Observation 78135: Xanthoparmelia (Vain.) Hale

When: 2011-09-24

Collection location: Serra de São Mamede, Portugal [Click for map]

Who: zaca

No specimen available

I must confess to be completely lost in trying to identify the specimen of this observation. I had no opportunity to do chemical testing on site, but I collected some apothecia that now decided to analyze. My surprise was great when confronted with the results of microscopy: clavate asci each with 8-spores and spores small – average dimensions: Me = 9.3 × 5 mm; Qe = 1.9 (N = 26) – and 1-septate. Now, I was waiting for simple spores, because in my view it should belong to the family Parmeliaceae. Given these results, which seem to refer to the family Physciaceae, could not find any genus to which might belong. What is it?



Proposed Names

29% (1)
Recognized by sight
58% (1)
Eye3 Eyes3
Used references: REF – The arachiform vacuolar body: an overlooked shared character in the ascospores of a large monophyletic group within Parmeliaceae (Xanthoparmelia clade, Lecanorales).
by Ruth Del Prado, Zuzana Ferencová, Victor Armas-Crespo, Guillermo Amo De Paz, Paloma Cubas, Ana Crespo. Mycological Research (2007), Volume: 111, Issue: Pt 6, Pages: 685-692.
29% (1)
Recognized by sight: Non-isidiate, non-sorediate and non-pustulate.
Used references: CNALH.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Jason Hollinger (jason)
2011-10-07 19:59:25 CEST (+0200)

I’ve never seen or read about these constrictions anywhere else. The Sonoran Flora very clearly states that spores are “simple” throughout the genus. (But it wouldn’t be the first time we found a mistake in these volumes!) Makes one wonder about other “oversimplifications” that might exist in the literature, too. Good job getting to the bottom of this! (I confess that I’ve never looked at a Xanthoparmelia spore. :)

I have something to add.
By: zaca
2011-10-07 19:43:48 CEST (+0200)

I continued to seach information about lichens related to this observation. As Jason suggested that this might be a Xanthoparmelia I looked for images of the spores of its members. First I encountered this webpage with an image of the spores of a Xanthoparmelia conspersa. They looked similar to what I observed and it is written that “Spores. Single celled, 1-septated”. I go on and next I found a scientific paper – REF – where it is stated that “All the Xanthoparmelia species had spores with a single smooth vacuole, which was peanut-shaped, with different degrees of constriction in the equatorial plane”. The photos included in the paper illustrate spores with different degrees of constriction in the middle of the internal vacuole. Again some of them looked familiar. The first one, for instance, is very illustrative and shows spores that when seen with a bad microscope like mine can be thought to be septate.

Based on this my conclusion is the following: what I observed were just the spores of a Xanthoparmelia.

Parasites can do many things
By: Jason Hollinger (jason)
2011-10-07 02:06:07 CEST (+0200)

They often form visible structures within the host substrate — be that thallus or apothecium. But maybe not always. I just can’t think of any other option. If this were truly a completely novel family of lichens(!) surely you wouldn’t expect it to look exactly like a Xanthoparmelia, right?

Maybe you are right.
By: zaca
2011-10-07 01:32:37 CEST (+0200)

I made two quick preparations. One with material of the thallus and another with material from a different apothecium. In the first one I saw the normal material of the thallus and no asci or spores. In the second I obtained the same result as before. So if this is the result of parasitism it is restricted to apothecia.
But, if it was a parasite I would see the structures from the parasite as well as the normal structures of the lichen. Or not? Is it usual that parasite completly destroi the asci of the host?

I would’ve bet anything this was Xanthoparmelia
By: Jason Hollinger (jason)
2011-10-07 00:12:59 CEST (+0200)

But I agree, I see no species of Parmeliaceae with septate spores. Note, by the way, that Physciaceae has brown septate spores. Teloschistaceae has colorless septate spores, but they are “polarlocular”, meaning they have a conspicuously thickened septum which your micrographs don’t show. Maybe you accidentally included a parasite in your slide preparation? (Or maybe the entire apothecium has been parasitized?) I can’t think of any other plausible theory.

Created: 2011-10-06 23:42:43 CEST (+0200)
Last modified: 2011-10-08 13:24:18 CEST (+0200)
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