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When: 2016-03-20

Collection location: Parque de Monsanto, Lisboa, Portugal [Click for map]

Who: zaca

No specimen available

Growing on decorticated wood of a living tree.


Microscopy: Alga and hymenium in lugol;
Microscopy: Apothecial sections;
Microscopy: Hymenium;
Microscopy: Hymenium and spores;
Microscopy: Asci and spores;
Microscopy: Hymenium in lugol;
Microscopy: A small button under the scope.

Proposed Names

29% (1)
Recognized by sight
87% (1)
Used references: Lluís A. FIOL, Líquens epífits de I’area urbanade Palma de Mallorca, SHNB, 1995;
Based on microscopic features

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= Observer’s choice
= Current consensus


Add Comment
Once and again, completely unexpected.
By: zaca
2016-03-22 09:09:17 PDT (-0700)

Thanks, Jason.

Wow, that’s the last thing I would have guessed
By: Jason Hollinger (jason)
2016-03-22 09:00:35 PDT (-0700)

thought for sure it would be something in the Lecanora saligna group. Good work!

Microscopy added. Schismatomma is possible?
By: zaca
2016-03-22 05:54:03 PDT (-0700)

When observed in the field looks like a greyish crust. Magnifying the photo with the camera one can see that is a “regular” lichen with small apothecia (say a “mini lecanora”, though the apothecia have sizes less than 0.5 mm) infected by other fungus with conspicously small black dots.
At home, while looking at the asci and spores of this specimen I had the feeling of “deja vu”. In fact, they are perfect replicas of those already observed in Schismatomma graphidiodes, though smaller (see, for instance, observation 208916 and observation 215224). Now, I got the following dimensions for the spores:
(21.6) 23 – 26.7 (27.9) × (4.1) 4.6 – 5.7 (6) µm
Q = (4.2) 4.4 – 5.3 (5.9) ; N = 32
Me = 24.8 × 5.1 µm ; Qe = 4.8.
As can be seen the spores are consistently 3-septate and have a small range for their lenght, as in the case of the above cited observations.
On the other hand, the small black dots spread by all the thallus are indeed buttons of apothecia. I smash one and inside the button one can see, by transparency, asci and spores (many of them shrived).
Summarizing, the macro features of this specimen are very different from those of S. graphidioides, but the microscopy is similar. I’ve tryed without any success to find a species in Schismatomma with these features. The closer I could find was the species S. ricasolii, which is a synonym of S. graphidioides, whose overall appearance is vaguely similar to my specimen but the apothecia are more irregular and not rounded as in my case. Of course, it may belong to another genus, that I didn’t consider.