Funky Fungi

Today was warm and muggy, by Skye standards at least. It was 17 or 18 degrees, but felt decidedly warmer when the sun emerged partway through the afternoon. I took advantage of the lack of rain and hit the rear lawns with a vengeance. Two lawns in and it started raining... Happily it soon stopped and by the time I'd finished mowing, strimming and faffing around, the back of the hotel was looking quite a bit neater than before. After work I headed to the local shop and treated myself to an ice cream, why the hell not. I plopped myself onto a low wall and enjoyed my Magnum, or whatever it was, whilst staring into the lush undergrowth on the other side of the wall. I soon spied a large number of Dasineura pustulans galls on Meadowsweet leaves, my first sighting of it this year. Ordinarily these are far outnumbered by the other Meadowsweet gall-midge Dasineura ulmariae, but oddly enough I couldn't see any of those at all.  

Early-stage galls of the midge Dasineura pustulans, looking like tiny green fried eggs

And then I nearly dropped my ice cream in surprise. 

There's a lovely looking rust fungus that I've been half-heartedly keeping an eye open for ever since I learned of its existence a couple of months back. I say 'half-heartedly' not because I didn't want to find it (I really did!), but 'half-heartedly' because I never expected to see it on Skye. And yet here I was staring at it growing very merrily just a few feet away! I took my usual barrage of pics without realising I was on a wrong setting, so none of the images came out particularly brilliantly. Hey ho.

What a complete beast of a rust!!!

This is Puccinia commutata which infects Common Valerian, a common enough plant in damp and shaded places across much of Skye. I'm fairly certain I've never seen this rust fungus before today, not even unwittingly, despite its host being widespread and common. I do like the rust fungi and there's just no way I wouldn't have chased this one down had I seen it before. 

For anybody into their rusts (and I mean who wouldn't be?!?!) have a look at this fantastic pdf and scroll down to page 33 to read a little background info on Puccinia commutata. They list it as Near Threatened, though they also note that it may be spreading and has recently been found to be present on Red Valerian along the south coast of England. We don't have Red Valerian on Skye, but if I ever make it back down south I'll be checking for the rust on that too. Red Valerian also hosts a nice psyllid that we don't get here. 

Pleased to have stumbled across this lovely rust, I continued on my way back from the shop and soon spied an even more spectacular rust, though it's one I do see quite often. This is on Common Nettle rather than Common Valerian and is quite probably in a nettlebed near you too.

Again, it's a bit of a beast for a rust fungus!

This is one of the Puccinia urticata complex, of which there are several. Each species in the complex alternates between using nettle as a host and using one of several sedge species as its other host. The problem for folks like myself is that the fungus is only identifiable when it's on the sedge host. Whilst on nettle they're just not distinguishable from each other. It's all a bit meh, really. 

Sticking with weird-looking fungi, this is from earlier in the week when several of us caught the ferry across to Raasay. This is growing on Blackthorn at the edge of the car park, as spotted by Neil.

Won't be making any sloe gin with those manky things!

These sloes have been infected with the fungus Taphrina pruni and there's a nicely informative page about it here. There were an abundance of these galled sloes in Uig Wood a couple of years back, I ought to go check if there are any to be seen this year too. 

Out on the open hills, Star Sedge is a sometimes common component of the 'scary' (ie sedges, grasses and rushes) element of the ground flora. Some years are definitely better than others, but something to keep an eye out for is the black smut on Star Sedge. Other sedges have their own species of smut (Carnation and Flea Sedges for starters), but they seem far less common. I've never seen either yet. Here's Anthracoidea karii the Star Sedge Smut as seen on Raasay last week

Quite eye-catching really - and a good way to ID the sedge!

The last fungi for this post concern some small black dots that I found growing on dead leaves of Crowberry. The first lot of dots were collected from about 1200ft up Stockval nearly a fortnight back. I'd provisionally identified them as one thing, but Nick had identified them as something else entirely!!

The second lot of Crowberry dots, also growing on dead leaves, were collected from near sea-level on Raasay earlier this week. Nick hadn't gotten much joy finding spores from his sample. Last night I finally got around to doing some spore squashes in an effort to figure out what I'd collected from both sites.

These are the Stockval fungal dots and a (rather enlarged) image of a single ascus from it

You should hopefully be able to see that the blackish fungal fruiting bodies are sitting proud on top of the leaf surface. Underneath a miroscope it's easy to see that they resemble tiny shrivelled 'jam tarts' (to nab a description from the lichen folks!) These are what's known as apothecia. Each of these fruiting bodies is around half a millimetre in diameter, so not exactly large...

And these are the Raasay fungal spots, rather different from the Stockval specimens in several ways

Just like Nick, I too couldn't find any asci or spores from this sample

Compare the black dots on these leaves to the black dots in the image further above. Hopefully you'll agree that they aren't sitting proud of the leaf surface and that they don't resemble tiny shrivelled jam tarts. They are still fungal fruiting bodies, but these have essentially pushed their way through the leaf surface and are still immersed inside the leaf tissue itself. These are what is known as epiphyllous perithecia, somewhat different in structure to apothecia. There's a very good lichen-orientated page showing the differences between apothecia and perithecia here. Don't be confused that I'm sending you to a lichen page to learn about structures in fungi. In this particular instance they're all the same thing anyway ;-)  

There are several different species of fungi that grow on the dead leaves of Crowberry. Figuring out which we had required a bit of tenacity and much cross-referencing my various texts with online wisdom whilst trying to keep track of the taxonomical upheavals that have occured of late. I was convinced that the Stockval dots were Phaeangellina empetri. Nick however had already identified them as Physalospora empetri, which have epiphyllous perithecia and not the apothecia that my sample so clearly exhibited. I couldn't understand how we'd independently arrived at two very different species.

The Raasay sample I narrowed down to two species: Physalospora empetri or Botryosphaeria hyperborea, the differences being that P.empetri has a refractive ring at the apex to the asci whereas B.hyperborea doesn't. Seeing as I couldn't find any asci, I couldn't progress any further than that.

I put all of this into an email and pinged it off to Nick late last night. This morning he replied - 

Ah that's interesting, because I do not have any of the Phaeangellina empetri. I can see the difference between the two clearly from your photos. Instead I have the Physalospora/Botryosphaeria from both Stockval and Raasay! I'll have another look to see if I can find apical rings.

That neatly solved the puzzle of how Nick, a very accomplished naturalist with oodles of microscope work beneath his belt, couldn't tell the difference between an apothecia and a perithecia! Here's my final pic of the two different dots side by side. The larger Phaeangellina empetri to the left (0.5mm diameter) and the smaller Physalospora/Botryosphaeria on the right (0.2mm diameter).

So there you go, had I not treated myself to that ice cream this afternoon, this post would never have happened. Serendipity at its finest.