Observation 103418: Pertusaria amarescens Nyl.
When: 2012-07-28
Who: zaca
No herbarium specimen

Notes: The main difference to the specimen in observation 103417 is that this one lacks soralia.

Proposed Names

29% (1)
Based on chemical features
58% (1)
Eye3 Eyes3
Used references: See the comments.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

Add Comment
Congratulations on finally getting the British Flora!
By: Jason Hollinger (jason)
2012-07-31 15:33:31 EDT (-0400)

I’m sure you will find it helpful.

Jason, your clinical eye is impressive.
By: zaca
2012-07-31 15:05:17 EDT (-0400)

I think that you are right, since besisdes the slightly difference in chemistry there are also differences in the thickness/wartness of the thallus and in the dimensions of soralia of the two specimens (this one and the one in observation 103417), as you mentioned.
Finally, I received the British Flora. So, now I can see the details there.

British Flora shows two similar species
By: Jason Hollinger (jason)
2012-07-31 02:02:47 EDT (-0400)

P. amarescens – thallus thin, minutely cracked-areolate, grey to ±yellow-gray in patches; soralia 0.1-0.3 mm, fleck-like, pale grey-white; K+y, C+o, KC+o, P+o/r
P. flavicans – thallus thick, smooth to coarsely warted-areolate, yellow- or green-grey; soralia 0.3-0.8 mm, ±rounded, pale yellow-green; K-, C+o, KC+o, P-

Both occur in macaronesia, on rocks. In the description for P. amarescens it describes it as “Like P. flavicans but thallus pale primrose-yellow to dull olive-grey, much thinner and more delicately rimose-cracked…” It also has stictic ± norstictic acid in addition to the thiophanic acid that P. flavicans has (the source of the yellowish coloration, also UV+ orange).

You may well have both species. This specimen looks distinctly K+ yellow, what do you think? (The other is a bit ambiguous.)

Created: 2012-07-30 18:59:50 EDT (-0400)
Last modified: 2012-08-02 19:10:41 EDT (-0400)
Viewed: 68 times, last viewed: 2016-10-24 19:14:11 EDT (-0400)
Show Log