Clumsiness Pays Off: Lachnellula subtilissima and Podospora appendiculata

Podospora appendiculata on rabbit dung

It was the first collecting morning of the Mycological Society of Toronto's annual Cain Foray. As usual, I didn't get very far from where we parked our cars. That's what happens when you're looking for the small stuff—for ascomycetes and slime moulds. But even when you're specifically looking for tiny things, help is sometimes needed. In this case, help was my own clumsiness—I skidded along the length of a slippery branch and went down.

This sort of thing seems to be happening to me with some frequency these days. Fortunately I haven't yet speared my liver with a broken branch or snapped a bone, though I've often enough ended up lying prone—which turns out to be a terrific position from which to spot the incredibly tiny things I'm looking for, things I'd never be able to see from a normal person's upright stance. 

Lachnellula subtilissima is a tiny species.

This time, the first thing I saw was a conifer twiglet sporting a couple of white dots. My loupe exposed a grand total of three minute egg-yolk yellow disks rimmed with white fur—a Lachnellula of some sort.  

I wasn't ready to get to my feet yet, so I poked around in the duff and found a rabbit pellet. At first I thought it was a dud since none of the tiny coloured disks or hairy cups I've come to expect on dung jumped out at me. Magnification, however, revealed several minute black oddities that I thought at first might be undigested seeds—except they were hairy, and they were all oriented pointing outwards. Weird little characters. 

Podospora appendiculata are ornamented with short bristles.

Lachnellula subtilissima

It wasn't until I got home a couple of days later that I was able to spend enough time with my finds to identify them. Once I'd given the Lachnellula a couple of days of warmth and moisture, which prompted it to produce spores, it was clear that it was L. subtilissima. 

Lachnellula subtilissima spores

Lachnellula subtilissima asci and paraphyses

Lachnellula subtilissima hairs are septet and covered with fine granules.

Podospora appendiculata

The pear-shaped coprophilous guys on the rabbit dropping were a bit more tricky to nail down, but once I'd plucked one off with tweezers and took a closer look I realized it was a flask fungus, some kind of pyromycete (now taxonomically Sordariomycetes), so that was a start. But it wasn't until I'd isolated some mature spores and found their crazy colourless tails that I was able to find the genus and species—Podospora appendiculata. Until this point, the only ascomycetes I'd found on dung had been Pezizales, or cup fungi, so it was exciting to have found something from a class that I'd only found on wood before. The length of the gelatinous appendages, or caudae, on the spores, as well as the character of the hairs, pointed to P. appendiculata, which is apparently not uncommon, just uncommonly noticed, and is frequently found on rabbit dung. 

Podospora appendiculata are barely a millimetre tall.

Podospora appendiculata spores and asci at different stages of maturity.

Podospora appendiculata have 1-2 septate hairs with hyaline
ends and spores with gelatinous appendages.

The cauda at the base of the spore is attached to a hyaline pedicel. 

References and Resources:

H.O. Baral's Worldwide Key to Lachnellula (pdf)

IMI Descriptions of Fungi and Bacteria No. 1649: Lachnellula subtilissima

Dung Fungi: an illustrated guide to coprophilous fungi in New Zealand, by Ann Bell. Victoria University Press, Wellington; pp. 88, 1983

Podospora on Ascofrance

Mycological Society of Toronto
See also my post on Lachnellula resinaria var. resinaria

Busting the “No Known Poisonous Polypores” Myth: Hapalopilus nidulans

The cap of Hapalopilus nidulans starts out finely tomentose
but becomes glabrous with age.

I don’t know how many times I’ve read this phrase over the past couple of years: “There are no known poisonous polypores.” I see it mostly on internet forums, and mostly on threads about edible or medicinal fungi. Someone will excitedly post a photo of their first “chicken of the woods” (Laetiporus sp.) or “reishi” (Ganoderma sp.), photos that regularly, and clearly, show that the poster has got the wrong ID. This happens unbelievably frequently with the fad medicinal, “chaga” (Inonotus obliquus). A photo of a burl or gall, growing on the trunk of a tree that is obviously not a Betulina of any sort, will be posted as “chaga” and everyone will chime in their congratulations and suggest that the finder immediately race back to hack away at a living tree with a hatchet to claim his or her "prize." When someone sensible suggests that one of the above IDs may be flawed, another poster will jump in with the claim that a misidentification doesn’t matter anyway since “there are no known poisonous polypores.”

Well, it’s not true. There is at least one seriously toxic polypore, Hapalopilus nidulans (H. rutilans).  

Hapalopilus nidulans can be overlooked since it's often
quite small and frequently grows alone.

H. nidulans is an unassuming, cinnamon-coloured polypore that can grow up to 10 cm wide, though it's usually considerably smaller. It has a rough or smooth cap and small angular pores, 2-4 per millimetre. When fresh, its flesh is soft and watery; when dry it's tough and hard and can be quite brittle. A white rot agent, it prefers a wide variety of deciduous trees, but can occasionally be found on conifers. Though it's widely distributed east of the Rockies, it's not particularly common. 

The small, angular pores of Hapalopilus nidulans

An Impressive Chemical Reaction

Basically, it's an easily overlooked, unexciting fungus—unless you happen to have some KOH handy, or a bottle of ammonia tucked under your kitchen sink. Personally, I loathe the smell of ammonia, probably because I once had a 19-year-old cat that could no longer find its box. Though that cat is long dead, I still put up with the stink of ammonia since this inexpensive cleaning solution is a wonderful tool for any fungiphile as many species of bolete undergo specific colour changes when hit with a drop of it—as does H. nidulans.

When this otherwise boring fungus comes into contact with either ammonia or KOH, it immediately turns a psychedelic fuchsia (or cherry red in other parts of the world), a reaction that's so magical and so spectacular it's hard not to play with the effect over and over again. At least it is for me. It's also a fabulous part of anyone's arsenal of ultra-cool things to get kids interested in mycology, along with reconstituting jelly fungi and locking children in dark closets with bioluminescent mushrooms. H. nidulans is also much sought after as a natural dyeing agent that—again with the help of ammonia—produces purples that are both more vivid and more fast than those produced by other fungi.

A drop of KOH or ammonia on Hapalopilus turns it a crazy purple/fuchsia
—though not as crazy as these web colours are making it look.

Toxicity

And apparently there's also nothing boring about eating this humble little character, though, from the sound of it, there's nothing pleasant about it either. The few cases of poisonings on record, including one adult and two children in the late Eighties, and a father and daughter a couple of years ago, (the latter incident involving the consumption of H. nidulans after misidentifying it as the "beefsteak fungus," Fistulina hepatica), have all been similar in their descriptions of signs and symptoms that happen after a delay of at least 12 hours, the results of dysregulation of central nervous system functions and liver and kidney dysfunction:

• abdominal pain
• nausea and vomiting
• headache
• visual disturbances, including double vision, blurred vision, hallucinations
• multidirectional involuntary eye movements
• balance disorders 
• general weakness
• loss of appetite
• signs of liver and kidney failure
• and violet-coloured urine

The culprit is likely polyporic acid, which can make up an astonishing 40% of H. nidulans by weight. In a lab study, rats given straight polyporic acid via probang developed "strongly reduced locomotor activity, depressed visual placing response and impaired wire manoeuvre," as well as hepatorenal failure and low blood potassium and calcium levels, symptoms that closely parallel those of the people who ate the fungus. I am not sure if the urine of these poisoned rats turned purple or not—but I bet a cat's would! 

Hapalopilus nidulans is watery and soft when fresh and often feasted
on by slugs that are, presumably, unaffected by polyporic acid.

As noted above, the father and daughter poisoned by H. nidulans mistook it for Fistulina hepatica, which is a well-known edible. I have to assume they were not experienced foragers since there are very clear differences between Hapalopilus and Fistulina. Unlike the soft, fibrous flesh of H. nidulans, the flesh of F. hepatica is strangey meat-like, streaky whitish and reddish, and "bleeds" a reddish liquid when squeezed. The surface texture of both cap and stem is finely, and peculiarly pebbly. The tubes on the undersurface are also completely different—easily separable because they are not fused together as they are in most polypores (see my Cyphelloid Wannabes post for more info). 

Two people poisoned by Hapalopilus nidulans mistook it
for an edible Fistulina hepatica, like this one.

Fistulina hepatica has separate, unfused tubes and the
flesh is much more meat-like than Hapalopilus nidulans.

References & Resources:

Michael W. Beug, Polyporic Acid in Fungi: A Brief Note, McIlvainea, Vol. 21

Kraft, J., S. Bauer, G. Keihoff, J. Mieersch, D. Wend, D Riemann, R. Hirschelmann, H-J Holzhausen, J. Langer. 1998. Biological effects of the dihydroorotate dehydrogenase inhibitor polyporic acid, a toxic constituent of the mushroom, Hapalopilus rutilans, in rats and humans. Arch Toxicol 72:711-721.

Villa AF, Saviuc P, Langrand J, Favre G, Chataignerl D, Garnier R: Tender Nesting Polypore (Hapalopilus rutilans) poisoning: report of two cases. Clin Toxicol (Phila); 2013 Sep-Oct;51(8):798-800

Dyeing with Hapalopilus: http://www.allfiberarts.com/library/mushrooms/hap-rutilans.htm

The only other known cause of purple urine

Species descriptions of Hapalopilus nidulans: 

Mycoquebec (as Hapalopilus rutilans)

Mushroom Expert