Observation 166068: Graphidaceae

When: 2014-05-28

Collection location: Braga, Portugal [Click for map]

Who: Elsa (pinknailsgirl)

No specimen available

On oak tree. Suburban.


Proposed Names

29% (1)
Recognized by sight
56% (1)
Recognized by sight: Not sure if the last photo is of the same species than the others, the apothecia seeming more stellate rather than branched lirellas.

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= Observer’s choice
= Current consensus


Add Comment
Differences between two species.
By: zaca
2014-06-03 18:05:09 UTC (+0000)

The (full) paper referenced below came to my hands (before I had access to the 1st page only). Regarding the comments by Elsa about the differences betwen the two species P. dendritica and P. smithii, I quote from that paper:
- From the introduction:
“Given the difficulty to differentiate P. dendritica and P. smithii while studying the material from the Iberian peninsula and the diversity points of view …(several citations)… it was thought necessary to undertake a taxonomical study of P. smithii, based on the analysis of type material.”
- After the discription of the species, the following note is given:
“Observ.: In the Iberian Peninsula P. smithii does not have morphological, anatomic, chemical or ecological characters for a clear fifferentiation from P. dendritica (see discussion).”
- In the discussion, after the statement of the differences found between the two species, the following conclusion:
“In our opinion, morphological, anatomic, chemical or ecological characters are not clear enough to separate these two species; material from outside the Iberian Peninsula has been studied as well, with the same results.”

As always we have to take some care in using these results. I found in the same paper maps with the distribution of the four species of Phaeographis existing here, which clearly are far from being complete. For instance, in the given distribution of P. dendritica, stated several times in the paper to be the most common of the species here, only one point appear in Portugal (corresponding to the region Mafra-Sintra). Certainly this is not true, since I found it in several places. This is maybe caused by the few written reports from our country that could be cited.

M.E. López de Silanes and J. Álvarez, The genus Phaeographis Mull. Arg. (Graphidaceae, Ascomycotina) in the Iberian Peninsula, Nova Hedwigia 77(1-2): 147-160, 2003.

What I meant
By: Elsa (pinknailsgirl)
2014-05-29 09:04:38 UTC (+0000)

is that, looking for the photos available on internet, I see quite well the differences, maybe because they are chosen to show that. But if we can observe some details like exciple and so on, maybe it would be macroscopically identificable or… we can do like in Irish lichens, we can put “Identification needs confirming with microscopy”.

About P. smithii, more as seen on pictures, I read “Phaeographis smithii qui diffère par ses lirelles un peu plus courtes et plus creuses”, so, there is a macro distintion. http://www.lichensmaritimes.org/...

About exciple, I understand it in fungi, here, I do not know to recognize it, which is the apothecia here? Do I have to wound the tree to observe it?

Not so easy …
By: zaca
2014-05-29 00:33:25 UTC (+0000)

The identification of lirellate lichens is not so simple as you mentioned; some species can present great variations in appearance, some of which I believe are much related with the host; sometimes the lirellas are more closed or more open, are more or less carbonized, have or not a raised thalline margin; are closed or opened below the hypothecium, and so on …

By the way, I never heard that P. dendritica is very different from P. smithii.

Concerning your question on terminology, having the British Flora with me, I gave you the terms in its glossary:
Exciple – tissue forming the margins or walls of an ascoma;
Thalline exciple – the margin of an apothecium which contains photobiont as well as fungal cells; usually of the same colour and consistency of the thallus.

So, exciple with margins closed means that in section you have almost a ring, only a small part is missing; the inside is like a tube.

I agree
By: Elsa (pinknailsgirl)
2014-05-28 23:59:37 UTC (+0000)

the last photo could be another, I believe, Phaeographis (if P. dendritica it could also stellate, right?). BTW what does exciple with margins closed really means? What is an exciple?

And… why do we need more tests, if the lirella is so different from P. dendritica to the others (P. smithii, lyellii or inusta)?

By: Elsa (pinknailsgirl)
2014-05-28 19:30:35 UTC (+0000)

Please translate :)

Created: 2014-05-28 19:29:22 UTC (+0000)
Last modified: 2014-05-30 00:06:46 UTC (+0000)
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