Calling all mycologist, ecologists, photographers, and students of the Delaware Highlands river valley:
The DHMS Polypore Identification Project is collecting photographs of Polypores from our area.
An identification session will be announced soon.
For most of 20th century polypores were treated as a family, the Polyporaceae. Reconstructions of family tree of fungi show that the poroid fruiting body has evolved numerous times in the past. Modern DNA-based evolutionary classification places polypores to at least 12 orders. The orders containing most polypore species are the Polyporales (genera such as Fomes, Polyporus and Trametes) and Hymenochaetales (e.g. Oxyporus, Phellinus and Trichaptum). Economically perhaps the most significant polypores Heterobasidion spp., pests of conifer plantations, belong to the Russulales. Other polypore orders are the Agaricales, Amylocorticiales, Auriculariales, Boletales, Cantharellales, Gloeophyllales, Sebacinales, Thelephorales and Trechisporales.
The Polyporales in the modern sense are not only polypores but also other fruiting body types such as crust fungi, hydnoid fungi and agaricoid mushrooms. The term polypore describing a morphological group should not be confused with the taxonomic groups Polyporales or Polyporaceae of the modern literature.
Currently polypores are divided into about 170 genera. That number is bound to rise significantly through better understanding of evolutionary relationships between species and through mapping of uncovered diversity in the tropics. All in all classification of polypores is in flux.
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.