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|I’d Call It That||3.0||6.03||1||(Andrew)|
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I send mine (lichenicolous fungi) to Paul Diederich in Luxembourg. I got lucky and sent him something interesting once, so he seems to tolerate the occasional package. I can give you his address… privately.
Jim Bennett of UW-Madison (lichenology) thinks it might be parasitized by lichenicolous fungus. He doesn’t work with things like that and doesn’t know anybody who secializes in that group.
I may be able to revisit this site and even probably find this lichen again and take samples. I’ll keep it in my to-do list.
That leaves a little under half the genera of Parmeliaceae unplaced. Wow.
From a field lichenologist’s perspective, I would definitely have included:
with the cetrarioid, too. But clearly outward appearances can be misleading. (Oh yes, and the new Usnocetraria, which they seem to be missing.)
I’ve always thought of them as being generally more fruticose than the parmelioids, thick and shiny (even shinier than most parmelioids), and usually with conspicuous, often raised, large black pycnidia. Parmelioids, by contrast, are generally flatter, thinner (more “leaf-like”), and when they have pycnidia at all, they are immersed and just appear as tiny black dots flush with the surface.
In any case, it is a very useful, if possibly somewhat artificial, way to divide the family into two halves. (Other things like Hypogymnia, Menegazzia, Letharia, Evernia, Pseudevernia, Alectoria, Bryoria, Usnea, etc. are so totally different as not to pose a problem with field identifications.)
Two Wikipedia pages help to pin down the concept of Cetrarioid lichens. The Wikipedia page on Parmeliaceae lists six “clades” in that very large family:
Alectorioid clade (3 genera)
Cetrarioid clade (8 genera)
Hypogymnioid clade (4 genera)
Letharioid clade (2 genera)
Parmelioid clade (26 genera)
Psiloparmelioid clade (2 genera)
“However, this still leaves roughly 42 Parmeliaceae genera unplaced.”
But then another Wikipedia page offers a List of Parmeliaceae genera, and assigns each genus to its clade, or indicates that it is not yet assigned. Five of the eight Cetrarioid genera should be pretty easy for us to remember :-)
I also wondered if some environmental factors had induced this seemingly different morphology, especially all the small apothecia. Couldn’t find photos that really came all that close to this observation. A bit more data would be helpful, as Jason suggested. What color is the lower cortex, and how do the upper cortex and medulla (separately) react to the K reagent?
I don’t know about Chris, but I’m just guessing still. It’s especially stark seeing it growing side-by-side with the (normal) P. stellaris in the first photo, for example. But honestly, I’m having trouble coming up with other plausible genera! I’d still not rule out Imshaugia. It is a “cetrarioid” genus (or at least I think of it as such, I’m not sure there is a strict definition of the term), so it has lots of pycnidia, it’s shiny, and it’s less flat / more ruffled. Maybe the environmental conditions in this particular location are causing this “stressed” form. I’ll post my photos from New Mexico, and you can almost convince yourself of small-scale similarity…
I have to trust your judgment and experience arriving at the genus Physcia, and then whittling it down to P.stellaris. But why is this lichen the way it is? Do you think it’s affected by some disease or stress condition? I looked at hundreds of photographs but couldn’t find any with such large numbers of pycnidia and tiny weird apothecia. Something’s going on here.
Assuming that the lower surface is white or tan, the keys in Hinds and Hinds lead to these choices, for New England anyway. There may be more choices available in Wisconsin (Hinds and Hinds, 2007, p.84):
1a. Upper surface with obvious white spotting … Physcia aipolia
1b. Upper surface without obvious white spotting, or if present, medulla K- … 2
I don’t see white macullae on the upper surface, nor any hint of brown to orange brown in those admittedly small and puckered apothecia, so Physcia stellaris is looking interesting. The abundant and prominent pycnidia are striking. CNALH admit that pycnidia are at least common in all three species, but they are reported as more or less abundant in Physcia stellaris.
Turning to Thompson’s key to the Physcia of Wisconsin, an esorediate Physcia in Wisconsin without marginal cilia and found on bark leads to only two species, Physcia stellaris and Physcia aipolia (Thompson, 2003, p.182):
4(3). Medulla K+ yellow (atranorin in both cortex and medulla) … 5
4. Medulla K– (atranorin only in cortex, not medulla); on bark, rarely rocks … P. stellaris
5(4). Upper surface with white spots (algae unevenly distributed); medulla loose … 6
5. Upper surface evenly colored; medulla paraplectenchymatous; on rocks … P. halei
6(5). Thallus whitish or gray-white; on bark; spores 16–29 × 7–11 μm … P. aipolia
6. Thallus blue-gray or ashy gray; on rocks; spores 15–22 × 7–10 μm …P. phaea
Hinds and Hinds, 2005, The Macrolichens of New England
Thompson, 2003, Lichens of Wisconsin
The little guys are different species. I’m drawing a blank on genus, too! Those two names were just working hypotheses that should be easy to confirm or refute.
It was growing on the fallen log, of unknown species, badly disintegrated as far as I remember. Too bad I didn’t peel the tissue to get the photo of the underneath either. I know – amateurs like myself are annoying. Also, I assumed that those lichen on the perimeter of the lichen in question, with light brown or black apothecia are different species that are getting impinged on by the bigger guy here. Am I wrong here? (It seems to me that your ID as P.aipolia or I.placorodia is based on those specimen with prominent apothecia)
This sure doesn’t look like a typical form of anything I know either. I would be very interested in seeing the underside. Does the upper surface have a mottled appearance or is it a uniform smooth even gray? It would also be interesting to see how it reacts to K. Would also be good to see it when dry. I’m thinking either Physcia aipolia (K+ weak yellow, mottled, dull when dry) or Imshaugia placorodia (K+ deep strong yellow, smooth and even, ~shiny). Both should be white underneath with white rhizines. Surely, an odd form for either. Interesting to find so many specimens all doing the same thing. Oh, and what sort of tree is it growing on (hardwood or conifer)?
This is very distinctively looking lichen – I surprised myself by not being able to pin it down even to a genus level. I just didn’t see anything similar in my guides. Maybe I didn’t pay attention…
Created: 2011-04-16 21:56:51 CDT (-0400)
Last modified: 2011-04-16 22:53:46 CDT (-0400)
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