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

Two-in-One: Diatrypella betulina and Merismodes confusa/fasciculata

This was a stumper. I'd picked up a couple of white birch branches from the snow because something was obviously growing on them. I recognized the black bumpy eruptions as some kind of a pyrenomycete, or flask fungus, but many of those hard bumpy growths were either partially or fully covered with mysterious, minute, furry brown pellets. Insect eggs? A fungal parasite? I had no idea what they were.

Birch branches with a cup fungus growing on a pyrenomycete.

I took the branches home and stuck one in water to see what would happen. While it was soaking I looked at a sample of the pyrenomycete under the microscope and found numerous wiener-shaped spores clustered together in its asci. This made it a Diatrypella. 

Diatrypella asci produce numerous ascospores.

There aren't a lot of Diatrypella—only 33 named species worldwide. Mine had a green layer inside, which, along with its spore dimensions and birch host made it Diatrypella betulina. One down.

Diatrypella betulina has a green-tinted layer above the perithecia.

I went back to the sample I'd been soaking. The tiny brown knobs had opened into tiny, shallow brown cups, creamy smooth on the inside, and hairy on the outside. 

Water made the hairy knobs open into shallow cups.

Most cup fungi are ascomycetes and, like the Diatrypella, produce their spores in asci. But when I put a thin slice of one of the cups under the microscope I didn't find asci, I found basidia instead. This made identification easier since there are way fewer cup basidiomycete possibilities to choose from than if I'd found a hairy ascomycete.

The spores were like little bratwursts, and some of the cups' outer hairs had bulbous transparent ends. Merismodes confusa (Cyphellopsis confusa), aka Merismodes fasciculata, which is known to grow on Betula, is the closest fit.

Merismodes spores

The tips of Merismodes confusa can be bulbous and transparent.

Merismodes species are known to grow on dead wood in the crowns of trees, and several species not only colonize the stroma of old pyrenomyces, but are known to be most profuse in winter. Referring specifically to Merismodes anomala, which has tubbier spores, Andrus Voitk suggests that it probably requires "dead substrate attachment to living tree tissue." Perhaps that applies to M. confusus/fasciculata as well.

Reference:

Vasilyeva, L.N. and Stephenson, S.L. (2005). Pyrenomycetes of the Great Smoky Mountains

National Park. II. Cryptovalsa  Ces. et De Not. and Diatrypella  (Ces. et De Not.) Nitschke

(Diatrypaceae ). Fungal Diversity 19: 189-200.

Fakirova, V. I.: Pyrenomycetous fungi on a birch (Betula pendula) substratum in Bulgaria. -

Bocconea 5: 839-844.1997

Electronic Atlas of Flora of British Columbia

M. B. Ellis, J.P. Ellis, Fungi without Gills (Hymenomycetes and Gasteromycetes): An identification handbook...

Springer, 1990

 Omphalina: Betula Issue, Vol. IV, No 8

Another Fluke: Sarea resinae

I wrote about the fluke of finding Lachnellula resinaria var. resinaria in my last post—fluke because they were so incredibly tiny. I found those first ones on a dead spruce. When I went back out into the snow to look for more, I discovered an even nicer cluster growing from a large resinous canker on a dead balsam fir. It was while using my loupe at home to inspect that second batch that something else caught my eye. Something just as minute as the Lachnellula, but discoid and reddish brown. Another fluke ascomycete! 

Sarea resinae are .5-1.5 mm in size.

Fungi that tiny and dry are hard to get any information from, so I plopped the chunk of resin into a bowl of water and waited. Within an hour the dried discs had swollen and had brightened from dull red-brown to orange. Since there weren't very many, I didn't want to poke at them until I'd given them a chance to come back to life, so I stuck them in a ziplock bag overnight. The next day they'd become active enough that, with the help of the microscope, it wasn't too hard to give them a name, first Biatorella resinae, from Fungi of Switzerland (Volume I), and then, after searching around on the internet, Sarea resinae, their current name. 

Fruiting bodies are tiny, stemless discs.

Ascomycetes produce asci (plural of ascus) which contain ascospores. As a group, Ascomycetes average eight ascospores per ascus. Sarea resinae have asci that contain more than eight—way more. I didn't count them, but there were obviously several hundred tiny round ascospores in each—pretty startling when you're used to seeing fewer than ten.

A Sarea resinae ascus holds numerous ascospores.

Its ascospores are small (2-3 µm) and globose.

Sarea resinae isn't rare, just rarely found, mostly because of its tiny size. Though it usually has an association with diseased coniferous trees, there's apparently no firm evidence that it's a pathogen. Its preferred habitat just happens to be the resin exudates from cankers and other wounds. Which is where you should look if you want to find them.

Reference:

Hawksworth, D.L. 1980. Sarea resinae. CMI Descriptions of Pathogenic Fungi and Bacteria. 677 (Mycobank)