Observation 85706: Pertusaria amara (Ach.) Nyl.

When: 2012-01-02

Collection location: Kopachuck State Park, Pierce Co., Washington, USA [Click for map]

Who: damon brunette (damonbrunette)

No specimen available

Proposed Names

28% (1)
Recognized by sight
28% (1)
Recognized by sight: I think this is the most likely candidate, based on “gestalt” appearance: expect a pinkish/purplish reaction in the soralia with KOH followed by bleach. It should also be extraordinarily bitter to the taste.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Thanks guys!
By: damon brunette (damonbrunette)
2012-01-09 18:32:02 EST (-0500)

I had no idea about tasting lichens! Will give it a whirl next time.

I hesitate to recommend relying on bitterness
By: Jason Hollinger (jason)
2012-01-05 16:43:02 EST (-0500)

I don’t think everyone tastes it the same. I’ve tasted it very strongly in some, and not at all in others. There must be an environmental component to it. And as you say, I don’t know if anyone ca state categorically that no other species can ever taste as bitter… But it is at least useful for verification!

It is easy
By: amadej trnkoczy (amadej)
2012-01-05 16:27:19 EST (-0500)

to prove Petrusaria amara, or more accurately, it is easy to prove that it is not. Just lick its surface a bit. It IS very bitter. I am not sure this is a sufficient condition to be positive in P. amara. May be there are other similar species, which are bitter too. Jason will know.

Need chemistry
By: Jason Hollinger (jason)
2012-01-05 13:06:27 EST (-0500)

There are various Biatora, Pertusaria, Trapelia(?), etc. which will grow thin greenish crusts with well-delimited soralia like this. If you have time, try applying KOH and bleach separately, and KOH followed by bleach to both the smooth greenish bits and to the raised granular soralia. Preferably using a toothpick or something like that under a dissecting scope. If all these are negative, then you’ll need UV (350 nm) and PPD, both pretty hard to come by. Even then you might require TLC to get to the bottom of some specimens.

Created: 2012-01-04 23:35:31 EST (-0500)
Last modified: 2012-01-05 13:49:10 EST (-0500)
Viewed: 63 times, last viewed: 2017-09-06 10:01:15 EDT (-0400)
Show Log