Observation 116364: Cladonia petrophila R.C. Harris

When: 2012-08-16

Collection location: Governor Dodge State Park, Wisconsin, USA [Click for map]

Who: Andrew Khitsun (Andrew)

Specimen available

Proposed Names

31% (2)
Recognized by sight
78% (2)
Eye3 Eyes3
Based on chemical features: K- underneath squamules, growing directly on rock in large colony

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Which means it’s official
By: Jason Hollinger (jason)
2014-06-22 19:57:56 PDT (-0700)

You should throw away both of those UV lamps! For whatever it’s worth, UV was by far the hardest one for me to learn to interpret reliably, too. :(

ID confirmed by Jim Bennett
By: Andrew Khitsun (Andrew)
2014-06-22 19:43:45 PDT (-0700)
Should get UV+ off underside of Cladonia
By: Jason Hollinger (jason)
2012-11-12 16:28:36 PST (-0800)

Without any additional preparation. But it may be weaker than these other genera. The UV+ fibers could be from tissue paper. Those tend to be stronger UV+ than anything a lichen has to offer. I’m wondering if quality control leaves something to be desired with this UV light. I figured it was emitting such a broad spectrum that it was guaranteed to activate any of these UV+ substances, and that the only risk was that it would cause anything white to glow a little purple-blue. But using the control, it should be easy to distinguish between true UV+ and “fake” UV+ just because it’s white and reflecting what little short-wavelength visible light the UV light is putting out.

Of the ones mentioned here, I only have Evernia handy.
By: Andrew Khitsun (Andrew)
2012-11-12 16:06:37 PST (-0800)

And I didn’t see anything special on its medula.
On the other hand, there are some hair-like thingies lying on the surface of this Cladonia. They’re semi-transparent, and shine neon-blue under the light. I think this test might require some practice, and medula should be exposed properly (it’s very hard to do in Evernia of this Cladonia)

Yes, I have, and it’s worked great for me
By: Jason Hollinger (jason)
2012-11-12 15:49:21 PST (-0800)

I really hope I haven’t convinced a bunch of people to buy a crappy product! There are a number of common things that give a great UV+ white or “ice blue” reaction. Canoparmelia, Cetrelia, Tuckermannopsis, Evernia, Parmeliopsis, for example. Check it out on them (medulla in all cases). Better yet, take a few of those, expose a bunch of white medulla, take some others like Parmelia or Physcia or Parmotrema, expose their medulla, too. Then go in a pitch black room and compare them under UV. If you don’t see a difference, then I caused you to waste $10.

I haven’t had a chance to see anything yet with this light (or any other light for that matter)
By: Andrew Khitsun (Andrew)
2012-11-12 15:34:40 PST (-0800)

I’m using that small blacklicht from GermJuice.com. Has anybody tested that thing? But again, I never had positive reaction yet – maybe I’m not looking in the right places.

Uh oh, we’re in trouble again…
By: Jason Hollinger (jason)
2012-11-12 12:05:48 PST (-0800)

I really thought we had it. I’m not sure if there are any other plausible options. Let’s leave it at C. petrophila until you can get second opinions on the tests, or someone else can give us additional options.

Except I can’t get anything out of UV test :-((
By: Andrew Khitsun (Andrew)
2012-11-12 10:29:29 PST (-0800)
That’s perfect!
By: Jason Hollinger (jason)
2012-11-11 22:17:04 PST (-0800)

This makes so much more sense as Cladonia petrophila. I thought it was weird that it appeared to be growing directly on rock. I bet this also looks smaller than C. apodocarpa, doesn’t it? According to my notes, even though it is supposed to have fumarprotocetraric acid, I still got K- on the underside of every specimen I’m positive of (as verified by UV+ ice blue test). Sometimes the cortex would give a weak K+y reaction, though.

I didn’t get any response to K or C :-(
By: Andrew Khitsun (Andrew)
2012-11-11 17:19:58 PST (-0800)
Ah, but this is supposed to be sterile
By: Jason Hollinger (jason)
2012-11-10 22:25:13 PST (-0800)

Best resource is this Lendemer & Hodkinson 2009 Oh crap, it’s missing the C. subcariosa group because those do occasionally produce podetia. Anyway, I think C. apodocarpa is the most likely choice. Try K test underneath one of the squamules. Look especially for K+ yellow right away (C. apodocarpa has both atranorin and fumarprotocetraric, so it will start yellow then turn dirty brownish after half a minute or so). You’re mostly trying to rule out C. polycarpa, and that group. I think they mostly are K+ yellow turning red. It’s also worth doing a C test to check for that funky C+ green reaction of C. strepsilis. I’m ruling out C. robbinsii because the squamules aren’t yellowish enough (no usnic or barbatic acids).

Good-looking but sterile…
By: Andrew Khitsun (Andrew)
2012-11-10 18:17:34 PST (-0800)

Created: 2012-11-10 18:13:30 PST (-0800)
Last modified: 2015-12-20 18:32:14 PST (-0800)
Viewed: 75 times, last viewed: 2017-06-14 07:27:45 PDT (-0700)
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