An Overview of the Genus Cortinarius (Telluride pt. 4)

Note: this post was intended to be a micro-post, but ended up being a summary of pretty much everything I know about the genus Cortinarius, so it'd quite a substantial post indeed!

One of my fellow mushroom hunters in Telluride told me they have a joke out there, that mushrooms that look like these are called "Jac" for "Just Another Cortinarius".

Though from my experience, they could also call them "Jacki" for "Just Another Cortinarius, Kick It". So many of these mushrooms we found had been kicked over, whether from frustration at finding another non-edible species, or as a lazy technique for checking the underside for identification, I'm not sure.

Cortinarius species, commonly called corts or webcaps, are the largest Genus of Agaric (gilled) mushrooms known. They are generally non-edible, some are deadly poisonous, and even the edible ones are generally considered to be poor eating.

All Cortinarius have rusty spore prints. The gills start out as white or light-colored, but as the mushroom ages,
the spores will stain them, which can aid in identification.

Corts come in a wide variety of colors and sizes, and are the main reason I personally spore-print nearly every terrestrial (ground-growing) mushroom I gather, as they resemble many edible mushrooms. Cortinarius have rusty or rusty-brown sporeprints, separating them from blewits/Lepista nuda (light creamy pink sporeprint); edible members of the Agaricus family (chocolate brown sporeprints); Russula and Lactarius species (white and light-colored sporeprints) edible Stropharia mushrooms (purple-black sporeprint), and the honey mushrooms/Armillaria, edible Lepiotas, Tricholoma species/Matsutake/Pine mushroom, and waxy caps/Hygrophoraceae (all of which have white sporeprints). The pine spikes/ Chroogomphus have dark purple-black sporeprints, but they also have dramatically decurrent gills and aren't really easy to confuse with Corts. I don't yet feel confident enough to identify and eat Amanita, but if I did, they also have white spore prints.

As for the edible Corts, I would personally only be willing to try the "gypsy" mushroom, Cortinarius caperatus. The gypsy is much more frequently eaten than others of it's genus, and it also possesses many distinctive characteristics that aid in identification. In fact, C. caperatus is so distinctly different from other Cortinarius that for over 100 years no one even knew it was in that genus. In the late 1700s they considered it an Agaricus, but put it in with the Corts in 1838, in 1874 it was reclassified as a Pholiota, and then in 1879 given it's entirely own genus, Rozites. Many older books still list it as Rozites, because it wasn't until DNA testing in the early 2000s proved that it actually is a Cortinarius. (1838 knows where it's at!)

Anyway, many other Corts are listed as edible, but here are the reasons I won't eat them:

1. As a whole, they are infrequently consumed. In the past, some mushrooms were thought to be edible, but were actually poisonous. The most famous case of this is the brown roll-rim, Paxillus involutus. This mushroom is edible once or twice, but eventually the body develops an allergy to it, and it becomes deadly poisonous. Because the mushroom was infrequently eaten no one learned of this until a fatality. To be fair, that was in the late 1700s, but still, I am nervous around species that aren't eaten frequently.



Cortinarius iodes, aka the viscid violet cort. Or is it?!? 

2. The possibility of species confusion: It's generally pretty easy to figure out if something is a Cort,  but notoriously difficult to ID at a species level. A lot of them just look like each other. So with some Corts making you sick and some being deadly. . . it just doesn't seem worth the risk.
   Even my aesthetically my favorite Cort: C. iodes, (the viscid violet cort), has a poisonous look-alike.
   C. iodeoides, which also has bright purple shades and white patches, can make you sick. Positive confirmation requires either microscopic inspection or a taste test. And just remember, even if YOU are correct in matching a mushroom to a book, there is always the chance that the original author was incorrect in his/her ID. The more difficult the fungi is to ID the greater the chance of this happening. Of course, you should always confirm positive identification with multiple reliable sources.
3. Taste test frustration: In theory, it's perfectly safe to chew on a small portion of a poisonous mushroom (not a deadly one) for a while, and then spit it out. In fact, many positive identifications require this step. The problem is that taste is relative. For example, some people aren't sensitive to bitterness, yet determining between C. iodes and C. iodeoides requires that you recognize the later as being bitter.
4. The possibility of cumulative poisons makes me nervous. Cumulative poisoning is when you ingest a poisonous substance (in this case a mushroom) that won't kill you right away, but if you keep eating it, it has serious effects. Lead poisoning in drinking water would be an example of a cumulative poison; until it reaches a certain threshold in your system, you don't know the damage it's actually doing, and you think it's perfectly safe. This reason is sort of a culmination of all the reasons above. With Cortinarius being infrequently eaten, and hard to get a positive ID on, it's very possible are ACTUALLY eating poisonous mushrooms on occasion, but not eating enough to cause an issue. They then report that specific species as edible. 

Cortinarius identification

As I mentioned above, it's pretty easy to ID a mushroom as a Cort, at least once you get home and make a spore print, or if the mushroom is old enough that it has already dropped it's spores, and turned the gills rusty. And some people seem to have no difficulty identifying even specimens with still-white gills in the field. 

I am not one of those people. 

In theory, identifying Cortinarius is very easy. They are called webcaps because there is a web-like veil under the cap in very young specimens. This webbing is called a cortina, and it protects the immature gills until they are ready to release their spores.

The picture above is the single best specimen of the cortina I have ever found in person. Most times, this is not what you are seeing in the field.

The problem is that the cortina dissolves/wipes away/tears off/etc far more often than not, loosing that critical piece of evidence. In some cases, you can find traces of the cortina either on the stem or on the edge of the cap; if you do, they will look like rusty cobwebs, as the spores will have stained the remnants of the webby veil.

Time and time again, I've had someone pick up a mushroom and say "that's a cort.", and I'm like. . ."Really? How can you tell?" and they say "Well, right there is the remnants of the cobweb-like veil."

Meanwhile, I'm thinking to myself "that just looks like dirt to me!"

If you're like me, just bring home your possible Cortinarius for a spore print. If you are one of those who can spot veil remnants everywhere and anywhere, please share any tricks you have with me here.

The dangers of similar-looking species

The foragers in the greatest danger of fatal Cortinarius poisoning are those seeing the "Laughing Gyms", aka hallucinogenic members of the Genus Gymnopilus. Many "Gyms" come frighteningly close to resembling Corts (and also the poisonous Galerina, more on that later).

Corts have a "rusty brown" spore print, and Gyms have a "orange to orange brown to rusty" sporeprint. I don't know about you, but I'm not sure I could personally tell the difference between "rusty brown" and just "rusty" or "orange brown".  To be fair, Gymnopilus are wood-growing mushrooms, and Cortinarius grow on the ground. However, I've seen plenty cases of burried wood, tree roots, or wood so well decayed it acts as soil, that I again, emphasize caution.

Gymnopilus so closely resemble Cortinarius, that for the time being, they have been placed in the same family: Cortinariaceae. Family is the step up from genus, so if Gyms remain in Cortinariaceae, they will proove to be very closely related to Corts indeed. Full disclosure: DNA tests are being done to determine if Gyms really belong in the family Cortinariaceae, but even if they don't prove to be related, they resemble each other so strongly that scientists assumed they were.

Though the purpose of this blog is NOT to identify hallucinogenic mushrooms, I cannot stress enough how careful you must be if you hunt for Gymnopilus with an intent to ingest them. In addition to resembling Corts, Gyms also can be mistaken for Pholiota (some of which can make you sick) and deadly Galerinas, which can kill you. Both Pholiota and Galerina grow on wood, making the resemblance even closer, and Galerina also have "rusty brown" spore prints.

A case of mistaken identity

The most notable case of Cortinarius poisoning came when a famous person found a bunch of Corts and prepared them for the adult members of his family. After all became deathly ill, requiring kidney dialysis and eventual transplants, they publicly claimed they had assumed the mushrooms to be ceps (aka Boletus edulis). 

Far be it from me to impugn anyone's honor, but even the most casual collector of mushrooms should know that Boletus edulis has pores on the underside, not gills.

Perhaps other people thought this was odd, as they later amended the story to say they thought the mushrooms were chanterelles, which do have pseudo-gills, but also have bright yellow-orange colors, not the deep orange-brown hue of the deadly webcap, C. rubellus.

While this case might have genuinely been a case of mistaken chanterelle/cep identity, if it were, it would imply gross negligence on the part of the forager, as really, these mushrooms don't look much like each other.  It is also certainly true that other, non-famous, foragers have poisoned themselves on Corts while attempting to find hallucinogenic Gymnopilus, and been too embarrassed to admit that it was a trippy mushroom they were looking for.

Wether you believe hallucinogenic mushrooms should be legal or not, the fact that they AREN'T means that identification information is hard to come by, and this dramatically increases the chance that you might inadvertently poison yourself while hunting for "magic" mushrooms.