Monday, 20 March 2017

Sorting Elfcups

I had the pleasure of joining Sussex Fungus Group once again on Saturday for a spring foray around Sussex Wildlife Trust's Woods Mill nature reserve. It was a treat for me to go round this site, which I visit all the time, with an experienced mycologist: Nick Aplin. A valuable opportunity to find out what I've been getting wrong!

As I've probably mentioned before on this blog, it's difficult to know what you don't know when you're getting into mycology. And this weekend turned up a classic example.

One of my colleagues, Renzo Spano, first spotted these bright red fruiting bodies  on 1 March and they were still putting on a good show, next to the footpath which skirts the south-western side of the lake, when we visited on Saturday.

Bright red cup fungi, but what species?
I identified them immediately as Scarlet Elfcup Sarcoscypha austriaca, a distinctive species featured in the Collins Complete (photographic) Guide which I'd seen popping up all over social media during the preceding couple of weeks.

What the Collins Complete (photographic) Guide didn't tell me what I would have found out if I'd bothered to look in the slightly more weighty Collins (illustrated) Fungi Guide – is that there's another species which looks almost exactly the same as Scarlet Elfcup S. austriaca: the Ruby Elfcup S. coccinea.

Nick explained that the two can be separated fairly easily with microscopy, so I thought I'd have a go. If you google Sarcoscypha you can find some nice accessible blogs which tell you what to look for, like this one on and this one by Michael Kuo. And Liz Holden tells the story of these two species on the Scottish Fungi website.

Armed with this information, I mounted a thin section of the fruit body in water and placed it under the microscope.

Here's an image of one of the 'asci', i.e. one of the long thin sacs in which the 'ascospores' are formed. There are eight ascospores in this ascus. I think both S. austriaca and S. coccinea can have eight spores per ascus, so this doesn't really get me anywhere but it's quite pretty so I thought I'd stick it in. The red stuff you can see are 'paraphyses' - thin threads which give the fruit bodies their distinctive colour.

Nick had mentioned that a key feature of S. austriaca is that its ascospores sometimes appear depressed at the end. I think this might be a depressed ascospore...

Also, the ascospores of S. austriaca sometimes produce 'conidia' (asexual spores) on the ends. I might have found some of these. Not sure.

Finally, Liz Holden suggests that an easy way to tell these two species apart is by looking at the hairs on the outer surface of the cup. She explains that "S. austriaca has hairs that are almost corkscrewed in appearance whereas in S. coccinea they are straight or gently curved at most."

This is what I observed on the outer surface of the cup. Quite screwy?

With all this additional information, I'm inclined to think my first guess was by chance correct, and this is Scarlet Elfcup S. austriaca. But would be good to get that confirmed by someone who knows what they're talking about...

UPDATE 22/03/2017 - have received confirmation from the Sussex County Recorder for Ascomycetes, Nick Aplin, that this "100 % S. austriaca". Go me!

For the record
Date (of collection): 18 March 2017
Location: Woods Mill
Grid reference: TQ21821365
Record previously entered into FRDBI on 1 March as S. austriaca