When: 2017-06-03

Collection location: Serra de São Mamede, Portugal [Click for map]

Who: zaca

No specimen available

Notes:
The best I can say is that I’m confused by so many similar Buellia.
Referring only to the material of this observation (because there are others), these specimens immediately reminded me of others obseerved about 5 km south (observation 242279), classified as B. subdisciformis, this time growing on a vertical wall in a granite outcrop.. Noticing differences in appearance none, only the chemical reactions are slightly different, namely the bleach test: C + weak red; Keeping K+ yellow to red and KC+ red. In spite of being weak, the C reaction is clearly visible and I’m experienced in seeing similar coloured reaction in Diploschistes (for instance) where strong C+ red would be expected.
Consulting the references available, I become aware of B. saxorum with a characteristic C + red reaction on thallus, but with K+ yellow and not K+ yellow to red. No other clear distinction is made between the two above mentioned species; Of couse there are (variable) coloration of the thallus: more withish in B. subdisciformis and more yellowish in B. saxorum.
Looking for more information, one of my frequently used websites:
http://www.lichensmaritimes.org/...
reports the two species. At the page devoted to B. saxorum there are 8 photos with specimens, two of which illustrating the chemical reactions. In the second photo with the chemistry (the fourth in the sequence) the chemical reaction are a perfect replica of what I got (please, compare!). Thus, I’m going towards B. saxorum, but …
Let me also say something on the poor microscopy presented; The scarse material colectted by scraching the rock is in bad conditions to make clear sections of the apothecia, for instance, but the features are more or less illustrated. Let me also remark the existence of some spores bigger and wider than the vast majority, with dimensions exceeding those of any of the above mentioned species (which have very similar, not to say equal, in the references).

Images

Sp. 1;
Sp. 2;
Sp. 3;
Sp. 3 – Chemical reactions;
The wall showing the previous three specimens among other lichens;
Sp. 4;
Microscopy: Apothecial section (x100, in water);
Microscopy: Apothecial section in water and its KOH reaction (x100);
Microscopy: Hymenium views (x400, in KOH);
Microscopy: Asci (x1000, in KOH);
Microscopy: Asci and spores (x1000, in KOH).

Proposed Names

58% (1)
Used references: 1) British Flora; 2) Lichens maritimes: http://www.lichensmaritimes.org/index.php?lang=en
Based on microscopic features
Based on chemical features

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= Observer’s choice
= Current consensus

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Created: 2017-06-08 04:10:34 PDT (-0700)
Last modified: 2017-06-08 04:11:12 PDT (-0700)
Viewed: 28 times, last viewed: 2019-08-13 04:03:54 PDT (-0700)
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