Observation 70672: Parmotrema A. Massal.

When: 2011-06-23

Collection location: Sintra, Portugal [Click for map]

Who: zaca

No specimen available

Here are some of the features of this specimen:
- Growing on the bark of a pinus tree; Thallus gray;
- lobes well developped, ascending and wavy; some of them white mottled;
- lobe margins with cilia and slightly sorediate; no isidia;
- lower surface black, light brown or white mottled at the margins;
- chemistry on medulla: K-, C-, KC+ red.


Proposed Names

-29% (1)
Used references: Azores bioportal, CNALH.
Based on chemical features
29% (1)
Recognized by sight

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= Observer’s choice
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Add Comment
At the end,
By: zaca
2011-07-06 15:25:59 CDT (-0500)

for what matters KC + and KC + red rose are very close.
In my short experience, I have the same feeling about the KC reaction. I apologize for the outburst in the last comment, but in this case the red seemed to me obvious.

KC+red / KC+rose, it’s all a mess
By: Jason Hollinger (jason)
2011-07-06 10:20:04 CDT (-0500)

I tested every single one of my dozens of specimens of P. dilatatum / P. gardneri, as well as countless specimens of various other species of Parmotrema and Usnea and other genera with protocetraric and alectoronic acid, desperately hoping to find some way to read the KC reactions which could distinguish quantities and minor substances and anything else. (For example, usnic acid in addition to protocetraric in P. dilatatum may conceivably result in KC+pink turning yellow quickly or something, wouldn’t you think?) But I’ve found no useful patterns to the extreme variation in KC reactions. Some have a strong but very fleeting light violet-purple stage, and I think that only happens with alectoronic acid, but certainly not in all cases. Some give a deep red that lingers long enough to take a photo. Others barely have a fleeting pink before fading straight to nothing. Others have a golden stage, still others mix pink and/or red and/or yellow. It’s bewildering. I don’t even begin to understand what’s going on.

But in short: what I see in your photo is entirely consistent with the protocetraric acid reactions I see in Parmotrema species! :)

By: zaca
2011-07-04 12:58:21 CDT (-0500)

But we are looking for a species with KC+ red and not KC+ rose.
Thanks, Jason.

Doesn’t look like P. arnoldii to me
By: Jason Hollinger (jason)
2011-07-01 20:07:25 CDT (-0500)

But I could be wrong of course! It’s a “messier” narrower-lobed species. In North America we only see arnoldii in the north or very high in the southern mountains, so I wouldn’t expect it in Portugal either (although I see Sipman reports it for the Caribbean, if you believe it). There are several other choices all with KC+rose:

P. rampoddense — particularly broad smooth lobes with scattered cilia, pure gray with no yellowish tints at all
P. dilatatum / P. gardneri — more ruffled and typically with very few cilia or only scattered short cilia (very hard to find), anywhere from pure gray to quite yellowish (usnic acid in varying quantities in cortex)
P. robustum — don’t know the species (reported in Sipman’s key as “widespread in mountains” whatever that means, and his ranges are frequently wrong anyway)
P. mellissii — with very coarse soredia usually mixed with cilia (definitely not this specimen, but one of the other recent posts is possible)

I recommend rampoddense for this specimen, but dilatatum/gardneri (indistinguishable without TLC) are maddeningly variable (I have a whole box of collections of this group, and I haven’t been able to make any headway with it). Unfortunately I’ve packed away my Brodo, which distinguishes rampoddense from dilatatum/gardneri, sorry!

Oh, and I forgot P. dominicanum, reportedly very similar to dilatatum/gardneri but with yellowish soredia and no cilia at all (not a particularly useful character!)