Observation 206108: Ochrolechia parella (L.) A. Massal.
When: 2015-06-06
Who: zaca
No herbarium specimen

Notes: Growing on bark of Fraxinus.

Images

526347
526348
526349
Chemical reactions (made in loco).
526668
Microscopy: Sections;
526669
Microscopy: Spores.
526897
Chemical reactions – Dried material.

Proposed Names

29% (1)
Recognized by sight
58% (1)
Eyes3
Used references: Irwin M. Brodo, Studies in the lichen genus Ochrolechia. 2. Corticolous species of North America, Canadian Journal of Botany 69:733-772, 1991.
British Flora: Smith et al. (eds.), The Lichens of Great Briatain and Ireland, The British Lichen Society, 2nd ed., 2009.
AFL Lichen: http://www.afl-lichenologie.fr/...
Lichens Marins: http://www.lichensmaritimes.org/...
Based on microscopic features
Based on chemical features

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

Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

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Very interesting analysis!
By: Jason Hollinger (jason)
2015-06-11 16:04:00 CDT (-0400)

Very persuasive. I’m particularly interested in Nimis’s comment. Portugal must be an amazing lichen habitat. (Well, based on your photos, that was already obvious, but that’s excellent confirmation of your already excellent observations. :) Much to think about. Thanks for sharing!

New try.
By: zaca
2015-06-11 15:44:18 CDT (-0400)

Having received the paper of E. Brodo (see references) that Jason kindly sent me, I noticed that there some comments are made comparing N. A. species with European ones and, moreover, at the end some excluded taxa are also briefly mentioned. Therefore, I made the following exercise: To apply Brodo’s key to my material and see if the result lead to a species that (at least vaguely) resembles an european one. I also intended to apply the key in the British Flora to my specimen.
To these purposes, I start by repeating the chemical reactions (see the corresponding photo, already attached to this observation). Here is what I conclude from there:
Thallus: C+ pale yellow, K-, KC+ yellowish (in fact, it seems KC- but close to the apothecia one can see yellow)
Apothecial disc: C+ red (C+ yellow at the margin), K- (or K+ undefined), KC+ red.

With these data, I performed the following evolution in Brodo’s key:
1 → 11 —> 21 —> 23
At this point, there are two options:
Algal layer thick, conspicous below the hypothecium, … —> O. pseudopallescens
Algal layer scantly or absent below the hypothecium, … —> leads to a group of N. A. species with no relation to european ones
Note that O. pseudopallescens is also a N. A., a new species described in that paper, and Brodo says: "Although O. pseudopallescens maybe the most common corticolous Ochrolechia in North America, it remained hidden under the collective name “O. pallescens” for a century. It was included within O. parella …" (I omit the rest, but the connection with O. parella was done). It is also curious to note that the confusion of the names “O. pallescens” and “O. parella” seems to remains unsolved after all these years. The British Flora doesn’t mention the former, while other sites, like AFL Lichens (Association Française de Lichénologie), consider them as diferent species (the former with C+ red discs, the latter with C+ yellow discs); yet another site, Lichens Marin (Lichenes maritimi Armoricae), consider two subspecies of O. pallescens: subsp. parella and subsp. pallescens, the latter with a form differing from the canonical type by its habitat, pieces of wood: wooden ship wrecks, poles and fences.
From the British Flora, I arrive to O. parella (some authors consider this species as only saxicolous, but the Bristish Flora says “on rock, rarely bark”). In this respect, I’m each day more inclined to accept without restrictions a comment that Prof. P.L. Nimis (a well known Italian lichenologist) once made to a portuguese student (presently also a lichenologist) that found a usually saxicolous species on a tree, more or less as follows: “Lichens in Portugal can live more or less in every substrata, because they have the necessary sun and humidity conditions for their development”.
Therefore, I have no alternative to O. parella and this is the name that I propose to this specimen.

But … this specimen lived on bark!
By: zaca
2015-06-10 11:32:12 CDT (-0400)

[EDITED] Ignore, since I didn’t saw last comment.

My apologies…
By: Jason Hollinger (jason)
2015-06-10 11:29:19 CDT (-0400)

When I saw you mention O. parella, zaca, I assumed this was growing on rock! :) I’ll send you Brodo’s excellent paper covering corticolous species in North America. It’ll give you a couple new characters to pay attention to, if nothing else. (Like whether there is algae under the apothecia, and whether the proper margin is prominent as a second, pinkish, inner ring.)

Species of Ochrolechia on rock are poorly understood
By: Jason Hollinger (jason)
2015-06-10 11:26:14 CDT (-0400)

At least in North America, there are good treatments of the ones on bark, both fertile and sorediate, but not for ones on rock.

The Sonoran Flora, for example, just calls most specimens “O. aff. parella” and leaves it at that. Sounds like you’re in a very similar situation. They do, however, split off O. splendens, an inland species with lichexanthone (UV+ yellow) and C+ pink/red cortex and apothecial disk. And they mention something called O. peruensis which lacks lichexanthone and has C+ red medulla and cortex.

The Ozarks flora includes O. trochophora, with C+ pink/red cortex but C- medulla.

The British and Swedish Floras both additionally include O. tartarea, also C+ pink/red.

I can’t find any other mention of saxicolous species in my literature.

Summary: (nonsorediate, nonisidiate species only)

O. parella – UV-, C±y
O. splendens – UV+y, C+r
O. peruensis – UV-, C+r
O. tartarea – UV-, C+r
O. trochophora – UV-, C+r

Don’t ask me how to distinguish the last three! They each appear in a separate paper, without comparisons with each other… But clearly, none apply to this specimen, because it’s not C+r.

… In other words: “what zaca said!”

I see no other option …
By: zaca
2015-06-10 06:23:43 CDT (-0400)

but the omnipresent O. parella. This species is so common and variable either in shape or in chemical reactions (rarely it presents the chemistry given e.g. in the British Flora) that sometimes make me doubt about the existence of other species. As you know our checklist is a “dreamm”, thus you will never know if …

What prevents
By: J-Dar
2015-06-09 22:41:13 CDT (-0400)

identification to species level?

Microscopy added.
By: zaca
2015-06-09 20:03:32 CDT (-0400)

Spores:
(52.7) 60 – 69.2 (73.3) x (27.9) 30.5 – 37.1 (40.2) µm
Q = (1.6) 1.7 – 2.1 (2.4) ; N = 18
Me = 64.6 × 33.3 µm ; Qe = 2

Paradox?
By: zaca
2015-06-08 12:32:25 CDT (-0400)

I’m giving my best, but that is the paradox in solving mysteries: the effort made to solve one provides several others to be solved.

Keep using whichever acids you’re using!
By: Jason Hollinger (jason)
2015-06-08 12:17:47 CDT (-0400)

Thanks for looking that up. At this rate there will be no mysteries left… by next millennium.

“in loco” vs. “in situ”
By: zaca
2015-06-08 12:05:22 CDT (-0400)

After your remark I doubt about which Latin expression is more common and it seem that its depends where you live. At the portuguese address
http://www.ciberduvidas.com/pergunta.php?id=13916
you can see in my mother tongue, the following question and correspondent answer by the expert,
Question:
The Latin phrases “in situ” and “in loco” may be used indiscriminately or have different meanings and uses? If not, can you give some examples?
Answer:
The Latin expressions in situ (“in place”) and ‘in loco’ (‘on-site’) are semantically equivalent and therefore can be used indiscriminately. It seems, however, that the use of “in loco” is more vulgarized and its meaning is likely to more easily understood by the general public.

Therefore, I’ll continue to use “in loco”, while dropping acid, and perhaps you will reply “in situ”, that the acids are out of date…

I love the term “in loco”!
By: Jason Hollinger (jason)
2015-06-08 11:30:27 CDT (-0400)

Does it mean “while dropping acid” in Latin? ;) Much more suggestive and colorful than the bland “in situ”!

Nice study of Pertusaria and Ochrolechia!

Created: 2015-06-08 10:49:58 CDT (-0400)
Last modified: 2015-06-11 15:46:19 CDT (-0400)
Viewed: 110 times, last viewed: 2016-10-25 08:56:20 CDT (-0400)
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