Unidentified lichen with black apothecia

[Bruce Williams]

Looking for help with identification.

Firstly, please check out this related thread posted in the main Fungi Forum: Black fungi or lichen plus interesting poo

Here's the original image posted in the Fungi Forum (this image covers an area of 9.5x7mm):



Here's a higher magnification image. I wonder if the indicated off-white, porridge-like 'stuff' is part of the lichen?



Bruce

[AlanS]

Hi Bruce, it would be nice to have habitat info, other than it was next to "poo" (as given in your other thread). (The poo, incidentally, looked more like a regurgitated bird pellet to me rather than faeces, but I am not a poo expert!).

However I am guessing that this was on a wall or artificial structure, in which it looks like quartzite gravel is bound together by mortar or cement?

If so, then with a high level of certainty, the lichen is Lecidella stimatea.

There are a LOT of crustose lichens with black apothecia and, strictly speaking, a section of an apothecium is needed to check the internal colours of the tissues and the ascus characters, but in this case I think we can be confident of the identification. L. stigmatea is a very common species on walls and concrete, so long as some of the material is lime-rich - it very often grows on the mortar of sandstone walls for example.

Thanks for providing an indication of scale, which has helped eliminate some other possibilities.

The porridge-like 'stuff' is indeed the lichen thallus - well developed and characteristic here, though not uncommonly, in this species, the thallus forms within the rock surface.

A superb photograph.

Alan

[Bruce Williams]

Alan - Many thanks for such a detailed and interesting response.

Firstly (just to get it out of the way) the bird poo has been identified (very probably) as a corvid pellet. This fits as I often see magpies and occasionally crows in this same area.

The lichen is growing on a west facing, concrete buttress supporting an exterior wall separating two walkways under a dual carriageway. I think you're pretty much spot-on with the material.

Thanks again for your help,
Bruce

[AlanS]

Oops! I just noticed a vitally important typo.

The name is Lecidella stigmatea (not "stimatea").
Apologies.

What is nice about this photograph (apart from the stunning technical quality) is that it shows the slightly glossy margins to the apothecia very well. This is a field character that helps to distinguish it from the very similar Clauzadea monticola, which is also frequent on concrete and mortar.

Alan

[Bruce Williams]

Thanks for the extra info Alan .

Bruce