Caloplaca & Cladonia ID Help Please

[Lancashire Lad]

Found yesterday on a dry stone wall (within metres of each other).

A Cladonia - possibly C.diversa?


A Caloplaca? (I thought I would be able to ID this myself, but the more I look at images, the more uncertain I become ).


Regards,
Mike.

[AlanS]

Hi Mike,

Excellent photographs, as you always manage. And it does make identifying from photographs so much easier!

The Cladonia is C. fimbriata.
Golf-tee shaped, completely covered with fine, powdery soredia, no sign of the bright red blobs (tiny pycnidia or larger apothecia) that characterise C. diversa.
This is a particularly good representation of "ideal" C. fimbriata. Sometimes it is not so easy.

The yellow lichen is almost certainly a Candelariella.
I think it is well developed C. vitellina, especially as it has a couple of small apothecia.
When developed like this it can be very difficult to separate from C. coralliza (which always grows where birds perch, e.g. the highest point of a drystone wall) but the granules seem to be the right shape for C. vitellina and I don't recall that C. coralliza ever produces apothecia. (Replying from work* just now, so no books at hand to check.)

*break from resit exam marking

Candelariella is very easily confused with Caloplaca but differs in NOT reacting purple with KOH and in the different spores. At times the field chemical test is essential.
This is the reason I have recently been leaving small purple spots on various church walls in East Anglia. (The purple fades drab brown reasonably quickly, no real environmental consideration as long as not used on anything very rare, though I suppose they could spark a few aliens rumours.)

Alan

[Lancashire Lad]

As always, thanks very much for your detailed response Alan. (I just hope that some of it sinks into the old grey matter for future recall).

I can see that I'm going to have to obtain some KOH.
(Sometimes I wish I had never taken up photography - because if I didn't keep photographing these things, I wouldn't need to be so obsessive about trying to identify them afterwards. ).

Best regards,
Mike.

[Lancashire Lad]

Originally Posted by AlanS

....I think it is well developed C. vitellina, especially as it has a couple of small apothecia.
When developed like this it can be very difficult to separate from C. coralliza (which always grows where birds perch, e.g. the highest point of a drystone wall) but the granules seem to be the right shape for C. vitellina and I don't recall that C. coralliza ever produces apothecia....

Hi Alan,

Just in case it might help confirm things, small patches of this were found over quite a large expanse of the wall, but generally on the sides of the stones. I don't recall much at all being on the top of the wall/stones, where birds might have been likely to stand/perch. (The photo is of a patch on a stone about half way up the side of the wall).

Regards,
Mike.

[AlanS]

Hi again Mike,

I am now at home, looking at your photographs with a better monitor and able to check a couple of books.

I think now that your Candelariella IS C. coralliza.

Candelariella coralliza (images of British lichens)

Compare:
Irish lichens - Candelariella vitellina.
It is not the same.

C. coralliza does, rarely, have apothecia (they are even shown in 'Dobson') and the more or less spherical granules cover the entire surface. Even the fragments of young thallus are seen in your photograph to be granules, whereas C. vitellina starts out with aggregations of flattened, tiny plates. C. vitellina is very variable (maybe troubling so) but this would have to be VERY well developed. Even on the side of the wall, I think it has to be C. coralliza.

Alan

[Lancashire Lad]

Originally Posted by AlanS

Hi again Mike.....Even on the side of the wall, I think it has to be C. coralliza. Alan

Thanks Alan, much appreciated.

Regards,
Mike.

[JennyS]

Candelariella is very easily confused with Caloplaca but differs in NOT reacting purple with KOH and in the different spores.

I get a crimson-red rather than purple when using K on Calaplaca (and Xanthoria) species. Dobson gives K+ crimson for them all whereas the 'Lichens of GB and Ireland' gives K+ purple.
Is this just two different ways of describing the same colour or is a slightly different reagent being used which is producing a slightly different coloured result?

[AlanS]

Originally Posted by JennyS

I get a crimson-red rather than purple when using K on Calaplaca (and Xanthoria) species. Dobson gives K+ crimson for them all whereas the 'Lichens of GB and Ireland' gives K+ purple.
Is this just two different ways of describing the same colour or is a slightly different reagent being used which is producing a slightly different coloured result?

Jenny, with the same reagent bottle of KOH I get colours that vary from crimson to dark purple, in both Xanthoria and Caloplaca. I haven't carried out any careful comparative tests - just assumed that random factors affect the colour a little.

Alan