Hoping for a hand...

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Andy
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Joined: Fri May 01, 2020 12:45 pm

Hoping for a hand...

Post by Andy » Fri May 01, 2020 1:39 pm

Hi everyone!!
Sorry that my first post here is asking a favour, but here we go...
I'm a mature student studying in my final year of a Bsc in Environmental Science. My dissertation involves correlations between Lichens and pollution pertaining to varying physical and environmental factors in my local city of Canterbury. I have chosen the four most frequently found Lichens for particular attention. I believe that I have identified these correctly, but I hope someone here will be kind enough to confirm for me. The photos were taken after about a month of solid rain, and while it had been, and still was, raining very hard. I know this may alter the appearance and maybe colour of the Lichens.
Identification made so far with FSC guides and images from google....so expert help would be very gratefully received.
Many thanks!!
Andy
first = Lecanora campestris
Second = Xanthoria parietina
Third = Candelariella medians
Fourth = Haematomma ochroleucum
Attachments
Screenshot 2020-05-01 at 14.36.20.png
Screenshot 2020-05-01 at 14.35.47.png
Screenshot 2020-05-01 at 14.35.13.png
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Glos lichens
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Re: Hoping for a hand...

Post by Glos lichens » Mon May 04, 2020 10:59 am

It is always tricky when lichens are wet. I've just taken these photos of a good Lecanora campestris specimen dry and wet because yours looked a bit too lobate to me, and I couldn't see any fruit to reassure me you were in the right area. As you will see, mine is much lumpier (warted) than yours, lacks the lobes, and you may be able to make out it has a feathery edge (fimbriate prothallus). It is a different specimen, but I also attach a photo from a different roof tile that shows the fimbriate prothallus really well. Can you provide photos at higher resolution? Or better still, read up what features a particular lichen is meant to have, then go and take some more shots making sure that you include those features. A scale is a real help too.
Juliet
Attachments
mm scale. specimen from roof tile. wet. fruiting abundantly.
mm scale. specimen from roof tile. wet. fruiting abundantly.
edge of thallus, wet.
edge of thallus, wet.
dry
dry
edge of thallus, dry
edge of thallus, dry
1_Lecanoracampestris_fimbriate_20200105_142259_1050647.jpg

Mark Powell
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Joined: Mon Jan 07, 2019 4:31 pm

Re: Hoping for a hand...

Post by Mark Powell » Mon May 04, 2020 3:21 pm

I agree with the above from Glos lichens, that your lichen lacks fruiting bodies and appears too lobate for Lecanora campestris. I feel fairly certain that your first image shows Caloplaca teicholyta - at least that is the one that I would investigate further. C. teicholyta is rarely fertile, when it does fruit the apothecial discs are deep orange. You should find that the interior of each individual thallus becomes scurfy-granular. Here are a few images of C. teicholyta.
Attachments
Caloplaca teicholyta 4.jpg
Caloplaca teicholyta 3.jpg
Caloplaca-teicOln.jpg

Mark Powell
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Re: Hoping for a hand...

Post by Mark Powell » Mon May 04, 2020 3:26 pm

In fact my first image showed two similar grey placodioid lichens. In lower centre is a rounded thallus of Caloplaca teicholyta, this is flanked to right and upper left by two thalli of Aspicilia radiosa. The latter has somewhat larger lobes, is a rarer lichen of old limestone and yours will almost certainly be C. teicholyta. Placodioid lichens are crustose. Although they have lobes, the lobes are closely attached to the surface they are growing on and this distinguishes them from leafy (foliose) lichens whose lobes are not entirely appressed to the surface.

Mark Powell
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Joined: Mon Jan 07, 2019 4:31 pm

Re: Hoping for a hand...

Post by Mark Powell » Mon May 04, 2020 3:31 pm

Your second image again shows a crustose-placodioid lichen which rules out Xanthoria parietina (which is foliose). Note how closely appressed the lobes of your lichen are and if you tried to pull the lobes off the surface you would find that they are attached. Your lichen looks like Calopaca flavescens. I will attach an image of C. flavescens and then one of X. parietina for comparison. At this stage please don't get disheartened. Lichens are tricky at first but with a little guidance you should find your way.
Attachments
Caloplaca flavescens.jpg
Xanthoria-pariGW1.jpg

Mark Powell
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Re: Hoping for a hand...

Post by Mark Powell » Mon May 04, 2020 3:35 pm

I can't make anything much out from your third image so I won't try to identify it. I will attach an image of Candelariella medians. Note that it is crustose-placodioid again. It has a paler lemony colour compared with Caloplaca flavescens and a simple chemical test distinguishes the two genera.
Attachments
Candelariella-mediGW1.jpg

Mark Powell
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Re: Hoping for a hand...

Post by Mark Powell » Mon May 04, 2020 3:41 pm

Your fourth image shows a leprose lichen, consisting entirely of (slightly fluffy) minute granules. It is a toss-up between Lepraria lobificans and L. vouauxii. I will attach an image of Haematomma ochroleucum which has a distinct fimbriate margin (like combed cotton wool). The central parts of H. ochroleucum is covered in minutely granular soredia and hence the understandable misinterpretation. Feel free to keep asking if anything is unclear or you get some further images.

Mark Powell
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Joined: Mon Jan 07, 2019 4:31 pm

Re: Hoping for a hand...

Post by Mark Powell » Mon May 04, 2020 3:42 pm

For some reason the image didn't attach. Here is Haematomma ochroleucum.
Attachments
Haematomma  ochroleucum.jpg

Andy
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Re: Hoping for a hand...

Post by Andy » Mon May 04, 2020 3:57 pm

Thankyou very much Glos lichens and Mark Powel, I've obviously asked the right people!
Glos; I see what you mean, the fruiting bodies are very pronounced in your pics, even when wet. The pics were taken in Canterbury city centre and I live a fair way out...a bit too far to claim that I'm just taking exercise at the moment. They were taken with a very high resolution camera so I will try to upload closer resolution pics...I may be able to get an idea of scale as I took some pics of the location of the Lichen on. each building.
Mark: Those pics of Caloplaca teicholyta certainly look more like my specimen. It does seem to be a very skilled job to be able to tell the species apart. Being a complete novice, (and up against it a bit time wise due to Coronavirus....a very minor inconvenience compared to many!) I am very grateful for the help, you've given me a good few suggestions to work with....Very impressed, and not down heartened! I may indeed be back for more help, advice, but for now thankyou very much indeed!!

PS: Glos: Unfortunately, the pics were already 'zoomed in' and the other pics don't offer anything useful with regard to a scale...sorry!

Stay safe have fun!
Andy :D
Attachments
Screenshot 2020-05-04 at 16.48.13.png
Screenshot 2020-05-04 at 16.48.51.png
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