Observation 97178: Pertusaria DC.

When: 2012-06-09

Collection location: Estádio Nacional, Oeiras, Portugal [Click for map]

Who: zaca

No specimen available

Growing on bark.


Chemical reactions.
A – The marks of the reaction made 4 days ago; B – scratching medulla for the new tests.
New spot tests on medulla.

Proposed Names

58% (1)
Eye3 Eyes3
Based on microscopic features

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
It was a good idea at the time…
By: Jason Hollinger (jason)
2012-06-14 05:14:01 WIB (+0700)

I’m guessing this is either stictic acid or thamnolic acid. Loxospora is a common sterile epiphytic crust with well-developed whitish/grayish thallus that contains thamnolic acid. But it doesn’t look promising. I’m not sure what it could be if it’s Pertusaria. It would really be nice to see either a definite apothecium or perithecium, or a definite soralium or pustule. This specimen is some intermediate thing that could go either way. I’ve tried all my keys, and I’m just stumped. It’s not clear that P and UV would help, but having those tests would at least narrow down options (P distinguishes stictic and thamnolic acids, UV can reveal lichexanthone and maybe other accessory substances).

Whats going on?
By: zaca
2012-06-14 04:31:04 WIB (+0700)

This was supposed to be a Pertusaria velata. Accordingly a C+ red reaction was expected, beyond a K- or K+ reaction. That was not what I observed. Ther was no C+red reaction, but the K+ yellow reaction was intense, I think the one caused by thamnolic acid. I uploaded already the photos with the new reactions and also a photo where the previous reactions on thallus are still visible. Ironically, there is some red in the KC reaction of 4 days ago. So, what is this?

By: Jason Hollinger (jason)
2012-06-13 06:54:49 WIB (+0700)

This is more typical of the species.

This one seems to me even closer to …
By: zaca
2012-06-13 05:38:51 WIB (+0700)

Pertusaria velata.
Look at the verrucas, at the margin and compare with Sharnoff photos.

[Edited: In the field it seemed sterile, so I didn’t collect a sample.]

Created: 2012-06-13 05:37:57 WIB (+0700)
Last modified: 2012-06-13 05:37:59 WIB (+0700)
Viewed: 52 times, last viewed: 2017-06-13 14:55:47 WIB (+0700)
Show Log