synan's picture

Caloplaca aractina

Observed: 28th May 2013 By: synansynan is knowledgeable about Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichens
Caloplaca aractina (4)
Caloplaca aractina (2)
Caloplaca aractina (3)
Caloplaca aractina (9)
Caloplaca aractina [habitat] (21)
Caloplaca aractina [habitat] (8)
Description:

Established colony on hard siliceous boulders near a cliff of intrusive granodiorite in the mesic supralittoral. New to Wales.
Edit: additional photos added (taken 25/08/13).

Identifications

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Species interactions

No interactions present.

Comments

jhn7's picture

Brilliant!

I can't wait for Alan to see this! I'm afraid I cannot agree because I have never seen it but I did a web search and I can see how rare it is.

Janet
Certificate in Contemporary Science (Open)

synan's picture

Thanks, Janet

I wouldn't agree either. I should have added that I haven't had this officially confirmed yet. Even so, I am convinced.

Nigel

AlanS's picture

Hmmmm

I would really like this to be C. aractina, but I cannot quite convince myself. My first thought was C. chlorina and I cannot shake that thought off.

First of all, C. aractina is a very rare, Red Data Book species in Britain, confined so far as anyone knows to the Lizard Peninsula, mostly on serpentine. There are a very few ancient records from elsewhere, but according to Bryan Edwards (Caloplaca expert) in the text to fascicle 6 of the Lichen Atlas of the British Isles (British Lichen Society), these have mostly proved to have been C. ceracea. At present, the Lizard seems to be the only British site with confirmed records.

I don't think the apothecial margins we see here correspond to C. ceracea, but nor do I think they match C. aractina. Leif Stridvall's website contains excellent series of photographs of both C. aractina and C. chlorina, and Nigel's photographs seem to have the apothecial margins of the latter. C. chlorina is usually isidiate, but the isidia can be sparse, very small, and sometimes absent.

Apparently a microscopic character to separate the two species lies in the tips of the paraphyses, swollen in C. chlorina, scarcely so in C. aractina.

So I don't want to squash the possibility of this being C.aractina. It is sufficiently like it for the possibility to be considered very carefully. But I do suggest, Nigel, that it is C. chlorina. Sorry.

Alan

synan's picture

Time will tell

As it happens, I have been in touch with Bryan since posting and my sample is on its way to him. I will let you know the outcome.

Thanks for your thoughts on C. chlorina, which has been my stumbling block with this. I had convinced myself it couldn't be that species, but another look at the Stridvall photos has me wondering again. I might be deluding myself, but I think the structure of the thallus, especially at the margins, looks more like the C. aractina photos.

The description of C. chlorina in The Lichenologist [43(2): 113–135 (2011)] gives "always sorediate/blastidiate"; there are no soredia/blastidia/isidia on my small sample, though I would probably have overlooked them in the field. The thallus isn't K± pale violet in section.

On the other hand, the end cells of the paraphyses are on the swollen side. Unfortunately I don't have fertile C. chlorina to compare with.

Anyway, I hope we'll soon know for sure.

Nigel

Edit: On the subject of C. chlorina, might the following be it?

http://www.ispot.org.uk/node/315189

AlanS's picture

Good to know

Good to know this has gone off to Bryan. I quite see your reasoning even if I am deliberately staying unexcited. I had forgotten that C. chlorina was covered in the C. cerina paper, and as they show pretty conclusively that C. isidiigera is a separate species, it will be interesting to see how that pans out.

One of the sources I read (forget which one now) regarded the development of soredia/blastidia/isidia in C. chlorina as variable and sometimes hardly apparent, though I see these are emphasised much more in the description you cite. Looking at a series of close up photographs of undoubted C. chlorina (with apothecia) I took last summer on a church wall, I see some of the thalli were very strongly sorediate-blastidiate, while other thalli within the same composite patches had sparse blastidia and some areoles perfectly smooth.

Your third photograph suggests the thallus surface is granular in places - could these be blastidia?

Anyhow, I await further news. You make a good case.

As for your other observation, I don't think I'm much good yet at recognising C. chlorina without apothecia, but I am pretty sure you were right. No way was it a Dermatocarpon! If you post your own ID, even with a trace of doubt, I would agree.

Alan

synan's picture

The verdict

Good news: the specimen is fine for C. aractina, I am very pleased to report!

I hope to be back on the Llŷn Peninsula at the end of the month (after a rare trip to Scotland) and will no doubt revisit this site. I agree that the third photo looks a bit granular, so I'll see if I can make sense of that and get a better idea of how well established the colony is. I think the coast near Trefor and Pistyll is worth checking too, but the boulder-strewn pebble beaches are hellish to walk on.

Nigel

jhn7's picture

Could be how it has established there?

With little foot traffic to disturb it. Or perhaps an isolated colony that has not been seen by someone interested in lichen.
Terrific news!

Janet
Certificate in Contemporary Science (Open)

AlanS's picture

Excellent

Since my previous, let's-not-get-too-excited comments, I have been to Cornwall and in a not too successful visit that involved too much heat, too much gorse and too little water, I did manage to see C. aractina in one of its good sites. I had to admit it looked exactly like your photographs!

By the way, glad to see you have your 'knowledgeable' badge at long last. [Dunno if I have any credit for this but I did propose you earliet this year. Long overdue.]

I might get time to add C. aractina to my site this month, maybe, and plan a link to this observation.

Health permitting, I also have Ben Lawers in my sights. So if you meet somebody else crouched over true Peltigera ponojensis ...

Alan

synan's picture

Badge

Yes, I did mean to contact you. I have you to thank for the badge and the journey that led to it. In my response to Martin Harvey:

"It was Alan's contributions on iSpot that ignited my interest in lichens, an interest that now takes up most of my precious leisure time!"

So, a big thank you. I'm both flattered and thrilled.

I look forward to your C. aractina page and any other additions.

With much trepidation, I leave for Ben Lawers this morning.

Nigel

AlanS's picture

Addiction

Oh dear, I do apologise.

Too late I discovered lichens are addictive, but now it appears this addiction is contageous. I'm sorry.

I warn you, it can only get worse. Only a couple of days ago I committed myself to a hideous sum of money for the two volumes of the new German lichen flora. And watching TV becomes increasingly impossible, as murder most foul is taking place and I'm trying to identify the lichens on the out-of-focus tree in the background. Maybe, in time, there will be some kind of support group set up for sufferers such as ourselves. We can but hope.

Anyhow, good luck on Ben Lawers.

Ben Lawers was the scene of my only mountain accident. I was staggering around, head pouring with blood.
And I hadn't even left the car-park.

But with luck you should do better.

Alan

AlanS's picture

badge & e-mail

Checking some recent back e-mail I see Martin did keep me in the loop (or tried to ...).

Alan

Ginny B's picture

Very exciting!

Very exciting to read about this one! As Janet says, terrific news.

What part of Scotland are you visiting, Nigel? Any expectation of finding another wonderful rarity in this part of the world?

Ginny

synan's picture

Loch Tay and Ben Lawers

The mountain is well recorded and has quite a reputation for rare and obscure species. Even if I survive the midges and the ascent, I expect to be out of my depth with whatever lurks up there.

Nigel

Ginny B's picture

A lovely spot

A lovely spot to visit but I don't envy you the midges at all! I wish you great success and fun on the mountain. Hopefully the higher you go the less the midges will be around.

Ginny