Okay, go ahead, call me weird, but ever since I found Pseudombrophila porcina polka-dotting my dog's poop last spring I've been getting down on my hands and knees in the woods to closely inspect the dung of other animals. If I see something that could be something, I bring it close to my eye so I can magnify it with my loupe.
Handling dung isn't really a stretch for me. I'm an organic gardener, so I've been intimately familiar with livestock manure for going on thirty years. Black gold, we call it. We top-dress perennials with it in the fall, dig it into the vegetable garden in the spring, and brew hundred-gallon vats of manure tea throughout the summer to use for watering.
|A small cluster of Cheilymenia stercorea apothecia on a moose pellet...|
|...and on deer dung.|
Since there's a healthy population of deer where we live, there are also plenty of piles of deer droppings in my foray woods, so these have been my primary sources for finding all kinds of mini coprophilous ascomycetes. I also stray a couple of hours further north a few times each season into moose habitat, and it was on one of these forays that I found my first Cheilymenia stercorea that were large enough (2 mm diam.!) to spot without the assistance of magnification. Since then I've found three more fruitings of these eyelash-rimmed orange disks on local deer droppings. Apparently they also commonly colonize horse and cow manure, though I haven't yet found any on my garden supply.
|An illustration of Cheilymenia stercorea (Fig. II) from 1790, back when its name was Peziza ciliata. (Bulliard)|
My favourite thing about these little guys is what their hairs look like under the microscope. Compared to their cylindrical asci, which, at about 200 µ, aren't exactly short (at least for asci), their hairs are gigantic—and spectacularly graphic. Some are multi-septate, others have barely any divisions at all, while a third type found lower on the apothecia are diagnostically stellate with two to five septate arms projecting from swollen basal cells.
|Cheilymenia stercorea hairs and asci|
|Cheilymenia stercorea hairs dwarf the asci.|
|Two three-pronged stellate hairs|
|A four-armed stellate hair|
Cheilymenia stercorea is considered to be an obligate dung decomposer—it never shows up anywhere else. There are several other outwardly similar Cheilymenia speciesthat also grow on dung, such as C. fimicola and C. raripila, but these lack the basal stellate hairs.
The spores of all Cheilymenia have an outer layer that loosens into a floating sheath around the spore "when heated in lactic acid." I haven't tried this treatment yet, as I'm not sure how one would go about doing it. It sounds so wonderfully arcane that I would like to try it. Could I just do a mount with a drop of my fermented dill pickle brine and hold a match underneath? Would that work? Perhaps someone with more experience could give me some tips.
|Cheilymenia stercorea has smooth, ellipsoid spores, slightly|
clavate paraphyses and long, slender, cylindrical asci.
References & Resources:Denison, William C., The Genus Cheilymenia in North America, Mycologia, Vol. 56, No. 5 (Sep. - Oct., 1964), pp. 718-737
Ascomycete Fungi of North America: A Mushroom Reference Guide, Michael Beug, Alan E. Bessette, Arleen R. Bessette, University of Texas Press, 2014