Notes: Following the methodology adopted in observation 199685, we apply the key for the genus Graphis presented in Ref. 1 (see also Ref. 2), since the spores react bluish/violet to the addition of melzer.
Taken into account the features of the specimens under consideration (see attached photos), I came to the conclusion that it may belong to Group 3 in that key characterized by:
Group 3: Labia entire, excipulum apically carbonized, hymenium clear, ascospores muriform
Some notes about each choice. It is still difficult for me to separate labia entire vs. striate, but looking to the photos of the specimens and to the microscopic sections I found no trace of striation, thus classified it as “labia entire”. Regarding the carbonization of the exciple, another dificult task in general, it is clear from the photos that no carbonization exists in the basal part of the excipulum. That
there are no lateral carbonization is less obvious, but again the close up of a section in attached photos shows that the lateral carbonization, if existent, is rudimentar. In the graphis sensu lato that I have analise till now this “hymenium clear” is more or less obvious, though in specimens like this it is difficult to visualise an entire ascum in the microscopy. Finally, “ascospores muriform” is a clear feature.
Gowing to the key for Group 3, we have:
1 Ascospores medium-sized to large (45–160 × 15–35 µm); stictic acid (K+ yellow) or
no substances (K-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 No substances (K-). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5(2) Ascospores 6–8 per ascus; lirellae erumpent, with lateral thalline margin, elongate
and irregularly branched (deserpens-morph). . . . . . . . . . . . . . . 6
6(5) Ascospores (small to) medium-sized (25–75 × 13–20 µm); Europe
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Graphis britannica Staiger
All the choice are clear, due to the chemistry observed (K-), the spores measurements (see the photo of the spores), to the number of spores per ascum that, though difficult to observe, one can say for sure that there are more than 4 (see the photo in Melzer), and the morphology of the lirellas, clear from the photos in loco and to the microscopy.
The result obtained also seems plausible, since Graphis britannica is one of the few Graphis spp. known to exist in Europe and, in particular, is know to exist in Great Britain, according to the Bristish Flora. Finally, Graphis britannica should be the current name for Graphina anguina.
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Looking for something else I found three references, given below, that confirm the existence of Graphis britannica in Portugal and, particularly, at this location in the case of the first two :
Jones, Maurice P. – Some information on the distribution of lichens in Portugal; Portugaliae Acta Biol., 20: 121-224 (2002). (Available at:
Jones, Maurice P. – Notes on the distribution and composition of epiphytic lichens communities with Nephroma laevigatum Ach. in Portugal; Portugaliae Acta Biol., sér. B, 18: 51-120 (1999).
Tavares, Carlos N. – Alguns líquenes interessantes da região de Sintra; Bol. Soc. Brot., 16 (2): 203-215 (1942).
Let me also add a note on the taxonomy. It seems that the name for the species under consideration is “puzzling” as one can see from the paper mentioned below, where the name Graphis inustuloides is given to it:
Lücking, Robert & McCune, Bruce – Graphis pergracilis New to North America, and a New Name for Graphis britannica Sensu Staiger auct.; Evansia 29(3):77-84. 2012.
This is the only species I know of the genus Graphis with real muriform spores (i.e., not “biocellate”). It was formely placed in the genus Graphina (as G. anguina). I found it only once, at this location, and intended to revisit the specimens. That was allmost not possible, because the tree were the lived fallen down, but in such a position that the specimens were visible. I took new photos and collected the specimens.
Created: 2015-02-26 17:27:49 CST (-0500)
Last modified: 2015-07-09 12:46:20 CDT (-0400)
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