Observation 87201: Lecanora muralis (Schreber) Rabenh.

When: 2012-01-28

Collection location: Stebbins Cold Canyon Reserve, Solano Co., California, USA [Click for map]

Who: Byrain

No specimen available

Growing on an exposed rock embedded into the middle of the trail next to obs 87128, possibly the same though I am unsure. It tested K+ yellowish and C- on the Q-tip or bluish on the thallus (See pics) if that has any significance.

Proposed Names

28% (1)
Recognized by sight
61% (2)
Eye3 Eyes3
Recognized by sight: lobed margins, lobes flat (not convex or inflated)
Based on chemical features: despite the apparent spot tests

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Gotta love that
By: Jason Hollinger (jason)
2012-01-30 10:32:49 PST (-0800)

“Thallus usually KC-… cortex KC+y…”

Err, which is it, then? :)

The Sonoran Flora is not the only reference that frequently mischaracterizes spot tests. The chemistry is usually reliable, however. It’s definitely worthwhile learning the dozen or so common “lichen substances” and their associated spot tests. In this case, the cortex is supposed to have usnic acid. But the British flora I think has it right: it is in low concentration, so it is at best KC+ pale yellow.

Lecanora muralis spot tests
By: Chris Parrish (kitparrish)
2012-01-30 06:48:51 PST (-0800)

Here is what two references say about Lecanora muralis spot tests:

“Thallus C-, K- KC+ pale yellow, P + or – yellow, UV+ dull orange (usnic acid, zeorin, +/- murolic acid, +/- psoromic acid)” (Smith et al., 2009, Lichens of Great Britain and Ireland, p.491)

“Thallus (in the Sonoran region) usually K-, C-, KC-, P-; cortex usually KC+ yellow; medulla usually KC- … cortex with usnic acid, or occasionally isousnic acid; medulla almost always with zeorin, usually also leucotylin, other triterpines, and fatty acids, and occasionally various depsides, depsidones or unknowns.” (Ryan et al. in Nash, 2004, Sonoran Flora, Vol. 2, p.241)

“As delimited here, Lecanora muralis is an extremely variable taxon, probably representing a complex of species” (Ryan et al., op. cit.)

spot test blues
By: Jason Hollinger (jason)
2012-01-30 00:11:30 PST (-0800)

I could swear I’ve gotten poor results for spot tests on L. muralis, too, but I can’t find a single case in my notes where I actually recorded even performing a spot test on one!

By: Byrain
2012-01-30 00:01:54 PST (-0800)

I’ve studied this species better and it appears to have a variable K test (usually k-). Though this really does resemble many pictures online, I think L. muralis looks like a good name till further notice. And yes, I’m starting to see how this looks the same as the other specimen. :)

Gotta be Lecanora muralis
By: Jason Hollinger (jason)
2012-01-29 23:40:56 PST (-0800)

I’m used to it being a different color, but I just don’t see what else this can be. Surely this is the same thing in observation 87128, too, no?

Created: 2012-01-29 23:29:53 PST (-0800)
Last modified: 2012-01-30 00:02:07 PST (-0800)
Viewed: 49 times, last viewed: 2017-06-10 06:38:28 PDT (-0700)
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