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Observation 97159: Pertusaria DC.

When: 2012-06-09

Collection location: Estádio Nacional, Oeiras, Portugal [Click for map]

Who: zaca

No specimen available

Specimens growing on bark.
Once again the keys available for the genus Pertusaria did not produce anything acceptable.


Close up.
Chemical reactions on thallus;
Microscopy – Low magnification (Last photo with IKI reaction)
Microscopy – Asci 1;
Microscopy – Asci 2;
Microscopy – spores isolated;
Sp.3 – Close up.
Sp.2 – Close up;

Proposed Names

48% (2)
Based on microscopic features
Based on chemical features
28% (1)
Recognized by sight: see comments

Please login to propose your own names and vote on existing names.

= Observer’s choice
= Current consensus


Add Comment
I agree with your comments,
By: zaca
2012-06-12 13:23:36 MST (-0700)

except that I would say that it has 2 spores/ascus. In fact, every (complete)ascus I saw has 2 spores and I saw plenty of them.

Trying again, on bark this time…
By: Jason Hollinger (jason)
2012-06-12 13:10:36 MST (-0700)

It comes out as a variant of Pertuaria pertusa in both Sipman’s European key and the British Flora. Since this is such a variable taxon, I guess I would tentatively give it that name, despite the odd chemistry. Too bad we don’t have “cf.” notation on MO. :)

(The world key is just a mess. Without TLC, it’s worthless. And it can’t handle chemical variants at all. An abysmal failure.)

No help
By: Jason Hollinger (jason)
2012-06-12 12:52:51 MST (-0700)

I checked the worldwide key, the Europe key (as did you), as well as the British Flora. All three keys clearly do not include your specimen, in my opinion. We agree that it is K- C- KC-, right? I would further say that yours has 1-2 spores per ascus (although you know my reservations about this character), and that they are smooth (I tried rough, too) and hyaline. In none of the three keys did I
ever get to the point of requiring dimensions.

[Oh hell, I just realized this is on bark, not wood! I have to recheck them all… :( ]

Does British Flora give any help?
By: zaca
2012-06-12 12:35:21 MST (-0700)

I just realize that I forgot to mention the dimension of the spores. Here they are:
69.5 [88.7 ; 96.2] 115.3 × 23.6 [32.3 ; 35.7] 44.4 µm
Q = 2 [2.6 ; 2.9] 3.5 ; N = 37 ; C = 95%
Me = 92.4 × 34 µm ; Qe = 2.8
There is a species with 2 spores/ascus with very similar dimensions of spores – Pertusaria dispar – but I didn’t found any picture of it. Moreover, maybe it exists in my country, because there is a publication going back to 1918 of J. Steiner, which is mentioned in the publications of the portuguese checklist.

I take it back…
By: Jason Hollinger (jason)
2012-06-12 11:48:57 MST (-0700)

Pertusaria is the most likely genus to have screwy chemistry. Unbelievable. What an insane genus. We need to get you a UV light and some PD. :)