A Lichen-liking Fungus: Illosporiopsis christiansenii

I like complex fungal stories, especially ones you can hold in one hand. Sometimes these stories are mysteries that need to be solved – and I get to be the detective.

This particular story starts late last fall when my friend Ulli and I were poking around with our dogs in a hardwood forest. We found this and that. And then we found something odd. It was tiny. It was sort of fluffy or fuzzy and fragile. But the best part was that it was hot pink – the same gaudy hot pink as chewed Dubble Bubble gum. It was growing along with lichen on a knobbly, gnarly growth on a fallen branch. The crown of the tree above us sported a plethora of the same knobbly, gnarly growths (which I've found before). 

I didn't know the names of any of the characters except the tree, which I'd thought was an ash. Except it turned out not to be an ash, so I didn't even know what the name of the tree was.

Tree's Bark 

Sorry for crummy picture.

Knobbly, Gnarly Growths in Crown

Knobbly, Gnarly Growth Close-up

Lichen and Pink Stuff on Knobbly, Gnarly Growth

Mystery Pink Stuff on Knobbly, Gnarly Growth

Mostly I wanted to know what the pink stuff was. Was it some sort of fungus? An anamorph, or asexual form of a fungus, perhaps? Maybe even an anamorph of a fungus that had caused the knobbly, gnarly growths on the tree? Or did it have something to do with the lichens it was growing so close to, though did not appear to be actually growing on? 

Asexual Sphaerosporium lignatile anamorph

I've written about anamorphs before (see here). Sphaerosporium lignatile is a common one in central Ontario that I didn't include in that post. But, macroscopically, it has similarities to the pink things: it's tiny; it's texture is sort of similar, though wetter; and it's fragile. But it's not bubblegum pink; it's orange-yellow. It was similar enough, though, to convince me that the pink stuff was most likely an anamorph. 

Sphaerosporium lignatile produces tiny cushions 
that are, essentially, piles of thousands of conidia.

Sphaerosporium lignatile conidia called chlamydospores

The problem with finding names for asexual forms in the fungal world is that it's way, WAY easier to identify one if you know what its teleomorph, or sexual form, is. I have multitudes of dried samples of still-unidentified anamorphs that proves this. Would my pink guy be relegated to this sad group of nameless characters? 

Not if I could help it. Unless I had found the only ones that had ever existed, which I knew was extremely unlikely, I was sure I could find its name since its startling pink popped it out of its lichen and bark surroundings in exactly the same way a crumpled up Dubble Bubble wrapper would pop out among fallen leaves on a forest floor. It seemed probable, rather than simply possible, that it would not only have a name, but that it would also have a strong presence on the internet. So, with devil-may-care optimism, I tried Googling pink anamorph. 

What a mistake! Apparently the word "anamorph" has been usurped for many new uses that have nothing to do with fungi. 

Results of a "pink anamorph" image search

I tried typing in pink anamorph fungus. This time there were actually a few images of fungi, including at least one pink anamorph I already knew, Coryne dubia. But nothing looked anything like my pink things.

Coryne dubia, the anamorphic form of Ascocoryne 
sarcoides, is a fair size and rubbery.

Maybe it would help if I found a name for whatever had caused the knobbly, gnarly growths. I figured this should be easy to find since a) the growths are conspicuous, and b) people are curious about such things, especially if such things have appeared on a tree in their yard.  

So, (still thinking my tree was an ash), I went on a merry Google goose chase looking for ash galls. 

I found lots of pictures of ash galls...but they were all Ash Flower Mite Galls. Ash Flower Mite Galls look prickly and lightweight, and dangle on flower stems. Nothing like my tree's knobbly, gnarly, woody growths. 

Ash Flower Mite Galls
(Whitney Crenshaw, Colorado State University, Bugwood.org)

Maybe a another word would help. How about ash burls? That got me about a thousand hits, all of them woodworker sites. I tried adding the qualifier, little, and instantly found out that woodworkers use all sizes of burls. Searching with tree crown added didn't help either. 

It was starting to occur to me that I had the wrong tree. Maybe it wasn't an ash. Didn't I take a picture of its bark? I downloaded my photos and took a closer look at the bark than I had in the bush. Aha! Not criss-crossy enough to be ash. That's when I remembered that earlier on our walk Ulli had pointed out a hickory nut hollowed out by a red squirrel. It was noteworthy because we don't see them very often up here in central Ontario. 

Bitternut Hickory (Wikipedia)

Generally, I'm pretty good with my trees but, up until then, hickory hadn't really been on my tree radar. I see their nuts on occasion, but I've never been able to pinpoint the trees they came from. I think the squirrels covet hickory nuts and are willing to travel a distance to gather them, then carry them all the way home to savour later. Like me driving to the city to buy something obscure, but delicious, like tinned cod liver packed in its own oil.   

I got out my tree book (yes, I still use books) and quickly confirmed that the tree was indeed a hickory, specifically a Bitternut Hickory (Carya cordiformis). Mystery #1 solved. 

Now that this character was named, it was a simple matter to Google hickory gall and – bingo! – I immediately discovered that the growths are called "Hickory Crown Galls."

Bitternut Hickory infested with Phomopsis sp.

And, as I suspected, Hickory Crown Galls – or Cankers, are, indeed, caused by fungi. The culprits are members of the genus Phomopsis.  

So was the pink stuff an asexual form of a Phomopsis? 

Not a chance, since it turns out that Phomopsis species are, themselves, asexual entities, or anamorphs. Their teleomorphs (sexual forms), are all members of the genus Diaporthe, which themselves are devilishly difficult for an amateur to identify. So, at this point, since more than one species of Phomopsis can be found on hickories, I have to be satisfied with a generic solution to Mystery #2: the knobbly, gnarly woody growths are caused by Phomopsis sp.. Though some sites state that Phomopsis is harmless to the tree, it has also been associated with decline in the crowns of infected trees (see here).  

Hickory Crown Gall caused by Phomopsis sp.

I was still stuck with my primary mystery: What the heck was the pink stuff? 

The microscope is rarely my first stop on a search, but it was time to stop dilly-dallying on the internet and look at the pink things more closely. I prepared a slide and took it upstairs.

Well – close up it was just FABULOUS!! The pink matter under the slide cover had separated out into little bundles of cartoon characters!! There was nothing else. There were no basidia, no asci, no sexual reproductive parts of any kind. Just friendly little bunches of cartoon characters. Cartoon-character asexual spores, or conidia. Which made it an anamorph. Which also left me back at square one.

Aren't they jolly?

Each of the bundles (sporodochia - top) is made up of a 
chain (helicospore) of asexual spores (conidia). 

So how about about the lichens? Do lichens, produce anamorphs? I know a little bit about lichens, but I had no idea if the fungal part of a lichen ever produced anamorphs. A search of pink lichen anamorph got me lots of pictures, including many images of two different lichens – Cryptothecia rubrocinta and Dibaeis baeomyces. Both are lovely, and feature the colour pink, but they weren't what I was looking for. 

Cryptothecia rubrocincta, or Christmas Wreath Lichen (Wikipedia)

Dibaeis baeomyces, or Pink Earth Lichen (Wikipedia)

Are lichens attacked by fungal parasites? I tried pink lichen parasite.  

And – ta da! – it took maybe a nanosecond for Google images to start displaying bubble-gum pink characters nestled amidst lichens. But wait! It wasn't an instant slam dunk, because it turns out there are two completely different pink fungi that are both lichen parasites, or lichenicolous: llosporiopsis christiansenii (syn. Hobsonia christiansenii) and Marchandiomyces corallinus (Illosporium corallinum). Macroscopically, the two fungi are teasingly alike. But, though both are anamorphs, I. christiansenii  is the asexual form of an unknown ascomycete that produces conidia, while M. corallinus is the asexual form of an unknown basidiomycete that, importantly, does not produce conidia. Finally, Mystery #3 solved!

I. christiansenii's favourite hosts are a number of common, tree-loving members of the genus Physcia (M. corallinus likes these, too!), and sometimes the egg-yolk coloured Xanthoria parietina. Since I wanted to know who the host of my Illosporiopsis was, I spent some time with two of the lichens growing on the gall. The egg-yolk yellow one, Xanthomendoza sp., is not known to be attacked by I. christiansenii. The other, P. millegrana, is. Mystery #4 solved!

Physcia millegrana with spore-producing apothocia (top)
that produced the ascospores & asci (bottom).
The green cells are the cholorophyll producing algae. 

Though I thought at first the yellow/orange lichen on the gall 
was Xanthoria parietina, it's actually Xanthomendoza sp.. 

You're probably shaking your head at my convoluted, maybe even ass-backwards, method of going about finding the name of this shocking-pink character. My only real excuse is that, of the five tiny patches of this fungus, four appeared to have no affiliation with any of the lichens growing on the gall. And even if they had been clearly growing on the lichen, I did not yet know – though should have guessed – that there are MANY fungal parasites of lichens (more than 1,800 species described!).

But, if I'd been clever enough to have started my search with either pink lichen parasite or pink lichen anamorph, I wouldn't have this complex fungal story to tell. 

It turns out that I. christiansenii isn't particularly rare. In the last few 
weeks both Ulli and I have found new specimens. When it's wet, like this 
one, it looks really similar to images of Marchandiomyces corallinus. 

References

Juzwik, Jennifer & Haugen, Linda & Park, Ji-Hyun & Moore, Melanie. (2008). Fungi associated with stem cankers and coincidental scolytid beetles on declining hickory in the upper midwest.

R. Lowen, B.L. Brady, D.L. Hawksworth & R.R.M. Paterson, Two New Lichenicolous Species of Hobsonia, Mycologia 78(5): 842 (1986)

D. Lawrey, James & Diederich, Paul. (2003). Lichenicolous Fungi: Interactions, Evolution, and Biodiversity. Bryologist. 106. 80-120. 10.1639/0007-2745(2003)106[0080:LFIEAB]2.0.CO;2.

Lichenicolous fungi at lichenicolous.net 

Marchandiomyces corallinus

Cryptothecia rubrocincta, the Christmas Lichen on Tom Volk's excellent fungi site

Choosing Between Sex and Celibacy: Anamorphic Fungi (I)

Unlike for you or me, it's not unusual for fungi to reproduce both sexually and asexually. One of the ways they do this is by producing two or more different kinds of spores. It’s a way to hedge their bets: if conditions aren’t optimum for sexually produced spores to germinate, perhaps things will work out better for asexual spores. 

Production of asexual spores of one sort or another is a common strategy for ascomycetes. Some genera, such as Hypomyces, produce simple asexual spores called conidia that bud off the tips of conidiophores. 

The asexual conidial stage of the parasite, Hypomyces hyalinus, deforms Amanita species.

Hypomyces hyalinus conidia bud off conidiophores 

Here is the less commonly seen sexual
reproductive state of Hypomyces hyalinus

Asci and ascospores of Hypomyces hyalinus

Another ascomycete, Hyalorbia aff. inflatula, clothes itself in more complex conidial “hairs” that are so large they're visible to the naked eye (well, maybe to an eight-year-old’s naked eye—Hyalorbilia are tiny). 

The "hairs" on the outer surface of these Hyalorbilia
are actually conidia (asexual spores).

Ascospores (small) and conidia (big) of Hyalorbilia aff. inflatula

Asexual spore production is less common in basidiomycetes, but it does happen. Many Dacrymyces produce conidia that either develop in chains or bud off sexual spores like little balloons. For variety, though, fungal rusts take the cake as asexual spore producers: some species supplement their basidiospores with four different types of asexual spores (see my rust post here).

Some jelly fungi, including Dacrymyces capitata, produce conidia.

The sexual basidiospores of Dacrymyces capitata sprout conidia lollypops. 

Anamorphs

Some fungi produce macroscopic structures specifically for this asexual spore production—structures that look nothing like those that produce their sexual spores. These often peculiar "imperfect" forms are called anamorphs. 

Anamorphs can be so different from their other halves that early mycologists gave them their own names. Recently, though, there has been a movement to taxonomically amalgamate these anamorphs with their sexual teleomorphs, with precedence being given to their teleomorph names. Which, if you ask me, is too bad—I hate giving up complex bits of Latin that I've put considerable effort into memorizing. 

Here are some of my favorites—and I'm going to buck the trend and use their anamorph names followed by their teleomorphs in my headings, even if the former has been deprecated.

Ptychogaster albus (Postia/Oligoporus ptychogaster)

I was on a Mycological Society of Toronto foray this fall when I spotted what I thought at first was a clutch of immature Hericium erinaceus sprouting from a log. It would have been a good find: H. erinaceus (Pom Pom, Lion's Head) is the least common Hericium in Ontario and is, like its brethren, a delectable edible. But wait! Hericium species only grow on deciduous trees, and this was a dead pine!

Pom poms, but not Hericium erinaceus

What I'd stumbled on was a clutch of Postia ptychogaster anamorphs, which used to be called Ptychogaster albus. Though I've found it before, this was an exciting find because a) there was a whack of them in pristine condition and, b) the collection included the biggest one I'd ever seen—a good 6 cm in diameter, or about three times as big as any I'd ever found before.

This is the "giant" 6 cm. "Ptychogaster album."

Postia ptychogaster anamorphs are made up of a tight ball of hairy or fibrous radially aligned tissue that's fuzzy on the outside, making them look much more like pom poms, in my humble opinion, than any toothy Hericium erinaceus. 

Young Postia ptychogaster anamorphs frequently excude guttation droplets.

When these fuzzy bundles are young, like the batch I found, they're moist and often produce guttation droplets, but as they mature, they dry out and turn into dusty conidia-filled powder puffs.  

As it ripens, the anamorph gets more and more brown and airy as conidia form.

Conidia and "hair" of Postia ptychogaster anamorph

Conidia production had clearly not yet begun inside the ones I found since they were all still whitish. I bent down to photograph them. That's when I saw that some of them were actually white projecting shelves: Not only had I got myself a bunch of anamorphs, but I'd also found five Postia ptychogaster teleomorphs!

Top & bottom of the elusive Postia ptychogaster teleomorphs

I should make this clear—there's nothing particularly exciting about the way Postia ptychogaster looks. Basically, it's a small, white, resupinate or pileate polypore with angular pores (usually 3-4/mm). It doesn't stain when damaged. It doesn't smell like anything. It's probably not even edible. But—and this is a big but—even though its anamorph is regularly collected, the teleomorph is almost never seen. 

Needless to say, I was thrilled. I was even more thrilled to get one to produce spores at home.

Postia ptychogaster spores

Postia ptychogaster clamps

Xylocoremium flabelliforme (Xylaria cubensis)

Xylocoremium flabelliforme is the anamorph of Xylaria cubensis.    

Most Xylaria species produce copious amounts of conidia in the spring (the pale powdery stuff that coats them when they're growing). The conidia of these species all look pretty much the same, so they're useless for ID purposes. To get a good name, you have to catch them when they're producing their black sexual spores on the same structures later in the season. An exception is Xylaria cubensis. Instead of powdering itself with conidia in the spring, X. cubensis produces a distinctive-looking conidia-producing anamorph. These anamorphs can sometimes be seen near old or new teleomorphs, which makes naming the teleomorph a cinch.

The pink "frills" of Xylocoremium flabelliforme 
are always hard and dry when I find them.

The anamorph, still called Xylocoremium flabelliforme, is weird enough that it's unlikely you'll confuse it with anything else. It appears in the spring on hardwoods, has a short black Xylaria-like stem topped with a firm to hard, pale salmon "frill." It doesn't exactly look fungal; it looks alien.

Though I've found these fancy-pants little guys a number of times—always on alder in my wetland—I have never come across its teleomorph, nor, to my knowledge, have my intrepid Mycoquebec friends to the east, though they have numerous samples of the anamorph displayed on their indispensable website. The teleomorph is apparently not uncommon farther south in the US and in the tropics, but it would be a coup to find one here. (See Mushroom Observer for pics of the teleomorph of Xylaria cubensis.)

I do not pretend to understand why Xylaria cubensis refuses to produce its teleomorphs in Canada. If anyone has found one up here, or has a theory for why they can't be found, I'd love to hear from you!

(All photographs copyright Jan Thornhill)