Observation 109538: Peltigera didactyla (With.) J.R. Laundon
When: 2012-06-21
(47.4045° 116.4786° 707m)
Herbarium specimen reported

Notes: This one looks an awful lot like Psora, but it has soredia, and no apothecia. Odd…

Substrate: soil.

Habitat: Mima Mounds, intermound area (short grass prairie).

Features: Thallus 2-3mm across. Attached centrally. Light brown epruinose upper cortex, margins incurled, very very slight stubble on margins. White underside pruinose or lacking a cortex … don’t want to go slicing just yet, not much of this guy in the sample, have not come across him before… Green photobiont.

K+Y and R (but not norstictic acid); C+R (sparse), KC+orange. Seems to be UV-…

Chemistry rules out Placidium and Protopannaria which have no secondary lichen metabolites; and probably Psoroma which also usually tests negative in spot tests… could this be a bizzare non-apotheciated Psora or maybe even a brown Normandina is that even possible?

Images

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a whole bunch of soredia – this kinda looks like Goward’s key for Normandina pulchella
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Soredia?
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K test
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K test
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C test
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KC test
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the underside and the kinda bumpy margin.
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measurement.
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P test. Top 2 pieces are the mystery lichen and are obviously P-. The bottom P+Y one is a Cladonia used as a control.
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Proposed Names

55% (1)
Used references: Goward’s “Lichens of British Columbia” squamulose (don’t work for this one). Lendemere’s Key to Sterile crusts (total dead end).
Based on chemical features: K+Y and R (but not norstictic acid; C+R (sparse), KC+orange.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

Add Comment
“var.” extenuata
By: Jason Hollinger (jason)
2012-09-13 12:23:11 PDT (-0700)

I wouldn’t expect P. extenuata in this habitat, but could be wrong. It is very young, but already tending to polyphylly. Rhizines haven’t even developed yet, so no way to tell from those. Triterpenoids are fatty acids, so negative spot tests. Trisepsides… oh, that must be a generic term for orcinol depsides and others(?) That must include gyrophoric acid. Still, shouldn’t give K+. I’m just wondering if that’s a false positive because of the K dissolving tissues and revealing the underside of the cortex or something.

Thing to do: start searching similar habitats carefully… uhhh… after you get back from Argentina, that is! You’re bound to turn up many more now that you know what to look for. It takes a trained eye to spot P. didactyla and P. extenuata most of the time. Probably will find P. lepidophora, too, in same situations. Equally inconspicuous 99% of the time. Disturbed dry dirt banks, esp. side of roads (didactyla and lepidophora), and shaded mossy banks (extenuata). Don’t forget to look for P. venosa on shaded dirt trailbanks and road cuts, as well. But they’re harder to overlook!

Sonoran Flora
By: nastassja (Nastassja Noell)
2012-09-13 12:02:08 PDT (-0700)

lists that the Peltigera genus does sometimes have hopane triterpenoids and tridepsides… how that translates into spot tests, Brodo’s chart in LNA doesn’t cover.

And “Lichens of British Columbia” lists that Var. extenuata has methyl gyrophorate and gyrophoric acid, which the latter is K-, C+pink and KC+red…

Seems like this mystery will have to be put onto the shelf for now :) …

But if I have time, I will K-test my other Peltigera’s just to see if theres a K+Y trend in them out here… that would be fascinating if there was!

Thanks for your help Jason :)

This is a wee little baby specimen
By: Jason Hollinger (jason)
2012-09-13 11:44:49 PDT (-0700)

But it’s unmistakable. All of these things (algae, rhizines, etc.) are easy to misdiagnose when this small. I admit, though, that I was really hoping that there was a mixture of things here, and that maybe you’d spot tested a look-alike accidentally, or something. I don’t know what’s up with that K+y thing. I’ve never done a spot test on a Peltigera of any species, though, so I have no experience in this.

But spot test still K+Y
By: nastassja (Nastassja Noell)
2012-09-13 11:39:20 PDT (-0700)

But despite spot test, there is a tomentose underside, and the distinctly looking beginning of rhizines… and maybe the photobiont is Nostoc, maybe there are both cyano and chloro, cause my eyes are tripping me up, and my photo for the last K+Y test shows what seems like maybe is both?

Thank you for your help Jason :) despite my lack of belief at the beginning. But it was shocking – Peltigera?! I was hoping for some previously unfound sorediated Psora! My mouth was agape :)

And I see that compared to other photos on MO, 3mm is not all that small… So I was very wrong on so many counts. Eeeeek! I really want it to be a Psora though.

Um. I might need to stick my foot in my mouth :)
By: nastassja (Nastassja Noell)
2012-09-13 11:22:57 PDT (-0700)

So there appears to be what could be considered the begining of rhizines…

Can’t be, no way :)
By: nastassja (Nastassja Noell)
2012-09-13 10:55:08 PDT (-0700)

Did you see how small these are — about 3mm! Not even close to the 1-5 cm that CNALH lists.

Additionally…I’m pretty sure its a green algae, and not Nostoc… unless there’s some algae switching going on… or my eyes are fooling me…

And… there’s no rhizines. And and… the chemical tests… particularly the K test, obviously K+Y, no way around it; the KC and C tests are debateable, but not the K+Y test. And and and… the thallus isn’t tomentose!!!

But I do see what you are saying with the soredia…

Maybe I got the lack of a lower cortex wrong?

I’ll run the tests again… :)

Yay! I can help!
By: Jason Hollinger (jason)
2012-09-13 10:42:49 PDT (-0700)

This is totally Peltigera didactyla… But what’s up with those spot tests?? Let’s just blame those on the diminutive size…

Created: 2012-09-13 10:21:02 PDT (-0700)
Last modified: 2012-09-13 12:07:22 PDT (-0700)
Viewed: 80 times, last viewed: 2016-04-18 01:24:35 PDT (-0700)
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