Mushroom Names Are Not Always What They Seem

© Else Vellinga, Ph.D.
Original publication: Mycena News, May 2012

A few years ago, we held five mycoblitzes at Point Reyes—big public mushroom events in which everybody could participate by choosing a particular part of the park and collecting mushrooms. A total of 500 different species were found during those forays, and all specimens were photographed, dried and kept in the University and Jepson Herbarium. The estimated number of species for the park lies around 900, so we still have to go out and find almost as many taxa as during those early surveys. The top 10 of most often collected species reads as follows: Armillaria mellea group, Pluteus cervinus, Helvella lacunosa, Hypholoma fasciculare, Laccaria amethysteo-occidentalis, Inocybe sororia, Sarcoscypha coccinea, Inocybe geophylla var. lilacina, Russula amoenolens, and Suillus pungens.

An undescribed Pluteus species from Point Reyes, which we used to call Pluteus cervinus. Photograph courtesy of the author.

We produced sequence data (the sequence of the four different bases in one particular part of the DNA) for some of the more common species and compared those data with data from other parts of the country and the world. We realized soon that many of the names we give to the California species are not correct. For the species that are only found in the western part of North America, such as Laccaria amethysteo-occidentalis and Suillus pungens from our top ten list, the names are right because the types were based on local specimens. Other species names were absolutely wrong even though there was a correct name available, Russula cerolens instead of Russula amoenolens is an example. The name Russula amoenolens goes with a species described from France, with a distinct smell of camembert. Russula cerolens is its west coast relative, based on collections from Oregon; these species belong to a messy group of brown Russulas with a ribbed cap. In other cases, we have no better names to use so we applied European based names. For example, Pluteus cervinus turned out to be a complex of three different, but nameless, species; the purplish Inocybe that can fruit so abundantly under the Douglas firs will get named and described as new; Helvella lacunosa is another European name, incorrectly used elsewhere, and we are in the process of naming our local western species. The jury is still out for the sulfur tuft, as we don’t have enough sequence data for it, nor for the Sarcoscypha (that beautiful red chalice); we probably use the name Inocybe sororia correctly, but we do not have a good idea about the western honey mushrooms, except that it is not A. mellea. In other words, of those ten common species, we now know with certainty that we named five of them incorrectly.

We would not have realized this unless we had carefully compared the sequence data we got with those from elsewhere: Neither descriptions nor photos would have been sufficient to decide this.

We learned from this that only by having a specimen in hand, with photos for the mushroom and its microscopic details, with data on location, habitat and fruiting date, plus a sequence, could we apply the correct name with a relatively high certainty.

We also learned that if we want to communicate about mushrooms with people from other parts of the country and the world, we have to be sure that we are talking about the same species.

The national organization NAMA has always made species lists for their forays, and since 1998 also kept voucher collections. From these lists, we find that Pluteus cervinus is found with Laccaria laccata at every place in the country the foray was held.

But, as we have seen, Pluteus cervinus from California is not one species, and as there are quite a few more hiding behind that name from other parts of the country, the name on the list is a label for at least five species. For Laccaria laccata we can tell the same story—a group of species that look all very similar, but differ subtly, but surely. In other words, currently a name on a list does not mean much.

A herbarium collection makes it possible to check the morphological characters of the species. With sequence data and information on the morphology we might to be able to use correct names for our mushrooms, or decide that names are needed, and describe the species as new.

Specimen collections, photos, information on habitat and fruiting, are all absolutely necessary as building blocks to a bigger goal: compiling from these data an online interactive key for all North American mushroom species.

We have started this project slowly, and locally, by collecting in Point Reyes, having surveys in Yosemite National Park, organizing forays in the Mendocino area, and keeping our eyes open wherever we are, but that alone will not bring such a project to fruition. We need you! To collect, document and voucher mushrooms in the first place.

These ideas about a mycoflora for North America have been circling around the Mycological Society of America for a while, and this year at the annual meeting we will hold a separate workshop to further flesh these ideas out, come up with suggestions how to organize these efforts, and who to mobilize, and especially what kind of funding sources for this project we could tap into. Of course there are bottlenecks, but we feel strongly that the project is very much needed. Thanks to modern tools and techniques and a strong support from citizen scientists (you!), now is the time that this North American Mycoflora is within reach.

Background information

Else Vellinga, Ph.D., is interested in mushroom taxonomy and has been studying mushrooms in California and beyond for years. A frequent contributor to Mycena News, she is also fascinated by interactions between fungi and other organisms. In her free time she knits, and knits, and knits!