Lichen on pebbles at Hatfield

[FungiJohn]

Hello all

On a recent visit to Hatfield in Yorkshire with Les and John we found this Lichen growing on stones and pebbles.

I'm certain this is Rhizocarpon concentricum but not sure if other(s) with it are the same!



Other(s):





Close up:



Any help or comments as always much appreciated.

John et al

[diggleken]

Good luck John,
these look tough to me, but certainly concentricum seems to be a fair estimate of the first one.
Rhizocarpon seem quite difficult........................
Cheers
Ken

[FungiJohn]

Originally Posted by diggleken

Good luck John,
these look tough to me, but certainly concentricum seems to be a fair estimate of the first one.
Rhizocarpon seem quite difficult........................
Cheers
Ken

Thanks Ken

I may have a look at these under the scope after I finish with the BMS Asco finds.

All good fun

John

[jaybie]

Looks like you've got a bit of work on your hands John.
JohnB

[FungiJohn]

Originally Posted by jaybie

Looks like you've got a bit of work on your hands John.
JohnB

Yes John. I'm going to build a small rockery from them

John

[AlanS]

Hello John

Welcome to the wonderful world of lecideine lichens. Once upon a time they were all grouped in the genus Lecidea, but now the genus has been much split up, meaning that instead of one genus that is impossible to identify to species in the field, or from photographs, we now have several.

If a section of a fruitbody provides mature asci, then there is a chance of getting it to species. (In much the same way that there is a chance one's lottery ticket could win.)

There are a lot of very similar species, and very often apothecia, no matter how well-formed they look macroscopically, are NOT mature.

So ok, I am not going to throw names at any of these. The introduction to Lecidea in Dobson is very useful - diagrams of ascus types on page 233 (edition 5) and the tabulation of genera on the following page, then its a question of settling down with a microscope, the usual chemicals, and the keys/descriptions in The lichens of Great Britain and Ireland.

Your photo 1 is, I am afraid, NOT Rhizocarpon petraeum (formerly 'concentricum'). That has innate apothecia (i.e. set within the thallus), while your photograph shows the apothecia to be superficial, i.e. on rather than in the thallus surface. It looks like a Porpidia to me, and it could well be P. crustulata, which not unusually forms concentric rings of apothecia. But there are over 20 other species in the genus.

With the apothecia being constricted beneath and somewhat wavy-edged, I did wonder about the Lecidea auriculata complex for photographs 3 and 4, but the thallus looks too well developed.

And that is as far as I can go. Some of these species are highly photogenic, but getting a name afterwards ....

Alan

[FungiJohn]

Hi Alan

Many thanks for this. I somehow guessed it wouldn't be that easy!

I'll lay them on the 'rock pile' and maybe go back to them when I have a hard time with an Inocybe under the scope

John