Saturday, 17 December 2016

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. 


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 albusThough 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)

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