A Silver Lining to a Dog Owner’s Nightmare: Microstoma protractum

Serendipity 

serənˈdipədē

Noun: the occurrence and development of events by chance in a happy or beneficial way

My good friend, (who shall remain nameless so as not to further embarrass her), joined me for a walk in a forest a fifteen minute drive away. As always, I brought along my dog Ruby, and my friend brought along her dog — Ruby’s best buddy, Fritz. My friend offered me her plasticized “dog hammock” to cover the backseat of my car, but I poo-pooed the need for such protection. It had been dry, so I didn’t expect the dogs to get into the black smelly muck that is more easily found later in the year. Really, what could happen? 

Best buddies, Fritz (left) and Ruby (right)

Though it was a gloriously warm day, here in central Ontario it was still a few weeks too early for morels and there was still the odd patch of snow lurking beneath brush piles. Normally in early spring I have no trouble finding all kinds of interesting fungal surprises that have overwintered but, since it hadn’t rained in a week, such things as jellies and crusts and delicate cups that swell when wet, had shrivelled into invisibility. It was such a beautiful day, though, that I was happy enough to simply take pleasure in the company of my friend and the gleeful antics of our dogs racing between the trees.

A few early spring finds (from top to bottom, left to right):
Encoelia fascicularis; Merismodes sp.; Stictis radiata; Arachnopeziza aurata;
Tremella mesenterica feeding on Peniophora incarnata; and Exidia recisa.

We were nearing our turnaround point when, for a moment, we lost sight of Fritz. But then we saw him. What was he doing? Oh, dear…he was rolling in something. (If the reader has never been a dog owner, or is particularly squeamish, he/she may wish to skip down to *)

“S…t,” we both said simultaneously. 

Ruby's a cougar

Now anyone who owns a dog is likely to be familiar with this vile scenario. Be it the putrid remains of a dead animal, greasy raccoon scat, or a freshly dropped cow patty, nothing makes some dogs happier than rolling in such nastiness, usually in an anatomically deliberate way, specifically focused on grinding the offensive matter all around the neck, ears, and collar. Which is all fine and good when you’re near home and have a hose ready. It is not fine and good when you need to get home in a car, particularly a car that does not have a dog hammock protecting the backseat.

Even ten feet away from Fritz we could smell it. It was, indeed, feces. A lot of feces, smeared all through the dog’s long, silky fur.

My friend, knowing that it was unlikely that I was going to let Fritz into my car in this state, first comically tried to clean him in a vernal pond using fistfuls of last year's leaves that I handed her—a valiant attempt, but completely ineffective. In fact, the wetting and smearing of the foul substance only worsened the smell.

Both dogs love mushrooming. Fritz can be a bit of a goof!

Fortuitously, there was a river not far away and, equally fortuitously, some rags and a towel we could retrieve from the car on the way, so we headed in that direction, both my friend and I trying to keep upwind of the dog as we walked. The stench was so unbelievable it was laughable. At least, I thought it was laughable; it wasn’t my dog who had to be cleaned.

When we finally got to a shallow area at the “delta” of a spring creek running into the river, which was racing high with melt water, my friend rolled up her pant legs and waded in, dragging Fritz along with her. While Fritz was being dunked and vigorously scrubbed, Ruby splashed back and forth on the muddy shore, barking like mad to express her solidarity with her friend during his worrisome ordeal.  

*A "Good" Find

My friend finally released the newly car-worthy Fritz. Trailing streams of water from his sopping coat, he bounded directly towards me and Ruby. That, of course, was the exact instant that I spotted two little red nubbins poking out of the mud between Ruby's still dancing feet. I’m not quite sure how I managed to scoop them up before they could be either crushed or buried by a dog paw, but I did. I was now, however, a little wet since Fritz, who'd not yet had a chance to shake, managed to collide with me like a wet mop.

The cups of my Microstoma protractum were small,
but they can be up to 2 cm. wide

On closer examination, there were actually three nubbins, two of which were clearly cups. I carefully rinsed the mud and sand off them in the river. Oddly, they had very tough stems that looked as if they had rooted in the mud. I had no idea what I'd found, but I immediately declared to my friend that it was a "good" find.

"...that you would never have found if Fritz hadn't rolled in that s...t!" she said, delighted to be so easily exonerated for her dog's instinctual behaviour.

See? Serendipity.

Microstoma protractum

Once I got my find home and visually keyed it out in Ascomycete Fungi of North America (Beug, Bessette, Bessette), they were easily identifiable as Microstoma protractum (sometimes called M. protracta, an unnecessary feminization of the species name since the root "stoma" is sexless). 

Rinsed and dried, my M. protractum had dense,
felted hairs the full length of its pseudorhiza.

A hair-rimmed pore eventually opens into a torn-edged cup (with dog hair).

They're fascinating little characters, both macroscopically and microscopically. Apparently, had I not been in such a hurry to pluck them from the danger of prancing dog paws, I could have followed each tough little stem, or pseudorhiza, (a rootlike subterranean elongation of a stem), to a "mother" pseudorhiza growing from a buried piece of rotting wood. This perennial "mother" can give rise to aerial stalks each year, producing more and more cups from one year to the next. It is no wonder that so many common names in other languages refer in some way to this fungus being like a tulip: dense older colonies of M. protractum look impressively like beds of tulips. 

In German, M. protractum is called Eingerissener Tulpenbecher, or "torn tulip cup."   

M. protractum is a northern latitudes/montane species from the Sarcoscyphaceae family,  occurring in Europe, Japan, Russia, and North America. It has been found only twice in Great Britain, in Scotland, first in 1890, and then exactly 20 years later in the same location and is now likely extinct. It is also rare enough in Poland to be a protected species. Its sibling, M. floccosum, is much more common, much hairier around the rim, and does not usually grow from buried wood.

The dichotomously branched paraphyses contain plentiful pigment granules.

Microscopically it's startlingly colourful due the plentiful amounts of pigment found in its dichotomously branched paraphyses, granules that turn green in Meltzer's. The spores are large, elliptic-fusoid (25-50 x 10-16µm), usually with one large oil droplet and several smaller ones. 

M. protractum spores range in size from 25-50 µm long.

The asci have squiggly "tails."

The long asci (200-275 x 20-23 µm) are particularly interesting. Not only do they have quite lovely squiggly tails, they also each have a very cool operculum (lid that opens to release the spores) that, instead of being apical, opens to the side, which makes the empty asci look like eyeless sea creatures with their mouths open.  

The asci have strangely lateral operculi (lids that open to release their spores). 

The only thing disappointing about this fabulous little asco was that — being forced to prematurely pluck them — I did not get any pictures of them in situ. Though these lovely little red cups are, indeed, often found in moist areas just after the snow melts, I have not been able to find any reference to their growing while submerged under water, which mine must have done — the mud they had erupted from had clearly been very recently under water (earlier that day? the day before?), probably for a duration of at least several weeks while the snow was melting, and the two that were mature enough to open were packed with mud. It would have been nice to have a record of them growing in this peculiar habitat.

So I went back to see if there were more that I had missed. Though there was nothing to find in the mud beside the water in the spot I'd found the first ones, tucked behind a log a few meters away and a few feet up from the water, I found another patch — not exactly a bouquet, but enough for some photos!

Update

I went back four days after I found the second batch and found another poking out of the original spot. Here's a picture:

References

Ascomycete Fungi of North America: a mushroom reference guide. By. Michael W . Beug, Alan E. Bessette, and Arleen R. Bessette. 2014. Austin: University of Texas Press

Spinner, B. The Larger Cup Fungi in Britain, Field Mycology Volume 1(4), October 2000

Microstoma protractum on Funghi in Italia 

Microstoma protractum on Mycoquebec

Not All Fungi-eating Slime Molds are Physarum polycephalum: Badhamia utricularis

Badhamia utricularis plasmodium engulfing Pleurotus populinus.

I found my first fungicolous myxomycete (a slime mold living on a fungus) two years ago in the height of the Pleurotus populinus (spring oyster) season. If I hadn’t been deep in the woods, I would probably have been able to see it from a kilometer away, it was such an unearthly bright yellow-orange. Up close, it was clearly an extensive slime mold plasmodium that was attempting to engulf two separate clusters of oyster mushrooms that were well past their frying-pan expiry date.

Badhamia utricularis plasmodium Day 1 (top) & Day 2 (bottom)

I could have left this spectacle where it was, but I’d been wanting a new pet, so I took the whole kit and caboodle home with me. I say “pet” because I’d read quite a bit about the plasmodium of a particular slime mold—Physarum polycephalum—and had been keeping my eyes peeled, hoping to find some that I could capture and tempt into solving mazes or planning efficient rail systems by baiting it with oatmeal as other people had been doing. It sounded like fun. Cheap fun.

The yellow plasmodium travelled on an off the mushrooms for several days.

First, though, I was curious about whether or not the plasmodium I’d found was actually consuming the oyster mushrooms I’d found it on, or if it was simply passing over them. I took photographs over several days and watched my myxo completely cover the Pleurotus, then move off into a corner for a few hours (perhaps to relax and digest?), then return to the quickly shrinking mushrooms and engulf them again. It repeated this pattern for four days, and during this time the mushrooms shrank and shrank and shrank. Unusually, there were no signs of the normal larvae that one finds gorging on the tender flesh of the most edible Pleurotus species, the bane of fungi-eating people everywhere, and I believe this was solely due to the active presence of the plasmodium, which had either deterred the inevitable laying of eggs by insects or had somehow made eggs that had been laid unviable.

Plasmodium Day 4 (top) and Day 5 (bottom)

An interesting thing about Physarum polycephalum, which is studied in labs around the world, is that there are very few pictures of mature sporangia—the structures that produce spores—on the internet. There are even fewer examples of a progression from plasmodium to sporangia. Despite this lack of sporangial evidence, there are many photographs of yellow plasmodium on line that look just like mine, and a great many of these are labeled as Physarum polycephalum. Some are engulfing mushrooms. Some of these mushrooms are species of Pleurotus. Furthermore, in a 1987 paper, Quentin D. Wheeler states that Pleurotus is “so often the substrate over which this slime mold grows that the plasmodium is a field identification “character” of the fungus itself (Lincoff 1981*).” Obviously, I had found my first Physarum polycephalum. Or had I?

The sporangia beginning to form.

From early on, I was a tad disturbed by the colour of my new “pet,” which seemed a little off, a little too orange-yellow compared to the yellow to greenish-yellow it was supposed to be if it was really Physarum polycephalum. 

Sporangia beginning to get their mature blueish grey colour.

And then my plasmodium crawled away from the flattened, liquefied remnants of the mushrooms it had been consuming and formed sporangia that were not at all what they were supposed to be. In fact, what they turned into was a big whack of Badhamia utricularis.

Badhamia utricularis sporangia are brownish
before drying to blue-grey.

Surprisingly, this was not an anomaly. I found another batch of mature B. utricularis in the winter that had apparently been feeding on a Trametes before it, too, had formed sporangia. And then, again, this past spring, I found new clusters of Pleurotus populinus being eaten by, once again, B. utricularis at two different sites.

B. utricularis sporangia are usually pendant, hanging
in clusters by shrivelled yellowish strands.

So I did a little more detective work and found a most entertaining 1906 article written by a past president of the British Mycological Society, Arthur Lister: “Notes on the Plasmodium of Badhamia utricularis and Brefeldia maxima.”

Arthur Lister, who kept slime moulds as pets.

Arthur Lister made his money as a wine merchant, then retired so he could devote his time and energies to the study of botany, primarily myxomycology, which allowed him time to observe and write notes about a pet B. utricularis that he “kept in constant streaming movement on various types of woody fungi for more than a year.” (Sometimes I wish I’d been a born in the 1800s. Male. To a family of means.) (Oh, yeah—with a daughter, Gulielma, who would do all the gorgeous, detailed illustrations for my book: A Monograph of the Mycetozoa (1894.))

Gulielma Lister and her amazing illustration of Trichia affinis. 

Lister found his Badhamia on a garden log where it was consuming portions of an extensive patch of Coniophora puteana. He captured some of it and kept it alive in specially constructed boxes, allowing it to feed on thin species of Daedalea, Bjerkadera adusta, Trametes versicolor, and, its particular favourite, Stereum hirsutum. It also nibbled on Armillaria mellea and Suillus grevillei, and partially consumed some Amanita rubescens. It was not thrilled, however, when offered Hypholoma fasciculare. Though it politely fed briefly on this mushroom, it did not agree with it at all and the plasmodium, which was clearly ailing, did not look itself again until it had been rejuvenated with a fresh piece of Stereum hirsutum.

I found this clutch in the winter.

During Lister’s year of experimentation with this plasmodium, numerous colonies made the change to sporangia. Others colonies, however, though being given exactly the same conditions as the ones that had matured, continued to stream and feed. Lister was unable to discover why some chose to form sporangia while others did not. And nor have I.

Weathered Badhamia utricularis

This spring’s batch of plasmodium that I brought home swarmed over the oyster mushrooms for several days until it had turned them into a pool of mushroom-shaped muck and then it just went pfft. Total dud. Though the plasmodium of B. utricularis is capable of forming dormant sclerotium that can be revived when moistened, my last plasmodium simply shriveled up and died.

Badhamia utricularis spores & capillitium

According to Lister’s notes, he never offered his plasmodium pets any sort of Pleurotus. I wish he had so I could read his observations. In just two years, I’ve found it feeding on Pleurotus populinus three separate times, so obviously the organism takes some pleasure in eating it. I believe other people have found B. utricularis on Pleurotus as well, other people who have jumped on a Physarum polycephalus bandwagon for no other reason than their having found an extensive yellow plasmodium engulfing a mushroom or other fungus on a log. But I think it’s a fool’s game to try to name a plasmodium to species without having the proof of sporangia. Pick it up, I say. Take it home. Enjoy the antics of your new “pet” until it chooses to reveal who it really is!

A massive expanse of Fuligo septica plasmodium like this could be 
mistaken for either Physarum polycephalum or Badhamia utricularis.

References & Resources:

Lister, Arthur. Notes on the Plasmodium of Badhamiautricularis and Brefeldia maxima Annals of Botany, Volume 2 1906 

Wired magazine's article about Physarum polycephalum & Tokyo rail system

Scientific American's article about Physarum polycephalum and mazes

http://www.scientificamerican.com/article/brainless-slime-molds/

Quentin D. Wheeler, A New Species of Agathidium Associated with an "Epimycetic" Slime Mold Plasmodium on Pleurotus Fungi (Coleoptera: Leiodidae-Myxomycetes: Physarales-Basidiomycetes: Tricholomataceae). The Coleopterists Bulletin Vol. 41, No. 4 (Dec., 1987), pp. 395-403

*Lincoff, G. The Audubon Society Field Guide to North American Mushrooms, 1981 – In Lincoff’s defence, he does not say exactly what Wheeler says in the Audubon Guide. What he says in the entry for Physarum polycephalum is that they can be found “on dead wood and fleshy fungi,” and, under the entry for Pleurotus ostreatus: “It is sometimes covered by the yellow early stage of a slime mold.”

This paper is “based on greenish yellow plasmodium collected on pilei of Pleurotus sapidus,” material that was cultured and proved to be P. polycephalum:

Howard, F. L., The Life History of Physarum polycephalum. American Journal of Botany Vol. 18, No. 2 (Feb., 1931), pp. 116-133