Observation 109634: Parmelia saxatilis (L.) Ach.
When: 2012-09-13
(47.4394° 117.598° 684m)
Herbarium specimen reported

Notes: 02-04.07.2012-TNWR
P# 108.8367-8374.

Basalt rock, 8 inches above soil line. Amongst moss.

K+red (only parts of medulla), Cortex K+yellow, C- both.

Seems to be P. hygrophila

Images

261885
261886
261887
261888
261898
the cortication of the isidia — is this soft or hard? Seems hard?
261899
the cortication of the isidia — is this soft or hard? Seems hard?
261900
the cortication of the isidia — is this soft or hard? Seems hard?
261901
the cortication of the isidia — is this soft or hard? Seems hard?

Proposed Names

-5% (2)
Eye3
Recognized by sight
77% (2)
Eyes3
Used references: Parmelia hygrophila a new lichen species from the Pacific
Northwest of North America"(1992)

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

Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

Add Comment
Good, I agree with you
By: Jason Hollinger (jason)
2012-09-14 18:01:43 PDT (-0700)

P. saxatilis is actually a complex of species, but let’s not worry about that yet… largely because they haven’t been published! :)

and the roll continues :)
By: nastassja (Nastassja Noell)
2012-09-14 17:45:51 PDT (-0700)

Looking closer at the isidia…I see some of the isidia that rise like little towers of numerous isidia – almost like those drip sand castles that you make at the beach… so they stay in little balls, but the balls cluster together into little towers in well protected areas… so I wouldn’t call the individuals “long cylindrical” as in P. saxatilis but collectively they are… individually they look more granular like in P. hygrophila… but they are pretty shiny and corticate and have browned tips like in P. saxatilis, only about <10-20% look like they are disintegrating… tricky.

P. fraudans is out cause it really doesn’t look like there’s usnic acid.
And P. squarrosa is out because the rhizines are simple, not squarrose.

Trevor’s key in Parmelia hygrophila a new lichen species from the Pacific
Northwest of North America"(1992) puts the toss up between three characteristics:

A) Brown corticate tips are rare in P. hygrophila but common in P. saxatilis
B) Substrate: P. saxatilis is rarely over bark, while P. hygrophila is rarely over rock.
C) Range: P. hygrophila is found in more humid conditions, coastal, boreal, etc.

And since this was growing on basalt rock, in a relatively dry climate area…

I hereby name this lichen specimen Parmelia saxatilis

Haha!
By: Jason Hollinger (jason)
2012-09-14 00:12:56 PDT (-0700)

That just means you haven’t had the pleasure of using a good key yet. :)

My key said nothing about the
By: nastassja (Nastassja Noell)
2012-09-14 00:04:14 PDT (-0700)

softness and hardness of the isidia… thatd be cryptic without your explanation of how it looks under the dissecting scope.

This is why I run most everything by you Jason. You’re far better than any key :)

Tricky group
By: Jason Hollinger (jason)
2012-09-13 23:52:03 PDT (-0700)

Your key(s) talk about the “soft-corticate” isidia in P. hygrophila and P. fraudans, right? Substrate is only a guide, unfortunately.

P. saxatilis – isidia hard-corticate, shiny, usually conspicuously long-cylindrical; mostly on rock
P. hygrophila – isidia soft-corticate, dull, usually granular; mostly on bark
P. fraudans – same soft isidia, but tending to cluster more, lobes narrower, and usnic acid present but not always obvious; always(?) on rock

These soft isidia are hard to calibrate. At 30x or higher, you should be able to see the tips fairly clearly. If they are “polished” and shiny and well-formed (look at ones that haven’t been physically damaged, of course!), then it is probably P. saxatilis. If it looks like it’s cracking up and about to disintegrate and at most maybe matte-gloss but usually almost pruinose-looking, then it’s probably P. hygrophila or P. fraudans.

Sorry if you’ve already read all of this. I found it very confusing at first, but they aren’t quite as bad as they seem.

Created: 2012-09-13 21:56:36 PDT (-0700)
Last modified: 2012-09-14 18:02:29 PDT (-0700)
Viewed: 75 times, last viewed: 2014-10-29 13:54:27 PDT (-0700)
Show Log