Galerina autumnalis, aka “The Deadly Galerina” (by Douglas Smith)
This month we take a look at a little brown job, that is dear to my heart but probably not to most of yours. Galerina autumnalis is a small brown job, growing on well rotten logs and stumps during wet months. And as a small brown job, why do people care at all here, since for most people those are the mushrooms you do best to ignore? This species has been shown to contain the same toxins as that of Amanita phalloides, a.k.a. “the Death Cap”. That species has been associated with the most cases of deadly poisonings around the world. But in the case of G. autumnalis since it is a LBJ (little brown job), it is rarely the case of mushroom poisonings, since who wants to eat LBJs anyway? But it comes up positive in tests for amanita-toxins, and in lists of poisonous mushrooms it always makes the cut. And people are always fascinated with deadly things, now, aren't they?, what does this guy look like in the field? G. autumnalis grows on well rotted logs and stumps, not twigs or leaf litter, so look for big damp things. It is a small brown mushroom, 1-3 inches in size, with light tan gills, a central stipe, and the stipe has a fibrous veil that is on the upper stipe that is usually brown with spore color, and collapsed downward. The cap is usually rounded, and only slightly striate right at the margin. The stipe is usually very dark coffee brown from the base, with a light coating of very pale fibrous hyphae below the veil. It often is found gregarious in clusters on the log, but sometimes found in small numbers or singly. Following those details, you should be able to id to this species. It is found usually in the Bay Area on live oak, but north of the bay area it can be found also on the coast on usually Douglas fir, and sometimes other conifers.
But if it is small and brown, why is a concern as a poisonous mushroom? As in all cases, mushrooms are not deadly or dangerous at all, as long as you don't eat them! Well, there are some people that have been known to be indiscriminate in trying small brown jobs, and accidentally eat one of these in a mix of other small guys. Usually these people are looking for mushrooms with dark purple-brown-black spore colors, where Galerina has a medium brown spore color. But you will have to find some of these people to ask for more details — personally, I have no idea why you would want to eat small brown mushrooms.
This is a small concern for California, but in other places in the world, there are other concerns regarding confusion with mushrooms that are considered good edibles. In the east it has been reported that people have confused Galerina autumnalis with Armillaria mellea, a.k.a. “the honey mushroom”. Armillaria species also grow on stumps, and usually in tight clusters, have brown caps, and a veil on the upper stipe. But Armillaria species have white spores, and the veil is much more persistent, and usually much larger.
Many people would not confuse these mushrooms, but it has been reported that beginners excited by large fruitings of Armillaria on a stump, may grab a Galerina on the same stump without noticing. In other places in North America and more in Europe, there is also Kuehneromyces mutabilis, which is much closer to Galerina, in fact one source moved the mushroom into the genus of Galerina, but it is now recognized as its own genus by everyone today. Kuehneromyces mutabilis is a small to medium sized brown mushroom that grows on rotting logs and stumps, with a fibrous veil on the upper stipe,
which sounds the same as Galerina autumnalis, but it differs in that it has scales on the stipe below the veil, and grows in tight clusters with attached stipes usually. Kuehneromyces mutabilis, in Europe at least, is considered a good edible by some, but is not a very popular mushroom for the table. Avoidance is mostly because of concerns over confusing it with a Galerina.
But are those the only look-alikes? Of course not! As a small brown mushroom, there are quite a few others that could get confused with Galerina, such as many members of the genus Pholiota, or Gymnopilus. But perhaps closer, there is Pholiotina rugosa, and other species of Pholiotina, a cousin genus to Conocybe. Pholiotina rugosa is small brown, with brown spores and a veil on the stipe. But Pholiotina usually grows on small woody debris, and the veil is more membranous and is in the middle of the stipe, not on the upper stipe. Pholiotina rugosa doesn't really look like Galerina once you've seen a few of them, but there are other unknown species of Pholiotina out there, that look much more like Galerina. These can be easily separated under the scope, but not always by eye really.
And there are other species of Galerina: Galerina badipes is small and brown, on wood, and has a fibrous veil on the upper stipe. But this Galerina is strongly striate, and is on small woody debris, not large logs. This Galerina is in the same section as G. autumnalis, the section Naucoriopsis, and it has been shown that other species in this section also test positive for amanita toxins. All species in this section should be considered suspect.
But is Galerina autumnalis the main concern of small brown mushroom poisonings? Of course not! There are so many small brown wood rotting mushrooms, and so few of them have been tested for amanita toxins, or anything is known about their toxicity at all. Pholiotina rugosa has been reported as toxic as well, and there might be confusions in reporting as to what species may have caused the poisonings. I was part of a poisoning discussion, where a test of amanita toxins came back positive, but the actual mushroom was never saved, photographed or ID'ed, there was a poisoning and a test, that was it. The conclusion was that it was a Galerina poisoning, but I was left with more questions. Might there be more small brown mushrooms that are just as poisonous? Yes, I would think so, but do we know enough yet to say which ones, and how many? Not even close.
And there is the question: is Galerina autumnalis still a valid species? Maybe not! Years ago genetic studies were done on Galerina species in the section of Naucoriopsis, all similar to Galerina autumnalis. And this study showed that there is very little difference in the genetic sequences obtained between Galerina autumnalils, Galerina marginata, Galerina unicolor, Galerina venetata, and some others. The conclusion was that these are all actually the same species, and the oldest name is valid, which is Galerina marginata. It is true, that the only difference between G. autumnalis and G. marginata was that the cap is viscid/slimy in G. autumnalis, and not in G. marginata, and collapsing these to the same species is probably a good idea. But that is probably not the full story, and time will tell to see if there are more species in this section of Galerina.
So, look around when out there, on well rotted damp logs, for this little brown job. There is a world of mystery, and so many things are still unknown here. There is also danger, and lots of care to be taken if you are thinking about eating little brown jobs.