Lichen identification

Netuser60 · #1 (**permalink**) 02-07-2009, 10:48 AM

Can anyone identify this lichen, found growing on the underside of a very damp, probably acidic, boulder pn the bank of an upland (250m) stream in Wales? Thanks!

JennyS · #2 (**permalink**) 02-07-2009, 08:55 PM

Well this is going to be pretty tentative but I think there are at least two different lichen in your photo's...

The green thallus with the white margins I would have said was Bacidia inundata but that has flat, brown fruiting bodies.
Those round pinkish bits don't (as far as I know) belong with B. inundata and they also seem to be on paler-coloured area's of the thallus.

Top left of your photos there seems to be a lichen over-growing moss - there is an illustration of Bacida phacodes in Frank Dobson's 'Lichens' that does show a similar with pale-pink apothecia ...... but I'm not suggesting that as an identification as I could be completely wrong.

(

Alan.... help!)

AlanS · #3 (**permalink**) 03-07-2009, 12:19 AM

Hi Netuser60, welcome to the forum.

I am sure Jenny is right about the (main) lichen being Bacidia inundata.

She is also right that the fruiting bodies (apothecia) do not look quite as they should. My own interpretation of this is that the apothecia do belong to the lichen but that they either have some sort of deposit on them - which happens - or perhaps they are parasitised by some hyphomycete fungus? This would need microscopic examination.

It seems to be a general problem with crusts that the apothecia can be parasitised or become coated, sometimes with algal cells.

So I think Jenny has nailed this, but where I would differ is that I think there is only one lichen present, i.e. the lichen growing over the moss is still Bacidia inundata.

The information at my disposal doesn't list any fungus specific to B. inundata, but no doubt it can be host to various generalist hyphomycetes.

Alan

Netuser60 · #4 (**permalink**) 03-07-2009, 09:54 AM

MANY thanks for the identification ! The apothecia caught my eye as being distinctly pink or pale brown, not dark as in most images of B inundata. Thanks again.

I'm very new to lichens but would like to be able to ID the commonest ones that I see every day on the acidic dry-stone walls here. Any estimates of how many different species one might expect to encounter along ~100m of typical roadside wall in an unpolluted area?