Gyromitra esculenta and Gyromitra gigas: Two False Morels

Gyromitra esculenta contains large amounts of the toxin, gyromitrin.

When we first moved to east-central Ontario, old timers on our road told us they'd seen people coming out of our woods every spring with garbage bags filled with morels. Green garbage bags! So every spring we've battled black flies and mosquitoes, and poison ivy so fresh you just have to look at it to get a half-body rash, in search of this mythical motherlode, and every year we've fallen short. A few morels, yes. Garbage-bagsful, absolutely not.

What was going on? Where were these famous mushrooms? I finally figured it out when, one May day, I bumped into a stranger in the woods. A stranger with a big bag full of...not delectably edible morels, but false morels—Gyromitra esculenta, to be precise. He'd been eating them for years, he told me. 

"Maybe not for many more," I suggested, a less confrontational reply, I decided, than starting a discourse about trespassing.

Unlike real morels, false morels, like Gyromitra esculenta, are not hollow.

Though we could, indeed, easily fill garbage bags with the crop of G. esculenta that pops up in our local woods every spring, we won't be eating any of them, because they, and several other Gyromitra species, contain varying amounts of gyromitrin, a toxin and probable human carcinogen that metabolizes in the body into—believe it or not—rocket fuel (monomethylhydrazine). 

Though people claim that by using specific cooking methods they can render various Gyromitra species edible ("esculenta" actually means "edible"), there may be long-term cumulative effects of the toxin, and 2 to 4 percent of all fungal fatalities are associated with them. Before anyone convinces you to try eating one, please read Tom Volk's excellent page on their toxicity.  

Though there's a fall species in my area, G. infula—that's usually saddle-shaped and grows on rotting logs—the only spring one I've found around here is G. esculenta. Last weekend, though, on a Mycological Society of Toronto foray northeast of the city, we found a different one.

Gyromitra gigas looks less "brainy" than G. esculenta.

I have no photographs of it in place because, before I plucked one for display, it fooled me into thinking it was G. esculenta. Its fertile surface was a warm brown, and it was somewhat contorted. I didn't look at it closely until I got back to the parking lot and saw that it was less "brainy" looking than usual, had an abnormally stout stipe, and, when I cut it in half, had cottony white material in its convoluted interior. It wasn't  an abnormal G. esculenta, it was G. gigas, (often split into G. korfii in the east, and G. montana in the west).

Gyromitra gigas has a convoluted interior.

Cottony interior of Gyromitra gigas

Gyromitra esculenta and G. gigas differ even more different under the microscope. The spores of G. esculenta are kind of nice in their smooth, fusiform to elliptic clarity, usually containing two oil droplets at either end, while those of G. gigas are slightly roughened and fusiform, with several small oil droplets orbiting a larger central one. Most notably, though, the spores of G. gigas have two knob-like apiculi at either end.

Gyromitra esculenta spores have two oil droplets.

Gyromitra gigas asci, spores, and colored paraphyses.

Gyromitra gigas spores have knoblike apiculi on either end.

Gyromitra gigas apparently contains much less gyromitrin than G. esculenta, and is thus generally considered to be a safe edible, but since this G. gigas appears to be a species complex that may vary considerably from place to place I think I'll wait until more study is done before eating it.  



References:

Gyromitra gigas on Mycoquebec
Gyromitra esculenta on Tom Volk's Mushroom of the Month




Tom Volk's excellent page about Gyromitra toxicity.

Chlorociboria and Patinellaria sanguinea: Colourful Wood Spalting Fungi

Patinellaria sanguinea stains wood coral red. 

It’s easy to forget while collecting fungi that the ones we find growing on wood and elsewhere are only their fruiting bodies—the actual organism is usually hidden, its mycelium buried deep in wood or soil. But the microscopic mycelium of some wood-loving fungi make it very clear just how large an area they’ve taken over by staining the wood they’ve colonized. This staining, which can sometimes be dark lines, other times extensive areas of colour, is called spalting.

Wood stained blue-green by the fungus Chlorociboria.

The fairly common Chlorociboria aeruginascens and its sister C. aeruginosa, which can only be differentiated microscopically, stain the wood they’ve colonized a stunning blue-green with the pigment xylindein. This beautiful blue wood has been used by woodworkers since at least the 15^th century, primarily in inlays (see examples here). It’s such a striking colour that studies are underway to find a way to inoculate various forest trees with Chlorociboria to enhance the value of the lumber. Personally, I’m impressed that anyone has ever found a piece of this blue wood in good enough shape to use for anything other than as a conversation piece. In my experience, whenever I find it, the wood is already so decomposed I can easily pull it apart with my fingers.

Chlorociboria produces gorgeous blue-green fruit bodies.

Serendipitously, I recently came across a much more uncommon Helotiales that also stains wood.

Slightly dried Patinellaria sanguinea discs and subiculum.

A month or so ago, I brought in a branch I’d left outside for the winter that had had the beginnings of a mystery purple crust growing on it in the fall. I hoped that by giving it a little warmth and moisture it might revive and offer me some spores to help in its identification. But nothing happened. Well, actually something happened—the purple corticioid started decaying. I was about to relegate the branch to the kindling pile when I noticed that in a couple of places its surface was oddly coloured with reddish-pink spiderwebby fuzz. I assumed this was just an unusual mold, but when I got out my loupe to inspect it I was surprised to see a multitude of minute blackish discs embedded in it. Helotiales type discs. Hmm.

Amazing colour of "black" Patinellaria sanguinea fruit bodies under the microscope.

When I put a sample under the microscope I immediately saw that the pink fuzz was not a mold, but a hyphal mat, or subiculum, that clearly belonged to the blackish discs. Not only that, but, when sectioned, the “black” discs were actually quite strikingly coloured. There were even some asci and spores.

Wonky ellipsoid to clavate spores of Patinellaria.

I didn’t have a clue what it was, or even how to start looking to find a name since nothing like it was in either Fungi of Switzerland or the brand new Ascomycete Fungi of North America. I got my knife out and carved a few chunks off the branch to dry for later study. It was only then that I realized my little ascomycete had another interesting characteristic: it had stained the wood a gorgeous coral red. Surely, I thought, this would make finding its identity easier. But still no luck on Google or Ascofrance or anywhere else.

Days passed. I was doing an unrelated image search for another minute black disc, Patellaria atrata, this one sans color, when halfway down the page a picture jumped out at me. It clearly showed exactly what I had accidentally grown—mini blackish discs with a pinkish red subiculum. And they had a name. Panitellaria sanguinea.

I have not been able to find out much about this little curiosity, which has also been known as Durella sanguinea and Peziza sanguinea, other than that it’s rare, grows in North America and Europe, and apparently prefers hardwoods. If anyone can add anything else, I’d be grateful.

More Info:

Tom Volk’s Chlorociboria page

Panitellaria sanguinea on Mycoquebec

Panitellaria sanguinea on Mycokey
Robinson, S.C., Tudor, D., Snider, H., Cooper, P.A. 2012. Stimulating growth and xylindein production of Chlorociboria aeruginascens in agar-based systems. AMB Express 2(15).
More about spalting: Northern Spalting

George Grant Hedgcock. "Studies Upon Some Chromogenic Fungi which Discolor Wood." St. Louis, 1906

A Poop & Scoop Ascomycete: Pseudombrophila porcina

Our puppy Ruby—now almost a year old—developed an interesting habit after the first snow last fall: she used her snout as a shovel to meticulously bury every one of her droppings. Okay with us. Out of sight, out of mind, as far as we were concerned. But when the big thaw happened a couple of weeks ago we ended up with a major yard and garden clean-up that had nothing to do with last year's plant matter. 

As happens, we missed a couple, and a few days ago I came across one of these strays. I was about to scoop it up with a shovel and toss it into the woods when I noticed something peculiar about it. It was polka-dotted. 

Sigh. 

I knew what I had to do—get out my loupe so I could closely inspect, yes, my dog's doodoo. This is the life of an ascomycetes freak. And here's what I saw, which, precisely because I've turned into an ascomycetes freak, was exciting:

Immature Pseudombrophila porcina on dog feces.

I'd obviously found a coprophilic fungus. A dung lover. But which one? There are lots to choose from, especially from the ascomycetes clan. "Lots" is a good thing—I don't know about everybody else but I like the idea of animal dung being broken down and returned to the earth as quickly as possible, and fungi are perfect for the job.

Immature Pseudombrophila look like tiny beads.

My find was clearly immature, so I got a couple of pieces of toilet paper and a pair of tweezers and brought a sample into the warm house where I dampened the paper. With this simple coaxing, two days later the tiny brown beads had turned into pale beige discs with furry exteriors. The biggest was about 2 mm across.

Mature Pseudombrophila porcina are still tiny.

A bit of digging got me to two very similar species in the genus Pseudombrophila that are both known to colonize herbivore and carnivore dung, P. porcina and P. merdaria. After reading an illuminating discussion about these two on Mycofrance, I went to the microscope. 

Pseudombrophila porcina spores.

The spores were smooth and the tips of the paraphyses were not inflated, so it looks like mine are Pseudombrophila porcina. 

I hate to say it, but as unpleasant as animal dung might be, for people like me it's still worth taking a closer look. 

References:

Pseudombrophila porcina on Mycoquebec
Pseudombrophila merdaria on Mycoquebec 
Ascomycete Fungi of North America: A Mushroom Reference Guide, Michael Beug, Alan E. Bessette, Arleen R. Bessette, University of Texas Press, 2014

A Novel Way to Reproduce: Pleonectria strobi

Pleonectria strobi

Surprise! Something really small! I can't help it—it's still too early here for morels or any other macrofungi so I've been wandering through the snowless, leafless woods looking for out-of-place dots. White dots on branches could be Lachnellula, yellowy orange dots on rotting logs could be one of the smaller Dacrymyces, vivid blue-green ones could be just-starting Chlorociboria. You never know what you're going to find when you're looking for dots, and two days ago I found some some very interesting ones.

Pleonectria strobi can be up to 1 mm., but are usually smaller. 

They were minute and orange, growing in clusters along the length of a twig. I thought at first they were tiny cups, but on closer inspection saw that they were actually some kind of Nectria that had become cupulate from drying in the sun. Moistened, they became much more globose. But what kind? Nectria cinnabarina, which is relatively common, is restricted to broadleaf trees. The ones I'd found, though, had erupted from pine—specifically white pine (Pinus strobus). They also seemed smaller than Nectria cinnabarina and brighter orange, the brightness due to a yellow scurfiness on their surface.  

To get a clearer idea of what they were, I squashed a few under a slide cover and stuck then under the microscope. I immediately found multiple asci, most of which were jam-packed with very tiny, slightly curved spores, so packed that, even as I watched, they were bursting out in streams of a hundred at a time. Very exciting, but also very wrong. Nectria species are supposed to produce asci containing 8 ascospores apiece, not hundreds. So what was up?

Ascoconidia streaming out of ascus.

It turns out that what I was seeing were not ascospores but ascoconidia, and what I'd found was not a simple Nectria, but a Pleonectria.

Asci stuffed with ascoconidia.

Many ascomyctes have two different ways of reproducing: sexually and asexually. Asexually they produce conidiophores that release conidiospores, which are haploid, having only one set of chromosomes instead of two. I've seen lots of conidiospores before, but none of them had been inside asci. That's because asci, as a rule, are normally reserved for the production of ascospores. This is not, however, the case for some rule-breaking Pleonectria, including the one I had found, Pleonectria strobi. As is to be expected, each Pleonectria strobi ascus first produces 8 ascospores, but then the fun starts. Ascoconidia bud off each of the filiform, multiseptate ascospores, so many, in fact that, according to Fungi of Switzerland, Vol.1, the ascospores are completely consumed. 

The multiseptate ascospores of Pleonectria strobi
look a little wormlike and vary in length.

The ascospores were certainly extremely difficult to find under the microscope. Interestingly, the ones I eventually did find were outside the asci, so perhaps not all of them are doomed to the service of generating ascoconidia. 

Reference:

Hirooka Y, Rossman AY, Samuels GJ, Lechat C, Chaverri P. (2012) A monograph of Allantonectria, Nectria, and Pleonectria (Nectriaceae, Hypocreales, Ascomycota) and their pycndial, sporodochial, and synnematous anamorphs. Studies in Mycology 71: 1–210.

With a Little Help from Arthropods: Catinella olivacea

Fresh Catinella olivacea (photo courtesy Andreas Gminder)

By March the snow that had accumulated since November was so deep in the woods that my search for winter fungi was mostly confined to standing trees and hung logs. I found the shrivelled little black discs (below) on the underside of a dead alder suspended above the snow. 

Shrivelled Catinella olivacea in winter.

Though they looked quite degraded, I managed to perk them up enough at home with warmth and a bit of moisture to not only get a vague idea of their truer form, but to also get a spore sample. 

The slipper-shaped spores of Catinella olivacea.

The ascospores are pretty cute—they look just like those outlines of feet, both men's and women's, that they used to use in diagrams to show dance steps. These foot-shaped ascospores helped me figure out that what I'd found was Catinella olivacea (or Karschia olivacea in older books). 

My 25-cent lawn-sale Rhumba lesson record.
See? Catinella spores.

They're small disc-shaped fungi, even when fresh (2-15 mm diam.), and attractively bicoloured, with a greenish- to olive-black fertile surface rimmed with a slightly raised, paler, ochreous margin. The fertile surface is often studded with beads of moisture.

Catinella olivacea is an ascomycete that's not uncommon, just rarely found since its usual haunts are either deep inside rotting cavities or hiding on the undersides of logs. Most fungi rely on air currents to disperse their spores. Not Catinella olivacea. Tucked away and sheltered from wind, it has evolved another strategy to move its spores around. The fertile surface becomes gelatinous at maturity, trapping the forcibly ejected ascospores in sticky droplets. All this fungi needs to do is sit and wait for a passing springtail, or centipede, or woodlouse, or other arthropod to take a step or two across its surface and—bingo!—its ascospores are carried off, later to be deposited somewhere else.

Sticky, ascospore-laden droplets adhere to passing arthropods. 

Along with its special mode of spore dispersal, Catinella olivacea also has peculiar developmental characteristics that are unlike other disc-shaped Heliotales. Interestingly, rDNA studies have now shown that these little guys are more closely related to the Dothideomycetes, which include a large number of plant pathogens, than to the Leotiomycetes, the class that Heliotales belong to.


References:

Catinella olivacea on Mycoquebec

Matthew D. Greif, Connie Fe C. Gibas, Akihiko Tsuneda, Randolph S. Currah, Ascoma Development and Phylogeny of an Apothecioid Dothideomycete, Catinella Olivacea, American Journal of Botany 94(11): 1890–1899. 2007