Observation 163951: Phaeographis Müll. Arg.
When: 2014-03-23
Who: zaca
No herbarium specimen

Notes: The form of the lirellae points more to Phaeographis than to Graphis but the dimensions of the spores (Average dimensions: Me = 48.7 × 8.8 um ; Qe = 5.4 (N=12))are incompatible with the former genus.

Images

416520
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Chemical reactions;
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Microscopy 1:
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Microscopy 2;
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Microscopy 3;
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Microscopy 4.

Proposed Names

19% (2)
Eye3
Based on microscopic features
31% (2)
Eyes3
Based on microscopic features: brownish spores (see comment)

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

Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

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Confusing!
By: zaca
2014-05-01 16:34:10 CDT (-0400)

I’m a little disappointed, because I thought you had noticed the change in my avatar: YES, I found “the one” species.
Now about your first recent comment: Please look at the diagram in Figure 43 (p. 692) of the British Flora, which shows precisely that P. dendritica has a black (carbon) layer at the bottom of the hymenium, contrary to what happens in P. smithii.

My thanks for your comments, Jason, who are always enriching.

We may be making progress…
By: Jason Hollinger (jason)
2014-05-01 16:28:01 CDT (-0400)

The general habit photo in Schumm page looks off, but Bruce Ryan makes specific note about the variability of the overall appearance of the apothecia. Microscopically it looks very promising.

(Sorry we got our comments out of order again, I’ve got to report that as a “bug” in Mushroom Observer — there’s got to be some way to warn the user that someone else has posted a comment in between the user starting their comment and going to post it…)

Good points, as always
By: Jason Hollinger (jason)
2014-05-01 16:12:53 CDT (-0400)

I just learned about another genus superficially similar to this, Leiorreuma. Look at L. sericea in particular. The spores may be a better match… okay, no, still too short: 16-21 × 5-8 µm. The exciple is fully carbonized. (Notice the dark brown/black layer below the hymenium — that, too, may rule out Phaeographis, at least in North America.)

I’m still convinced these are “brown” spores in the Graphidaceae sense. I just tried another informal source for North America (Bruce Ryan’s working keys for Phaeographis in the old sense of brown-spored Graphis), and it suggests Phaeographis dendritica… but then other sources say it has a non-carbonized exciple. At least its spores were the right size: 30-50 × 7-9.5 µm.

Wrong supposition and new reference.
By: zaca
2014-05-01 16:00:41 CDT (-0400)

I´m affraid that my previous supposition that Phaeographis spp. cannot have so big spores is wrong. First I looked again to the British Flora, where the spores dimensions for P. dendritica are (26-)30-40(45-) x 6-9 um. Then I saw the in the webpage of Felix Schumnm the dimensions of the spores for the same species based on material from Azores (Portugal), yielding 30-50 × 7-9,5 µm (see
http://fschumm.bplaced.net/...). This means that we are very close to the dimensions of the spores given for the specimen in this observation and, consequently, the genus Phaeographis cannot be excluded.

Phaeographis in the Iberian Peninsula.
By: zaca
2014-04-30 18:00:50 CDT (-0400)

Here is something that support my criticism about this being a Phaeographis sp.. I had only acccess to the first page of the following paper that states that only four corticolous_Phaeographis spp._ were known (it as written about ten years ago):P. dendritica, P.inusta, P. lyellii and P. smithii. The 1st and the 4th we already knew that couldn’t be, due to the spores dimensions. The other two can also be excluded on the same basis, since the 2nd has spores 16-25 um long and the 3rd has spores 24-35 um long, according to the site http://www.habitas.org.uk/lichenireland/

Ref.:
López de Silanes, M.E.; Álvarez, J.;
The genus Phaeographis Müll. Arg. (Graphidaceae, Ascomycotina) in the Iberian Peninsula;
Nova Hedwigia, Volume 77, Numbers 1-2, 1 August 2003 , pp. 147-160(14).

I don’t think that’s surprising
By: Jason Hollinger (jason)
2014-04-23 20:23:49 CDT (-0400)

The Graphidaceae are not so well known as the usual apothecioid crusts. They tend to be more tropical. (The photobiont is Trentepohlia which prefers warmer climates.) So it makes sense the British Flora would only have a few. By contrast, there are dozens of each in the checklist for a single little swamp in southern Florida (Fakahatchee Strand).

There are also additional genera to consider. These are the genera covered in the “Revised Keys to the Graphidaceae in southeastern North America”, an informal document distributed by J. Lendemer for a lichen workshop in 2008:

Acanthothecis — spores hyaline, paraphyses tips ornamented, exciple not carbonized
Carbacanthographis — spores hyaline, paraphyses tips ornamented, exciple carbonized
Diorgyma — spores hyaline, thallus thick and poorly corticate
Dyplolabia — densely white pruinose, strongly C+ red
Fissurina — spores hyaline, lirellae noncarbonized and immersed
Glyphis — apothecia cup-shaped or in raised clustered “pseudostroma”
Graphis — spores hyaline, exciple at least partly carbonized
Leiorreuma — spores brown, exciple fully carbonized
Platythecium — spores hyaline, exciple noncarbonized and sessile
Platygramme — spores brown, exciple carbonized strongly at apex
Phaeographis — spores brown, exciple weakly carbonized laterally
Sarcographa — spores brown, apothecia clustered
Thalloloma — spores hyaline, exciple noncarbonized and sessile, labia poorly developed
Thecaria — spores brown, apothecia cup-shaped or clustered

It’s a daunting field at the beginning. There are useful gestalt characters for most genera — as you noted, yours looks more like a Phaeographis than a Graphis — but it takes some time to develop that instinct, I guess. I still struggle with what “ornamented paraphyses” and “brown spores” really mean sometimes. It’s a difficult group. And be warned: thin whitish crusts like these with Trentepohlia photobiont very often give extremely convincing false K+ orange, red or brown reactions. That’s fooled me many times. And I’ve also had other workers complain about reported spore lengths being notoriously inaccurate. It’s a mess!

Good luck!

Perhaps …
By: zaca
2014-04-23 18:10:36 CDT (-0400)

I´m in trouble again with the bibliography. Firstly in the portuguese checklist no Graphis or Phaeographis appear; Secondly, for the four species of Phaeographis considered in the British Flora, the maximum lenght of the spores is 40 µm (P. dendritica, that however can have some up to 45 µm); The average lenght of the spores observed in this specimen was 48.7 µm as I wrote in the Notes. So, maybe there exists here a species of Phaeographis with longer spores: Who knows?

Spore size is not (no longer?) a good way to distinguish Graphis from Phaeographis
By: Jason Hollinger (jason)
2014-04-23 17:23:56 CDT (-0400)

I’m still learning the genera of Graphidaceae, and I certainly don’t understand the history of the changes in the genera.

But the latest info I have (for eastern North America, which has lots of species in both Graphis and Phaeographis) suggests that spore color is more important. Graphis has hyaline spores, Phaeographis brown. And in my experience (some, like P. inusta are abundant in places, so I’ve seen a lot), when they say “brown” they mean “barely tinted brown”. The most reliable way to see the color seems to be in post-mature spores which sort of shrivel up in the ascus and turn dark. Yours could well qualify as brown.

There is a fair global key to Graphis s. str., but I can’t find anything (in my pile of papers) for Europe for Graphidaceae in general or Phaeographis in particular.

Created: 2014-04-23 15:48:18 CDT (-0400)
Last modified: 2014-05-01 16:00:54 CDT (-0400)
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