|Major Groups > Polypores|
Polyporales: The Polypores
[ Basidiomycetes . . . ]
by Michael Kuo
The Polyporales form a large group of diverse mushrooms. Most of these are "polypores" in the widely used sense of the word: they are wood decomposers whose spores are held in tubes--rather like the tubes of the boletes, except that with a very few exceptions the tube layer of a polypore cannot be easily removed as a layer, the way it can with a bolete. Aside from the fact that many of them are attractive and interesting mushrooms, polypores are of special interest to humans because they are wood rotters, assisting in the decomposition of dead wood--and, in many cases, causing rot as pathogens on living wood. Thus the appearance of Laetiporus sulphureus on a living tree, for example, probably signifies the beginning of the end for the tree; inspection of the wood would reveal a reddish brown rot of the heart wood, caused by the mushroom's mycelium.
Taxonomically, the polypores are complicated, and not completely understood. Fifty years ago, when L. O. Overholts' thorough study of polypores in North America (1953) was published, nearly all the species of polypores went under the genus name Polyporus. Today, Polyporus is a comparatively small genus, and many separate genera (and families to hold the genera) have been erected. Current DNA studies shift the polypores around on what seems like a daily basis, and a few have been moved out of the polypore order entirely--like Bondarzewia berkeleyi, which is currently placed in the Russulales. See the page on mushroom taxonomy for the most current portrait of polypore taxonomy.
Identification of polypores is not an insurmountable task--with a few exceptions. Careful analysis of the mushroom's macrofeatures is often sufficient to reach a reasonably secure identification decision. The pore surface of a polypore is often distinctive; for example, Daedaleopsis confragosa has a maze-like pore surface, easily distinguished from the pore surfaces of the many polypores with tiny, round pores. Be sure to pay careful attention to the "host" of your polypore, since identification can sometimes hinge on this information. When polypores grow on living trees, this is a matter of identifying the tree. But the more common scenario involves dead wood--in which case one must make assumptions about what kind of dead wood is involved. Notice, at the very least, whether your mushroom grows in conifer woods or among hardwoods. However, if your mushroom is on a very large stump in the midst of a forest full of small trees, it may take some research or guesswork to determine what kind of tree the stump may represent. Other features often important in the identification of polypores include the reaction of the flesh in KOH, and microscopic features.
I highly recommend Tom Volk's polypore primer for more information on the identification of polypores. Volk is a prominent mycologist who has done significant work with the polypores, including co-authoring the species Laetiporus cincinnatus.
(Incomplete) Key to North American Polypores
I have not yet completed a key to North American polypores, but I have started the ball rolling with a key to the pale-fleshed, stemmed polypores, linked below.
Polypore Sources and Works Cited:
Al-Mughrabi, K. & T. Hsiang (1998). The mating system of Daedaliopsis confragosa. Mycologia 90: 82-84.
Baldrian, P. & Gabriel, J. (2002). Intraspecific variability in growth response to cadmium of the wood-rotting fungus Piptoporus betulinus. Mycologia 94: 428-436.
Binder, M. et al. (2005). The phylogenetic distribution of resupinate forms across the major clades of mushroom-forming fungi (Homobasidiomycetes). Systematics and Biodiversity 3: 1-45.
Blackwell, M. & R. L. Gilbertson (1985). A new species of Inonotus (Aphyllophorales, Hymenochaetaceae) on oak in Louisiana. Mycotaxon 23: 285-290.
Brodie, H. J. (1951). The function of the cups of Polyporus conchifer. Science 114: 636.
Brusis, O. A. (1972). A new species of Fistulina from Mexico. Mycologia 64: 1248-1251.
Burdsall, H. H. (1971). Notes on some lignicolous Basidiomycetes of the southeastern United States. Journal of the Elisha Mitchell Scientific Society 87: 239-245.
Burdsall, H. H. Jr. & Banik, M. T. (2001). The genus Laetiporus in North America. Harvard Papers in Botany 6: 43-55. An online version of this paper can be downloaded here.
Canfield, E. R. & R. L. Gilbertson (1971). Notes on the genus Albatrellus in Arizona. Mycologia 63: 964-971.
Fischer, M. & M. Binder (2004). Species recognition, geographic distribution and host-pathogen relationships: a case study in a group of lignicolous basidiomycetes, Phellinus s.l. Mycologia 96: 799-811.
Gilbertson, R. L. & Burdsall, H. H. Jr. (1972). Phellinus torulosus in North America. Mycologia 64: 1258-1269.
Gilbertson, R. L. (1976). The genus Inonotus (Aphyllophorales: Hymenochaetaceae) in Arizona. Memoirs of the New York Botanical Garden 28: 67-85.
Gilbertson, R. L. (1980). Wood-rotting fungi of North America. Mycologia 72: 1-49.
Gilbertson, R. L. & Ryvarden, L. (1986). North American polypores. Vol. 1. Oslo: Fungiflora.
Gilbertson, R. L. & Ryvarden, L. (1987). North American polypores. Vol. 2. Oslo: Fungiflora.
Gottlieb, A. M., J. E. Wright & J.-M. Moncalvo (2002). Inonotus s. l. in Argentina--morphology, cultural characters and molecular analyses. Mycological Progress 1: 229-313.
Grand, L. F. & Vernia, C. S. (2004). Biogeography and hosts of poroid wood decay fungi in North Carolina: species of Phellinus and Schizopora. Mycotaxon 89: 181-184.
Hibbett, D. S. & Donoghue, M. J. (1994). Progress toward a phylogenetic classification of the Polyporaceae through parsimony analysis of mitochondrial ribosomal DNA sequences. Canadian Journal of Botany 73: S853
Hong, S. G. & H. S. Jung (2004) Phylogenetic analysis of Ganoderma based on nearly complete mitochondrial small-subunit ribosomal DNA sequences. Mycologia 96: 742-755.
Ko, K. S., S. G. Hong & H. S. Jung (1997). Phylogenetic analysis of Trichaptum based on nuclear 18S, 5.8S and ITS ribosomal DNA sequences. Mycologia 89: 727-734.
Ko, K. S., H. S. Jung & L. Ryvarden (2001). Phylogenetic relationships of Hapalopilus and related genera inferred from mitochondrial small subunit ribosomal DNA sequences. Mycologia 93: 270-276.
Krueger, D. (2002). Monographic studies in the genus Polyporus (Basidiomycotina). Ph. D. thesis, The University of Tennessee. Knoxville, TN. 165 pp.
Larsen, M. J. & F. F. Lombard (1988). The status of Meripilus giganteus (Aphyllophorales, Polyporaceae) in North America. Mycologia 80: 612-621.
Larsen, M. J. & X. Melo (1996). Neotypification of Phellinus pini. Mycologia 88: 839-843.
Larsson, K. H., E. Parmasto, M. Fischer, E. Langer, K. K. Nakasone & S. A. Redhead (2006). Hymenochaetales: a molecular phylogeny for the hymenochaetoid clade. Mycologia 98: 926-936.
Miller, S. L., E. Larsson, K. H. Larsson, A. Verbeken & J. Nuytinck (2006). Perspectives in the new Russulales. Mycologia 98: 960-970.
Moncalvo, J. M., H. H. Wang & R. S. Hseu (1995). Phylogenetic relationships in Ganoderma inferred from the internal transcribed spacers and 25S ribosomal DNA sequences. Mycologia 87: 223-238.
Murrill, W. A. (1905). The Polyporaceae of North America--XII. A synopsis of the white and bright-colored pileate species. Bulletin of the Torrey Botanical Club 32: 469-493.
Overholts, L. O. (1953). The Polyporaceae of the United States, Alaska and Canada. Ann Arbor: University of Michigan Press. 466 pp.
Rizzo, D. M. et al. (2003). Phellinus coronadensis: a new species from southern Arizona, USA. Mycologia 95: 74-79.
Shen, Q. et al. (2002). Molecular phylogenetic analysis of Grifola frondosa (maitake) reveals a species partition separating eastern North America and Asian isolates. Mycologia 94: 472-482.
Smith, A. H., Smith, H. V. & Weber, N. S. (1981). How to know the non-gilled mushrooms. Dubuque, Iowa: Wm. C. Brown. 324 pp.
Smith, E. C. (1930). Trametes hispida a destructive parasite in apple orchards. Mycologia 22: 221-222.
Stalpers, J. A. (1992). Albatrellus and the Heriaceae. Persoonia 14: 537-541.
Tedersoo, L., T. Suvi, K. Beaver & I. Saar (2007). Ectomycorrhizas of Coltricia and Coltriciella (Hymenochaetales, Basidiomycota) on Caesalpiniaceae, Dipterocarpaceae and Myrtaceae in Seychelles. Mycological Progress 6: 101-107.
Volk, T. J. (2000). Polypore primer: An introduction to the characters used to identify poroid wood decay fungi. McIlvainea 14: 74-82. (This article can be found online at Tom Volk's Fungi.)
Wagner, T. & Fischer, M. (2002). Proceedings towards a natural classification of the worldwide taxa Phellinus s. l. and Inonotus s. l., and phylogenetic relationships of allied genera. Mycologia 94: 998-1016.
Cite this page as:
Kuo, M. (2004, November). Polyporales: The polypores. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/polyporales.html