.) Cooke. Both species are very important in the decomposition of wood and in the nutrient cycling in forest ecosystems. Moreover, F. fomentarius is also known as a source of medicinal and nutraceutical products. Recently the existence of three separate ITS lineages/sublineages among F. fomentarius strains has been clearly established – A1 (the strains isolated from North America), A2 (only from Europe) and B (from Europe and Asia). In this review the current knowledge of the morpho- logical variability of F. fomentarius basidiomata has been summarized in respect of the reliable separation of its lineages/sublineages. Micro- and macrofeatures and geographic variability of the basidiomata have been described. Morphological traits of the F. fomentarius basidiomata can vary due to geographical distribution. �ese phenotypic di�erences can be based on the presence of several groups or interactions between the genotype and environment. However, no clear di�erences between basidiomata, useful for reliable separa- tion of the lineages/sublineages, have been observed so far. A recent description in North American Fomes research articles is based on basidiomata of the A1 sublineage. It is most possible that the descriptions in European literature are based on basidiomata of two other lineages/sublineages and thus we cannot dis- criminate between them. In the future a  detailed study of the macro- and microtraits – pileus and pore surface colors, basidioma size, depth of tube layer, and basidiospore size – is therefore proposed for reliable separation of the lineages/sublineages of F. fomentarius. Key words: basidioma, cryptic species, morphological variability Received: [2016.05.16] Accepted: [2016.09.21] Zmienność morfologiczna owocników Fomes fomentarius na podstawie danych z literatury Streszczenie Obecnie znane są dwa morfologiczne gatunki z rodzaju hubiak Fomes (Fr.) Fr. (Polyporaceae, Ba- sidiomycota): F. fomentarius (L.) Fr. i F. fasciatus (Sw.) Cooke. Obydwa są bardzo ważne w proce- sie rozkładu drewna oraz w obiegu składników pokarmowych w ekosystemach leśnych. Ponadto, 51 F. fomentarius jest również uznany jako źródło produktów leczniczych i nutraceutycznych. Ostat- nio zostało wyraźnie określone istnienie trzech odrębnych linii rozwojowych ITS/sublinii pomię- dzy szczepami F. fomentarius – A1 (szczepy wyizolowane w Ameryce Północnej), A2 (tylko w Europie) i B (w Europie i Azji). W niniejszym przeglądzie aktualna wiedza o zmienności mor- fologicznej owocników F. fomentarius została zebrana w odniesieniu do rzetelnego wydzielenia linii rozwojowych/sublinii. Zostały tu opisane mikro- i makrocechy oraz zmienność geogra�cz- na owocników. Cechy morfologiczne owocników F. fomentarius mogą się różnić ze względu na rozmieszczenie geogra�czne. Różnice fenotypowe mogą bazować na obecności różnych grup lub interakcji pomiędzy genotypem a  środowiskiem. Jednakże nie ma wyraźnych różnic między owocnikami, przydatnych do niezawodnego oddzielenia linii rozwojowych/sublinii, które do tej pory obserwowano. Nowsze opisy gatunków z rodzaju Fomes w Ameryce Północnej w artyku- łach naukowych opierają się na owocnikach z sublinii A1. Jest bardzo prawdopodobne, że opisy w literaturze europejskiej oparte są na owocnikach dwóch pozostałych linii rozwojowych/sublinii, a  zatem nie możemy odróżniać ich między sobą. W przyszłości proponuje się do niezawodnego oddzielenia linii rozwojowych/sublinii F. fomentarius szczegółowe badania makro- i mikrocech: kolorów kapelusza i powierzchni porów, rozmiaru owocnika, głębokości warstwy rurek i rozmiaru bazydiospor. Słowa kluczowe: zróżnicowanie morfologiczne, gatunki kryptyczne, owocnik Information on the authors Svetlana Gáperová She is the member of Department of Biology and Ecology of Faculty of Natural Sciences of Matej Bel Uni- versity in Banská Bystrica (Slovakia). She is interested in the biology and ecology of both woody plants and wood-decaying fungi in urban areas and monitoring of urban air pollution. Ján Gáper He is the member of Department of Biology and General Ecology of Faculty of Ecology and Environ- mental Sciences of Technical University in Zvolen (Slovakia), as well as the member of Department of Biology and Ecology in Faculty of Natural Sciences at University of Ostrava in Ostrava (Czech Republic). He is interested in the identi�cation and ecology of wood-decaying polypores, regarding the importance for ecosystem functioning. Terézia Gašparcová She is an internal PhD student at Faculty of Natural Sciences of Matej Bel University in Banská Bystrica (Slovakia), Department of Biology and Ecology, in study program “Evolution of ecosystems and their protection”. �e topic of her dissertation is “Diversity and distribution of the genus Ganoderma in Slo- vakia”. Kateřina Náplavová She is an internal PhD student in Faculty of Sciences at University of Ostrava (Czech Republic), Depart- ment of Biology and Ecology in study program Biology. �e topic of her dissertation is “Diversity and distribution of wood-decaying polypores”. Peter Pristaš He is the Head of Department of Microbiology in Institute of Biology and Ecology of Faculty of Natural Sciences at Pavol Josef Šafárik University in Košice (Slovakia). He is interested in the molecular phylo- geny and identi�cation of wide spectrum of microorganisms including bacteria, protozoa and fungi. M orphological variability of Fom es fom entarius basidiom ata based on literature data