This month's fungus is one of the sulfur shelves or chicken of the woods. It's called the "chicken of the woods" because of its remarkable resemblance to chicken meat when cooked properly. It even has the same texture and the same "peeling" that you have with chicken. Now you have probably heard that every sort of exotic meat, like emu or rattlesnake or possum "tastes like chicken," but this is certainly one of the few fungi that can make that claim. It certainly makes a very good vegetarian substitute for chicken. It's one of my favorites to eat-- but only you pick the right part of the mushroom and only if it's properly cooked. While I was in graduate school I once brought home a large specimen of Laetiporus (lay-tee-PORE-us) and cooked some for my roommates. They enjoyed it very much in a stir fry for dinner that night. There was some of the raw mushroom left over so I kept it in the refrigerator. My roommates (are you out there, guys?) decided to eat some of my food without asking, but they neglected to cook it! They got very severe upset stomachs. Oh well-- live and learn. I didn't really feel so bad about it... The chicken of the woods is one of Clyde Christensen's "Foolproof Four," first published in 1943. The others are morels, giant puffballs and Shaggy mane (Coprinus comatus). My lecture at NAMA this year is "Clyde Christensen's Foolproof Four Revisited." Laetiporus cincinnatus (Morgan) Burdsall, Banik, & Volk has recently been recognized as a separate species from Laetiporus sulphureus (Fr.) Murr. (We accomplished this in a paper with this citation: Banik, Mark T., Harold H. Burdsall, Jr. and Thomas J. Volk. 1998. Identification of groups within Laetiporus sulphureus in the United States based on RFLP analysis of the nuclear ribosomal DNA. Folia Cryptogamica Estonia 33: 9-14). It has also been called Laetiporus sulphureus var. semialbinus (although that nomenclatural combination was never "legally" made). Laetiporus cincinnatus is the correct name in Laetiporus because "cincinnatus" is the earliest available epithet at the genus level, having been described by Morgan (a high school teacher near Cincinnati) in 1885 as Polyporus cincinnatus. Peck's description of Polyporus sulphureus var. semialbinus did not come until 1905. Thus, according to priority, Laetiporus cincinnatus is the correct combination. Isn't fungal nomenclature fun? Laetiporus species have been separated from Polyporus because they cause a brown rot and have a dimitic-binding hyphal system (with clampless generative and binding hyphae) in their fruiting bodies. I recently wrote a paper called "Polypore Primer: An introduction to the characters used to identify poroid wood decay fungi." It was published in 2000 in McIlvainea 14 (2): 74-82. As promised, that paper is now online! The purpose of this paper is to explain why the old genus Polyporus has been split up into more than 100 genera and the kinds of characters that are used to distinguish the genera. In any case, others had already noticed that there was considerable variation within Laetiporus. We suspected that there were several "cryptic" species, species that are hidden within our concept of a broadly defined species. This is also sometimes called a species complex. We had been looking at the wide variation of Laetiporus specimens for many years before formal work was undertaken in 1997 by Mark Banik and Hal Burdsall of the Center for Forest Mycology Research at the Forest Products Lab in Madison, WI (where I used to work). In the species commonly called Laetiporus sulphureus, we had seen various pore colors (yellow, white, salmon) and various positions on the tree (on the stem --the "butt" of the tree-- or on the roots). They also seemed to be consistently different depending on the host (hardwood or conifer) and geography (east, west or south). Some of these had been given variety names (e.g. Laetiporus sulphureus var. semialbinus Peck) but most had been ignored as simply part of the variation to be found within species. Mark and Hal began doing the DNA studies to determine if the groups we were seeing were actually distinct enough to be called different species. Using DNA studies (involving PCR and RFLP), they found that there were at least five, maybe six groups that could be considered different species, and this aligned very well with the morphological, ecological and geographical data. They confirmed the DNA work (involving PCR and RFLP) with mating studies, in which they placed two single-spore isolates on a petri dish and allowed them to interact. With practice they could determine whether mating had taken place-- matings can only take place if they are the same species. They later confirmed the matings with further DNA studies. The first species to be split out from Laetiporus sulphureus was Laetiporus cincinnatus. It's *very* easy to distinguish between these two species. L. sulphureus L. cincinnatus L. conifericola L. gilbertsonii var. gilbertsonii L. gilbertsonii var. pallidus L. huroniensis Pore color Yellow White yellow yellow salmon yellow Position on the tree Butt of standing tree, or on down logs From soil, apparently from roots, occasionally on the butt of a standing tree Butt of standing tree, or on down logs Butt of standing tree, or on down logs Butt of standing tree, or on down logs Butt of standing tree, or on down logs Growth form Usually overlapping shelves, occasionally a rosette when fruiting from the topside of a log Usually a rosette Usually overlapping shelves, occasionally a rosette when fruiting from the topside of a log Usually overlapping shelves, occasionally a rosette when fruiting from the topside of a log Usually overlapping shelves, occasionally a rosette when fruiting from the topside of a log Usually overlapping shelves, occasionally a rosette when fruiting from the topside of a log Geographical distribution East of the Great Plains East of the Great Plains west of the Great Plains West coast known from the Gulf Coast East of the Great Plains Host tree Hardwoods, usually oak Hardwoods, almost always oak Conifers Eucalyptus Live oak, possibly other hardwoods Hemlock. possibly other conifers Other species differ in their pore color (yellow, white, or salmon), position on the tree (all the others cause a butt rot or grow on downed logs), their geographical distribution (others are more geographically restricted, such as northeast, northwest, gulf coast or southwest), and host tree (some are restricted to conifers, eucalyptus, or live oak). As it turns out most of the species are relatively easy to identify by these characteristics. So why do we care if there are more than one species of Laetiporus? This is not just one of those academic arguments that doesn't make much difference to the average mushroom hunter. The species actually differ in their taste and texture and in the percentage of each mushroom that you can eat. The only part of Laetiporus sulphureus that is usually edible is the growing edge of the fruiting body, Older parts of the fruiting body can sometimes be made palatable by boiling them in chicken soup for a couple hours. However, with L. cincinnatus the whole fruiting body is usually edible and, I think, more delicious. I've made soup, stir fry, and stew with both species. YUM! If you're only interested in Laetiporus as a forest or urban tree pathogen, it's also important to know whether the roots or the butt of the tree are affected. Both species cause a brown rot, and both are common reasons that trees fall over or break in the wind. I hope you enjoyed learning something about the chicken of the woods today. this gives you some idea of the kinds of things mycologists do to identify what a species is when we suspect that there are cryptic species buried among our species concepts. I hope you can find some Laetiporus specimens to try your own vegetarian chicken dishes -- but be sure to cook it well! If you have anything to add, or if you have corrections or comments, please write to me at volk.thom@uwlax.edu This page and other pages are © Copyright 2001 by Thomas J. Volk, University of Wisconsin-La Crosse. Return to Tom Volk's Fungi Home Page -- http://TomVolkFungi.net
The chicken of the woods is one of Clyde Christensen's "Foolproof Four," first published in 1943. The others are morels, giant puffballs and Shaggy mane (Coprinus comatus). My lecture at NAMA this year is "Clyde Christensen's Foolproof Four Revisited."
Laetiporus cincinnatus (Morgan) Burdsall, Banik, & Volk has recently been recognized as a separate species from Laetiporus sulphureus (Fr.) Murr. (We accomplished this in a paper with this citation: Banik, Mark T., Harold H. Burdsall, Jr. and Thomas J. Volk. 1998. Identification of groups within Laetiporus sulphureus in the United States based on RFLP analysis of the nuclear ribosomal DNA. Folia Cryptogamica Estonia 33: 9-14). It has also been called Laetiporus sulphureus var. semialbinus (although that nomenclatural combination was never "legally" made). Laetiporus cincinnatus is the correct name in Laetiporus because "cincinnatus" is the earliest available epithet at the genus level, having been described by Morgan (a high school teacher near Cincinnati) in 1885 as Polyporus cincinnatus. Peck's description of Polyporus sulphureus var. semialbinus did not come until 1905. Thus, according to priority, Laetiporus cincinnatus is the correct combination. Isn't fungal nomenclature fun?
Laetiporus species have been separated from Polyporus because they cause a brown rot and have a dimitic-binding hyphal system (with clampless generative and binding hyphae) in their fruiting bodies. I recently wrote a paper called "Polypore Primer: An introduction to the characters used to identify poroid wood decay fungi." It was published in 2000 in McIlvainea 14 (2): 74-82. As promised, that paper is now online! The purpose of this paper is to explain why the old genus Polyporus has been split up into more than 100 genera and the kinds of characters that are used to distinguish the genera.
In any case, others had already noticed that there was considerable variation within Laetiporus. We suspected that there were several "cryptic" species, species that are hidden within our concept of a broadly defined species. This is also sometimes called a species complex. We had been looking at the wide variation of Laetiporus specimens for many years before formal work was undertaken in 1997 by Mark Banik and Hal Burdsall of the Center for Forest Mycology Research at the Forest Products Lab in Madison, WI (where I used to work). In the species commonly called Laetiporus sulphureus, we had seen various pore colors (yellow, white, salmon) and various positions on the tree (on the stem --the "butt" of the tree-- or on the roots). They also seemed to be consistently different depending on the host (hardwood or conifer) and geography (east, west or south). Some of these had been given variety names (e.g. Laetiporus sulphureus var. semialbinus Peck) but most had been ignored as simply part of the variation to be found within species.
Mark and Hal began doing the DNA studies to determine if the groups we were seeing were actually distinct enough to be called different species. Using DNA studies (involving PCR and RFLP), they found that there were at least five, maybe six groups that could be considered different species, and this aligned very well with the morphological, ecological and geographical data. They confirmed the DNA work (involving PCR and RFLP) with mating studies, in which they placed two single-spore isolates on a petri dish and allowed them to interact. With practice they could determine whether mating had taken place-- matings can only take place if they are the same species. They later confirmed the matings with further DNA studies.
The first species to be split out from Laetiporus sulphureus was Laetiporus cincinnatus. It's *very* easy to distinguish between these two species.
L. sulphureus
Pore color
Yellow
Position on the tree
Butt of standing tree, or on down logs
Growth form
Usually overlapping shelves, occasionally a rosette when fruiting from the topside of a log
Geographical distribution
East of the Great Plains
Host tree
Hardwoods, usually oak
Other species differ in their pore color (yellow, white, or salmon), position on the tree (all the others cause a butt rot or grow on downed logs), their geographical distribution (others are more geographically restricted, such as northeast, northwest, gulf coast or southwest), and host tree (some are restricted to conifers, eucalyptus, or live oak). As it turns out most of the species are relatively easy to identify by these characteristics.
So why do we care if there are more than one species of Laetiporus? This is not just one of those academic arguments that doesn't make much difference to the average mushroom hunter. The species actually differ in their taste and texture and in the percentage of each mushroom that you can eat. The only part of Laetiporus sulphureus that is usually edible is the growing edge of the fruiting body, Older parts of the fruiting body can sometimes be made palatable by boiling them in chicken soup for a couple hours. However, with L. cincinnatus the whole fruiting body is usually edible and, I think, more delicious. I've made soup, stir fry, and stew with both species. YUM!
If you're only interested in Laetiporus as a forest or urban tree pathogen, it's also important to know whether the roots or the butt of the tree are affected. Both species cause a brown rot, and both are common reasons that trees fall over or break in the wind.
I hope you enjoyed learning something about the chicken of the woods today. this gives you some idea of the kinds of things mycologists do to identify what a species is when we suspect that there are cryptic species buried among our species concepts. I hope you can find some Laetiporus specimens to try your own vegetarian chicken dishes -- but be sure to cook it well!
