Observation 316467: Lichen P. Micheli

When: 2018-05-12

Collection location: Matinha de Queluz, Sintra, Portugal [Click for map]

Who: zaca

No specimen available

Growing on a wall made of cement and many pieces of rock, some with big dimensions.

I was not able to find the genus to which these specimens belong, let alone the species. The question is that the microscopy reveals the following features:
(a) Ascospores hyaline, mostly 3-septate (already inside the asci) with average dimensions of 16.4 × 5.2 µm;
(b) paraphyses abruptly swollen at the apices with brown caps;
and I could not find a genus with such features.
According to the Sonoran Flora not many genera have property (a); the best I could find was Lecania, but even in this genus there are not many species with 3-septate spores and, looking at the descriprtions, the two found (L. coeruleorubella and L. cuprea) do not seem to be good candidates.
For the property (b) I have found a strong candidate: Catillaria (or a related genus), which has hyaline spores, simple or 1-septate, but not 3-septate in general.

For convenience regarding the presentation of the microscopy features I labeled those specimens appearing in the first set of photos, taken in loco, which were analyzed under the microscope as Sp. 1, Sp. 2 and so on.

Dimensions of the spores observed in Sp. 1 (measured inside the asci) :
(12.7) 14.8 – 17.7 (20.1) × (4.3) 4.7 – 5.8 (5.9) µm
Q = (2.7) 2.8 – 3.7 (3.8) ; N = 22
Me = 16.4 × 5.2 µm ; Qe = 3.2


Sp. 1
Sp. 2
Sp. 2 – close up
Sp. 3
Chemical reactions of the specimen in the above photo;
Microscopy – Sp. 1: Apothecial section (x100, in water);
Microscopy – Sp. 1: Hymenium (x400, in phloxine);
Microscopy – Sp. 1: Hymenium (x400, in phloxine);
Microscopy – Sp. 1: Hymenium (x400, in phloxine);
Microscopy – Sp. 1: Hymenium (x1000, in phloxine);
Microscopy – Sp. 1: Asci (x1000, in phloxine);
Microscopy – Sp. 1: Asci (x1000, in lugol);
Microscopy – Sp. 2: Apothecial section and its close ups (x100 & x400, in KOH);
Microscopy – Sp. 2: Hymenium (x400, in KOH);
Microscopy – Sp. 2: Hymenium (x400, in KOH);
Microscopy – Sp. 2: Hymenium (x400, in KOH);
Microscopy – Sp. 2: Paraphyses and spores (x1000, in KOH);
Microscopy – Sp. 3: Apothecial section in water and its KOH reaction (x100);
Microscopy – Sp. 3: Apothecial section in water and its KOH reaction – close ups (x400);
Microscopy – Sp. 3: Excipular zones – close ups (x400, in water and in KOH);
Microscopy – Sp. 3: Apothecial section in lactophenol blue (x100) and a close up of a part (x400);
Microscopy – Sp. 3: Part of exciple and paraphyses nearby in lactophenol blue (x1000);
Microscopy – Sp. 3: Asci in lactophenol blue (x1000).

Proposed Names

31% (2)
Recognized by sight
20% (2)
Recognized by sight: see Observation 278239.
Based on microscopic features
-28% (1)
Recognized by sight: just for the record…
28% (1)
Recognized by sight: If on-line photos of T. mesoidea are correct, then it is definitely not that. I would call this T. cf. philippea, but MO doesn’t understand “cf” notation.

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

= Observer’s choice
= Current consensus


Add Comment
Uncooperative species.
By: zaca
2018-09-12 12:21:03 CDT (-0400)

Otherwise it is a good match! :)” AhAhAh!

Yes, very uncooperative of T. philippea
By: Jason Hollinger (jason)
2018-09-12 11:54:49 CDT (-0400)

Otherwise it is a good match! :)

Note that T. philippea has 1-septate spores.
By: zaca
2018-09-12 05:52:39 CDT (-0400)
re: microscope
By: Jason Hollinger (jason)
2018-09-11 16:00:49 CDT (-0400)

I’m sorry, that must be frustrating. Good luck!

Thanks, Jason.
By: zaca
2018-09-11 15:50:17 CDT (-0400)

Sure I will return to this observation. But, I don’t believe in Toninia here.
Unfortunately I continue with problems with the microscope that I don’t see how to solve. The microscopy of this observation was done few after the date of the observation.

Thanks for reminding me to look at the otherobservation
By: Jason Hollinger (jason)
2018-09-11 14:55:46 CDT (-0400)

I would say that these two observations are quite different, personally. The thallus is clearly areolate in this observation, versus granular in the other. The apothecia are black in all of the photos of this observation, versus various pale brownish grayish colors in the other. The apothecia in this observation at least start out with a clearly developed exciple, versus the other is convex and emarginate right from the start. The paraphyses’ tips are strikingly globose and pigmented in this observation, versus inconspicuously swollen and unpigmented in the other. The ascus stain is hard to read in the other observation, but look at the ascus in the lower left of image 12 in the other observation: you can just begin to make out the dark walls of the axial mass starting to stain there. From that photo alone, I couldn’t rule out porpidia- or biatora-type, but it is at least consistent with micarea-type. The stains in image 16 in this observation show the clearest example of bacidia-type I think I’ve ever had the pleasure of seeing. :)

I would still recommend looking at Toninia. Well, actually, I can check it just as easily, given the thoroughness of your observation! Do you have Timdal’s monograph? Try Toninia mesoidea. I’ve never heard of the species, but the range is about right. I was thinking T. phillipea right from the start, but the 3-septate spores rule that out. Assuming the two species looks similar, I’d say T. mesoidea is a good candidate. But I haven’t read through the description, maybe there are still some problems. But if so, I’d suggest that you have a new species related to T. mesoidea at very least.

But obviously, you have an advantage over me, having a specimen in front of you! Just sharing my thoughts and suggestions. I won’t be at all offended if you decide I’m totally wrong! :) God knows it wouldn’t be the first time, haha.

Did you compare with Observation 278239?
By: zaca
2018-09-11 14:28:49 CDT (-0400)

There I see the same type of asci (including tholus) and spores.

Your ascus stains are amazing!
By: Jason Hollinger (jason)
2018-09-11 13:39:02 CDT (-0400)

As always, you set the standard for quality microscopy. :)

But I’d interpret those asci as bacidia-type, and quite confidently. That points to Lecania, I think. Micarea has a particular ascus type with very narrow axial mass which penetrates all the way through, and with walls darker than the rest of the tip. It comes off looking like a really tiny, faint, narrow lecanora-type in my experience. Emphasize tiny. Micarea asci are so small they are hard to see the stain clearly.

I would urge you not to rule out Lecania because you can’t find any good matches in the literature. I think there are many regions in which the Lecania are poorly studied. It is true that 3-septate spores are not the norm, but they definitely do occur in that genus. And Portugal should have a rich representation of the genus, as you are more or less entirely coastal.

Oh, shoot, one additional genus to consider — I always forget! — Toninia. Yes, Toninia. Not all species are squamulose. Honestly, I don’t even know how they decide which genus to put the crustose species in. Toninia and Lecania are virtually identical in those cases. [Oh right, Toninia has lecideine apothecia, Lecania lecanorine apothecia… haha. “Subtle.” :)]

Good luck!

A thorn in my side!
By: zaca
2018-09-11 13:22:42 CDT (-0400)

I never went back to this observation (say I forgot it), but now I have something to add, that at the time I should recall. In fact, the lichen in consideration is nothing but a Micarea and, most probably, M. lignaria. My only doubt refers to the septation of the spores: most of them have 3 septa but seem there are others with more. Unfortunately, this time I didn’t observed isolated mature spores as in Observation 278239. Now the spores are smaller than in such observation, but the range given for the lenght of the spores in the British Flora is very wide : 16-36(-38) µm.

Created: 2018-05-16 13:31:08 CDT (-0400)
Last modified: 2018-09-12 12:21:04 CDT (-0400)
Viewed: 112 times, last viewed: 2019-08-23 05:14:30 CDT (-0400)
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