Help to ID please.

[richyrich236]

Hi Guys.

First time on here so please bear with me, I carried out surveys on several trees as part of a course that i am studying, I would be grateful for any help in identifying the following:



A yellow / orange lichen on a Sycamore tree.



This lichen was present on a Plum tree.



A powdery kind of lichen found on a Scarlet Oak tree.



An orange colour moss found on a Manna Ash tree.



Lichen found on a Silver Birch.



Not sure if this should be in this section, this is the trunk of a Monkey puzzle tree with 'ooze' coming out of it.

Any help would be very very much appreciated.

Many thanks

Richard.

[AlanS]

Hi Richard,

Welcome to the forum.

I am, however, going to be a little bit critical. For a start, since this post is mainly about lichens, it would have been better to have posted this in the lichen sub-forum, where those of us who habitually answer lichen queries tend to hang out.

More importantly, you are posting these as part of a survey you are doing for a course, but there isn't much sign of you having done any thinking or research for yourself, which I imagine you are expected to do. I, myself, occasionally supervise students looking at lichens on trees and if I found them not reading up on them and instead posting pictures to the Internet and asking other people to do the work, I would not be impressed.

Of course, if you had a go at them yourself and then wanted us to confirm your identifications, or tell you where you had gone wrong, then there are always those who will be pleased to help.

So my first intention was not to be fully helpful, just as I would not tell my own students the answers immediately, but send them away to have an initial stab at their own problems, including looking at books!

However, it's not like I am giving you a lot of names here, and maybe this is not the main part of your project, so I'll help. If you post any more though, I would expect evidence that you had tried to identify them yourself, larger photographs with better resolution, and basic information, like what part of the country!

So:

Pic 1: the size and resolution of the photograph are poor and there is little visible detail. However, there are so many trees like this now, that it is possible to be reasonably confident of the species.
The yellow species can only be Xanthoria parietina. Some of it does look a bit like something else, but most likely the photograph is simply a bit misleading.
The main grey species is undoubtedly Physcia tenella from the way it is growing.

These two species are now amongst our most common urban lichens. When they cover a tree like this it is indicative of nitrogen (including ammonia) deposition as a result of atmospheric pollution, from car exhaust fumes and/or drift of agrochemicals.


Pic 2.
Parmotrema perlatum (= Parmelia perlatum). Common and increasing with the reduction of sulphur dioxide pollution.


Pic 3.
Yes this is a powdery lichen ("leprose" is the posh term). Again the photograph lacks resolution but it can only be a Lepraria species I think. (There are various leafy ('foliose') species present too, not possible to name from the photograph.)
Unfortunately, Lepraria species are immensely difficult, requiring at least careful examination with a lens, sometimes a microscope, and often sophisticated chemical testing (thin layer chromatography) in a laboratory. If the colour of your photograph is precise, then I suspect it is indeed one of the difficult ones that cannot be named in the field.
The most common species on oak trunks is Lepraria lobificans, but the colour seems not to be correct.


Pic 4.
Dead moss. The resolution of the photograph is too low for me to guess at the species, though others might have a better idea. Something has happened to it. If low on the tree, I would guess that a dog has relieved itself on the tree. If higher, human, If higher still, giraffe?


Pic 5.
Hypotrachyna revoluta
This one is quite common, but not easy. The very untidy look of the lichen (often the case with this species) hinders identification, but a couple of the lobes have 'marginal soralia' (internal tisses burst through and fragment to form the equivalent of asexual spores). This and the general shape and orientation of the lobes and the smooth lobe surface indicate this species. It is flatter on the bark than Parmotrema perlatum, with which it can be confused.

(A complication here is that "Hypotrachyna revoluta" in Britain probably consists of two species, and opinions differ on their relative frequency. This looks like the true species, which in my own experience/opinion is much the more common.)


Pic 6.
Yup, it's ooze (i.e. resin) coming out of the tree. There are some white jelly-fungi that can look similar in a photograph, but in this case, definitely resin.


Alan

[richyrich236]

Hi Alan.

I should have explained a little better, the survey that i carried out was structural assesment, i was just going to try and score a few brownie points by mentioning the lichen / fungi etc.

I did realise once i had posted that it was in the wrong section, apologies.

The photos i had to knock down the size so that they would be accepted, the original size was 6mb and really good quality.

I appreciate the comments and take your comments on board, Would you be able to recommend a good general lichen book, i haven't managed to find one in a shop or library yet, and i don't like to buy from Amazon etc as you dont know exactly what you are buying.

Many thanks, once again for taking the time to have a look and post a comment.

Richard.

[AlanS]

Originally Posted by richyrich236

Hi Alan.

I should have explained a little better, the survey that i carried out was structural assesment, i was just going to try and score a few brownie points by mentioning the lichen / fungi etc.

Ah, yes, that does answer my initial concern and I am glad to have helped.

And yes, I think we all would approve of the idea of fungi and lichens counting for brownie points (even if one suspects they often don't!)

Originally Posted by richyrich236

Would you be able to recommend a good general lichen book, i haven't managed to find one in a shop or library yet, and i don't like to buy from Amazon etc as you dont know exactly what you are buying.

Many thanks, once again for taking the time to have a look and post a comment.

Richard.

Sometime, when I really do have time and am not just posting as a displacement activity from marking, I must write a lichen resources post for the lichen sub-forum - that hopefully someone will make a 'sticky'. This post isn't it.

However: best (and effectively only) field guide:

Frank Dobson (2005) Lichens. An illustrated guide to the British and Irish species. 5th edition. Richmond Publishing.
Good descriptions, most species with a (small) colour photograph, remarkably comprehensive - not easy to find a species not included unless one takes a deep interest in microlichens or is up a mountain. I have a very few quibbles, but in my view it is the best lichen field guide produced anywhere in the world.

(Anyone who looks at the Natural History Book Service website will see that they list as "forthcoming" a lichen guide in the WILDGuide series being written by Peter Lambley. Unfortunately, when I asked him about this, he was intrigued, but denied all knowledge ...)


Fold-out charts (Field Studies Council).
These are remarkably good (and most again by Frank Dobson).
Two are of particular relevance here:

Key to lichens on twigs
Guide to common urban lichens 1 (on trees and wood)

They are cheap and designed for field use and give pictures of the common and characteristic species of the habitat they cover. I found them immensely useful when I was first trying to get to grips with lichens (and I still carry them in my travelling equipment box). Summerfield Books have them.

Websites
With apologies to any others valiantly putting sites together, I suggest three that have good photographs of a good selection of species. They are better regarded as support after coming to an initial identification with Dobson, but each in its own way provides guidance for identification.

British Lichens
A now very large site for lichen photographs, much supported by members of the British Lichen Society. No descriptions with the photographs, but a superb reference source.

Irish Lichens - Index
A stunningly beautiful site created by JennyS who posts a lot in these forums.

Alan Silverside's lichen pages - photographs of British lichens
Er ... yes, OK, it's mine. (Like the two above, non- commercial, so I'm not spamming.) The oldest of these three sites but lagging a bit now (but a major update in prospect).

There is now a 2nd edition of the standard 'professional' British lichen flora (technical, 1046 pages, a few line drawings and no other pictures, out of print just at the moment) and some good foreign books, some very good European websites (see the links page on my own site), but I'll leave those until/if I write a resources post (in the right subforum).

Alan

[richyrich236]

Hi Alan.

Once again, many thanks for the advice and help, just looking into the id guides that you mentioned, i recently purchased a book from Amazon, and it wasn't what i expected it to be, hence my reluctance to buy another without a recommendation from someone such as yourself.

I am planning to take a keener interest in this subject and look forward to speaking with you again.

Kind regards.

Richard.