Observation 130207: Punctelia stictica (Duby) Krog
When: 2013-02-16
Who: zaca
No herbarium specimen

Notes: Growing on rock.

Images

315706
315707
315708
315709
315710
315711
Chemical reactions.
414596
2014-03-15 Revisited;
414597
2014-03-15 Revisited;
414598
2014-03-15 Revisited;

Proposed Names

-28% (1)
Recognized by sight
28% (1)
Recognized by sight
56% (1)
Eyes3
Recognized by sight: why not? I’ve proposed every other name in the book already!!

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

Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

Add Comment
Hi Jason,
By: zaca
2014-04-23 13:12:02 PDT (-0700)

Sorry about the confusion, but that was my fault, because I didn´t understood well your comments about this specimen at the time I observed it for the first time.
It seems that P. stictica exists in the Iberian Peninsula. At least that species is included in a paper of revision of the species of Punctelia existing here, of which I have access to the first page only:
The Lichenologist 36(5): 299–308 (2004)
Can you send me this paper?
Thanks and best regards,
zaca

Confusing string of comments!
By: Jason Hollinger (jason)
2014-04-23 12:45:47 PDT (-0700)

Sorry about that! I still can’t find a good account of the differences between P. borreri and P. stictica (aside from the former being primarily corticolous, and the latter saxicolous). The Sonoran Flora has this to say (in the key):

5. Thallus margins distinctly brown, usually in a broad band; pseudocyphellae laminal and marginal, irregularly shaped, partly linear; on rocks . . . P. stictica

5. Thallus margins uniformly gray, except sometimes for a thin dark margin; pseudocyphellae laminal, rounded, varying in size rather than shape; on bark . . . P. borreri

Revisited!
By: zaca
2014-04-11 15:50:17 PDT (-0700)

At the time that Jason proposed Punctelia borreri for this specimen I was a bit surprised, mainly because I was not used to observe Punctelia spp. growing on rock. Passing through the place of this observation, I take new photos and confirm the remaing characteristics of that species, namely, that the underside is black with also black rhizines, that are absent at the extreme of the marginal lobes, and that the soralia gives a C+ pink reaction. I attach the corresponding photos.

Because I’d failed to find any record
By: Jason Hollinger (jason)
2013-03-22 16:46:45 PDT (-0700)

But that was before your second comment, where you did find records nearby at least. I can’t figure out what the critical difference between P. stictica and P. borreri is. It looks like P. stictica is relatively smaller, has more sharply-raised conspicuous pseudocyphellae, brown near margin. But it might be the case that material of P. borreri on rock is also smaller and more browned than typical epiphytic material… Tricky. You’d definitely have to take some care with this before reporting P. stictica new for Portugal! :)

RE: “Yeah, looks like P. stictica is out”
By: zaca
2013-03-22 16:31:33 PDT (-0700)

Why is P. stictica out? You didn’t mentioned it in your comment.

Yeah, looks like P. stictica is out
By: Jason Hollinger (jason)
2013-03-22 16:18:14 PDT (-0700)

As is P. subrudecta (C reaction too weak?). Leaves P. borreri. But note that [Longán, A., M.Barbero and A. Gómez-Bolea. 2000. Comparative studies on Punctelia borreri, P. perreticulata, and P. subrudecta (Parmeliaceae, lichenized Ascomycotina) from the Iberian Peninsula. Mycotaxon 74(2): 367-378.] reports lecanoric (strong C+ red) from all specimens(!)

I could be wrong! It just looks strange for Hypotrachyna.

Yeah, looks like P. stictica is out
By: Jason Hollinger (jason)
2013-03-22 16:17:23 PDT (-0700)

As is P. subrudecta (C reaction too weak?). Leaves P. borreri. But note that [Longán, A., M.Barbero and A. Gómez-Bolea. 2000. Comparative studies on Punctelia borreri, P. perreticulata, and P. subrudecta (Parmeliaceae, lichenized Ascomycotina) from the Iberian Peninsula. Mycotaxon 74(2): 367-378.] reports lecanoric (strong C+ red) from all specimens(!)

I could be wrong! It just looks strange for Hypotrachyna.

Just saw …
By: zaca
2013-03-22 16:11:25 PDT (-0700)

that Punctelia stictica appears in the checklist for the portuguese archipelago of Madeira (link) and is also mentioned in the book by Felix Schumm entitled “Flechten Madeiras, der Kanaren und Azoren, 2008”, at least in the key for the genus Punctelia.

Very well observed, Jason.
By: zaca
2013-03-22 15:45:04 PDT (-0700)

For some reason (now I understand that was mainly because I didn’t find any saxicolous species of Punctelia) I put this genus apart. Even having found another specimen of Punctelia nearby living on rock, posted at observation 130261. I also interpreted wrongly the chemistry, and associated the C+ pink/red reaction to a medulla reaction through a broken thallus.
You are right, it must be a Punctelia. Which one? The species you mentioned, P. stictica, seems promising, but I didn’t found any trace of it here.
Thanks, Jason, for putting the things in the right place.

This doesn’t look like Hypotrachyna to me
By: Jason Hollinger (jason)
2013-03-22 11:38:34 PDT (-0700)

Granted, I’m not familiar with all the British species… But the rhizines are wrong, and the shape of the lobes isn’t quite right. We call them “loop” lichens because of distinctive loop-like shape of the axils between lobes, and that’s missing here. The rhizines look too uniformly short and simple (although, yes, in rare cases there are species or abnormal specimens with entirely simple rhizines). The other thing is the color and texture of the surface. It’s hardly conspicuous, but I’d say this is trying to have punctate pseudocyphellae. Lastly, these soralia, while maybe you can interpret them as somewhat erumpent, don’t originate on swellings, so I don’t think they can be called pustulose.

Anyway, that’s my reasoning. I suspect one of the small saxicolous Punctelia instead. There’s P. stictica (C+ weak pink) and P. punctilla (C+ stronger red) in North America. These tend to have a browned uneven coloration (from sun exposure I guess) just like you see in your specimen. They are both black underneath like this.

Created: 2013-03-14 17:33:42 PDT (-0700)
Last modified: 2014-04-23 12:39:53 PDT (-0700)
Viewed: 75 times, last viewed: 2016-09-01 04:52:44 PDT (-0700)
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