Ramalina with medulla K+ pink-red

JennyS
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Ramalina with medulla K+ pink-red

Post by JennyS »

I found a very peculiar Ramalina on a fallen Oak branch in Dorset and then later saw a Twitter post about Ramalina pusilla which led me to look for more details. Height about 2cm, hollow, slightly fragile thallus with a white medulla and many what I'm assuming to be apothecia pending. Soredia and isidia are absent.

After reading the Lichens marins description I checked the medulla reaction of mine and got a (very slow) K+ pinkish-red reaction. Mine looks rather different to illustrations I found but (very tentatively) might this perhaps be something like pusilla?
http://www.lichensmaritimes.org/index.p ... 42&lang=en

Edited to add that Ramalina portuensis is the only Ramalina on the British list with a K+ medulla reaction (K+ orange-red) which mine could be interpreted as when dry - but it doesn't resemble that either!

q Ramalina pusilla 231114 006.jpg
q Ramalina pusilla 231114 007.jpg
q Ramalina pusilla 231115 035.jpg
Jenny Seawright
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Re: Ramalina with medulla K+ pink-red

Post by GERAULT »

It is very difficult to give an opinion on a single specimen (especially if it was collected on the ground and has become unrecognizable) but I think like you that it is a taxon close to Ramalina pusilla with its reaction K+ red (but which varies from pink to red and reddish because there seem to be several chemoforms for this species!). We should see if there are other more typical specimens near the place of collection ?.
Sincerely.

Alain GERAULT

N.B. It is not Ramalina portuensis which is a very different species.
JennyS
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Re: Ramalina with medulla K+ pink-red

Post by JennyS »

Hello Alain and thank you for your reply.
I returned today in the hope of finding more but was unsuccessful - even the lower branches are far out of reach so unfortunately I've no option but to check fallen bits of branches and twigs.

There were several rather odd Ramalina fastigiata/canariensis type thalli but when I checked those the medulla of all were K-.

Oh frustrating but at least something close to R. pusilla remains a possibility and portuensis is discounted!
Jenny Seawright
Neil Sanderson
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Re: Ramalina with medulla K+ pink-red

Post by Neil Sanderson »

Jenny

That is intriguing, not a species I was aware of. See https://italic.units.it/index.php?proce ... ge&num=680 for a description and a link to GBIF, showing it to be a Mediterranean – south Atlantic species reaching north to Brittany, so quite likely in SW Britain. I would have overlooked fertile material as Ramalina fastigiata. Time to get checking with K!

Neil
Neil Sanderson
JennyS
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Re: Ramalina with medulla K+ pink-red

Post by JennyS »

Success!
Four more specimens from a twig and a small branch all with medulla K+ very slowly pink-red and the last was fertile (plus a bonus Tremella).
There seems to be quite a variation in thallus shape with some more reminiscent of R. canariensis than R. fastigiata.

zz q Ramalina pusilla 2 231115 012.jpg
zz q Ramalina pusilla 2 231115 012.jpg (87.88 KiB) Viewed 773 times
zz q Ramalina pusilla 2,3 231115 019.jpg
zz q Ramalina pusilla 2,3 231115 019.jpg (101.72 KiB) Viewed 773 times
zz q Ramalina pusilla 4 231115 028.jpg
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zz q Ramalina pusilla 5 231115 024.jpg
zz q Ramalina pusilla 5 231115 024.jpg (62.19 KiB) Viewed 773 times
zz Tremella 231115 046-2 Ram pus5.jpg
zz Tremella 231115 046-2 Ram pus5.jpg (66.32 KiB) Viewed 773 times
Jenny Seawright
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Re: Ramalina with medulla K+ pink-red

Post by GERAULT »

All our congratulations Jenny for this perseverance crowned with success.

Alain
JennyS
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Re: Ramalina with medulla K+ pink-red

Post by JennyS »

Thanks Alain, and I found some more fertile thalli on a thinner twig that would possibly have received more sunlight, images below. There's at least one mature apothecia so I'll check that for spore size.

There seems to be a K+ reaction from the cortex as well as the medulla, though the medulla reaction is K+ pink-red rather than the cortex reaction which dries a browner red. Definitely slow though, one specimen took 5 minutes to react, another took 15 minutes!

w q Ramalina pusilla 7 231116 045.jpg
w q Ramalina pusilla 8 231116 039.jpg
w q Ramalina pusilla 10 231116 005.jpg
Jenny Seawright
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Re: Ramalina with medulla K+ pink-red

Post by GERAULT »

Quite typical Jenny.

Alain
JennyS
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Re: Ramalina with medulla K+ pink-red

Post by JennyS »

Thanks Alain - and the spores from specimen in the last photo (section in K) were 1-septate 10-12(-15) x 4-5(-6) µm

z Ramalina pusilla 10 231116 spores.jpg
z Ramalina pusilla 10 231116 spores.jpg (78.72 KiB) Viewed 734 times
Jenny Seawright
Glos lichens
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Re: Ramalina with medulla K+ pink-red

Post by Glos lichens »

Maybe that accounts for all the grotty Ramalina "fastigiata" I see. This K+ red specimen from a perfectly ordinary roadside tree trunk in Gloucestershire, miles from any maritime influence, that I shoved in my pocket when out bird-watching yesterday for no other reason that I had been interested to read this thread.
Attachments
20231121_190644_190643719T.jpg
Glos lichens
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Re: Ramalina with medulla K+ pink-red

Post by Glos lichens »

The plot thickens. I collected five specimens from an Almond tree in a garden - exposed but not coastal - and every last one of them is K+ red, usually quite fast. It is important not to put too much K on (which just swamps it). A little smudge using a brush produces a K+ red reaction usually evident within a minute, but it can be patchy. Here are photos from one of the specimens.
The spore size was usually about 13 microns, single septate, but not as curved as Jenny's. Thus the spores are at the upper end for Ramalina pusilla and the lower end of the range for R fastigiata given on the Italics website. I can't see the blackened parts mentioned as one of the diagnostic features in the key for pusilla.
Something different hiding in plain sight, like Lecanora hybocarpa?
Juliet
Attachments
habit and mm scale
habit and mm scale
dab of K affecting medulla and at least showing through fenestrate cortex
dab of K affecting medulla and at least showing through fenestrate cortex
K+ red piece of thallus
K+ red piece of thallus
hymenium squash, k-ink-vinegar stain, micron scale
hymenium squash, k-ink-vinegar stain, micron scale
spore, k-ink-vinegar stain, micron scale
spore, k-ink-vinegar stain, micron scale
JennyS
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Re: Ramalina with medulla K+ pink-red

Post by JennyS »

Hi Juliet,
I'm glad you also found multiple Ramalina's with a K+ red reaction (and reassured that my K+ red wasn't just a localised anomaly) but unfortunately Paul Cannon thought none of the specimens I sent him were Ramalina pusilla. There's definitely something odd going on though!

Below is his reply to me:
Thank you for the specimens, which arrived yesterday afternoon.
I haven't tested all ten of the thalli, but I couldn't get a K reaction at all from the medulla of four of them, and Pd tests were also negative. One however had a few tiny structures visible when I shaved off the cortex with a razor blade which went pinkish with K, but these turned out to be pycnidia. These are only described in the generic account for Ramalina in LGBI2/3, but these ones had no blackening around the ostiole. They aren't mentioned in the Lichens marins description of R. pusilla, but are referred to as black in the ITALIC account. The ascospore measurements I made (in water) were (12.5-) 13.2-15.3 x 5.8-7.1 µm, which fits pretty well with the description of R. fastigiata in LGBI2/3.

So, I'm afraid that none of this really supports an identification as R. pusilla. Possibly the K reaction you got was due to surface contamination of some sort, and I don't really buy into the concept of a "slow" K reaction. It is possible that there are trace amounts of salazinic acid in R. fastigiata that have been overlooked in the past, or occasional chemotypes which haven't been documented.

We would also need to investigate the identity of European collections identified as R. pusilla. It seems that there is some chemical variation at least, and as the species was originally described from the Galapagos islands it seems unlikely to me that any of the European populations belong to the genuine species. It does seem that R. fastigiata is excessively variable in morphological terms, and could harbour cryptic species, but we would need sequences to be sure. So, perhaps not the result you were hoping for, but it was a very useful exercise.
Jenny Seawright
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