Observation 212635: Pertusaria lecanina Tuck.

When: 2015-08-05

Collection location: Santa Barbara Co., California, USA [Click for map]


Who: J-Dar

Specimen available

On Quercus agrifolia trunk bark in old coast live oak woodland within a mile of the ocean, at the western end of the Transverse Range.

Thallus thin, crustose, greenish-yellow, K+Y turning orange to reddish (see photos). Eruptions of soredia on thallus that look sort of like young apothecia K+R, turning red quicker than thallus. C test on thallus shows yellowish. KC test Gold. Should be violet for P. amara.

[Update 1: Spores 2 per ascus, norstictic acid major. soredia absent]
[Update 2: UV+Orange, photo added]


2-spored Ascus
K+ reaction at top right. K+ dark orange in small reaction at bottom right, with C+Y test showing as the lightly dirty yellow to the far right edge. KC+ goldish reaction in center bottom of photo
New Photo. Detail of spot test K+
Asci in KOH
Asci in KOH
Norstictic Acid crystals, in KOH
Apothecium detail
UV+Orange. Cell Phone on night photo mode, not exactly sharp, but it works!

Proposed Names

63% (3)
Recognized by sight
-73% (3)
Recognized by sight
-61% (2)
Recognized by sight
63% (3)
Eye3 Eyes3
Based on microscopic features: 2-spored ascus

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Wise choice!
By: Jason Hollinger (jason)
2015-10-15 18:48:10 -05 (-0500)

Clearly I’m already blind.

OK! I quit!
By: zaca
2015-10-15 18:42:00 -05 (-0500)

As I’m not yet completely blind … I’m not a lichenologist!

Oh I understand!
By: Jason Hollinger (jason)
2015-10-15 18:31:33 -05 (-0500)

You’re contrasting “yellow” and “orange”! Haha! I’ve long given up any hope of getting lichenologists to agree on whether xanthones are C+ yellow or C+ orange. :)

Have you seen all the ways “usnic” yellow is described in the literature?? And what about the KC reaction of gyrophoric acid and kin? The description of the K reaction of some anthraquinones like russulone are all over the board from red to blue! Lichenologists are clearly all collectively color blind!!

Too funny. I honestly didn’t even notice that we were switching back and forth semi-randomly between yellow and orange. Something in my brain translated both words to mean the same thing in this context. :)

Talk about confusion!!

We better quit while we’re ahead, and leave Elix’s alleged K+y C+y psoromic acid for a more diligent audience member. ;)

I think all of us are confused …
By: zaca
2015-10-15 18:21:46 -05 (-0500)

because something is hidden in the descriptions or there are contradictions there. Let me summarize:

Elix says that “Thiophanic acid” produces C+ orange. Apparently. this is confirmed by the spot tests/chemistry of the three species under consideration given in CNALH (from Sonoran Flora) as follows:

P. lecanina:
Spot tests – K+ yellow to red, C+ orange, KC-, P+ yellow to orange, UV+ orange-red
Secondary metabolites – norstictic and thiophaninic acid (both major) and connorstictic acid, 2-chloro-6-O-methylnorlichexanthone, 4-chloro-6-O-methylnorlichexanthone, and +/- gyrophoric acid (all minor)

P. neolecanina:
Spot tests – K+ yellow to red, C+ orange, KC-, P+ yellow to orange, UV+ orange-red;
Secondary metabolites – norstictic and thiophaninic acid (both major) and connorstictic acid (minor).

P. wulfenoides:
Spot tests – K+ yellow to red, C+ orange, KC-, P+ yellow to orange, UV+ orange-red;
Secondary metabolites – norstictic and thiophaninic acid (both major) and connorstictic acid, 2-chloro-6-O-methylnorlichexanthone, 4-chloro-6-O-methylnorlichexanthone (all minor).

On the other hand, the paper by Boqueras&Llimona gives for a species with the same major lichen substances the following:

P. luteola:
Spot tests – K+ yellow to red (red crystals), C+ yellow and KC+ orange reddish, P+ yellow; epithecium K-;
Secondary metabolites – thiophaninic acid and norstictic acid.

It happens that the spot tests of the species in this observation coincides with that of P. luteola.

Sorry, I’m still confused I guess
By: Jason Hollinger (jason)
2015-10-15 17:42:22 -05 (-0500)

Thiopaninic acid should be C+y. Whether it is detectable just depends on the concentration.

That was not the point!
By: zaca
2015-10-15 17:31:49 -05 (-0500)

The intriguing point is that there is a species with C+ yellow (and, in addition, K+ yellow to red (red crystals)and KC+ orange reddish) with the lichen substances: Thiophaninic acid and norstictic acid!
I don’t pretend that the one in this observation is that species.

Apparently P. luteola is poriform, not disciform
By: Jason Hollinger (jason)
2015-10-15 17:25:35 -05 (-0500)

According to Archer & Elix 2015 (world key). But otherwise identical? (Maybe spores are multi-layered, key doesn’t mention that.)

It’s as if “they” wrote down every combination of number of spores, chemistry, disciform/poriform, rock/bark and created a species for each combination! :) And there are a lot of combinations!!

Thanks, Jason,
By: zaca
2015-10-15 17:15:36 -05 (-0500)

for clarifying the point connected with the spot test produced by “Psoromic acid”. Of course, I trust you in that matter.
But, for me, there is still and intriguing point:
If you remember related my observations of Pertusaria last year I found a reference about the species in the Iberian Peninsula (see observation 163519). Now I recalled that reference and looked for species with C+ yellow reaction: One is my very well known P. hymenea that can have very variable chemistry (three chemical races are mentioned in that paper); the other is P. luteola, a corticolous species. What is strange is that the chemistry of this species is given there as follows:
CHEMISTRY: thallus K+ yellow to red (red crystals), C+ yellow and KC+ orange reddish, P+ yellow; epithecium K-. Thiophaninic acid and norstictic acid.”
These are precisely the reactions we have been discussing and the lichen substances mentioned are the same referred in the previous messages. How is it possible?

I must comment on a few of zaca’s points
By: Jason Hollinger (jason)
2015-10-15 16:25:40 -05 (-0500)

1) Psoromic acid is K-, C-, KC-, UV-, but P+ intense orangish yellow. It’s a little disturbing that this otherwise apparently excellent reference calls it K+y and C+y. Elix is widely considered a world authority on lichen chemistry. We all make mistakes, but… ??!! Is there some subtlety I’m missing?

2) The norstictic acid in Pertusaria is usually (always?) in the medulla, often only in the medulla of the warts or immediately associated with the apothecia. In my experience it is quite common to get K- or just a weak slow K+y on the thallus surface, despite abundant norstictic acid inside the warts. Look carefully for any hint of reaction in cracks in the thallus. Or better yet, slice a wart / apothecium in half and test that directly and remove all doubt.

3) The xanthones in Pertusaria, by contrast, are in the cortex. Although, sometimes they, too, will only be found associated with warts / apothecia. There are some species in southeastern North America with just a tiny yellow “nipple” on top of the wart, but will otherwise be C- KC- UV-.

4) I have to agree with zaca’s mistrust of the literature. Just the other day I was trying to key out a known species in the world key only to find it wasn’t in there(!) There is still some minor contradictions in various literature sources, and far more wide spread incomplete understanding of the range of variation within species. (This latter point still applies to most lichens in the world!)

5) The Sonoran Flora claims P. wulfenoides has been collected on a wide range of trees and siliceous rock. There are actually quite a few species which can be found on both bark and rock, although usually they will prefer one or the other. I bet in Great Britain it prefers rock. In Arizona I found it exclusively on bark (5 specimens), while a similar but different species was the one commonly on rock (P. tejocotensis).

OK, let’s put this particular one in a sleeping mode.
By: zaca
2015-10-15 15:11:13 -05 (-0500)

But I will make some remarks about some points related with the comments in this observation:

1) I you gave a look to my observations in this genus you certainly noticed that for many of them I could not reach a name. Mainly because I was not able to find at the time as well as presently any reliable checklist of the species in this genus existing here. For someone starting to observe lichen this is a fundamental instrument.

2) There as well as here, in the case of uncommon or less known species, the references can be contradictory: For instance, referreing to P. wulfenioides you said that “P. wulfenioides keys out under saxicolous species in Lumbsch 1999 Revision of Pertusaria (The Bryologist 102(2) pp. 215-239)” while in my message I provide links where that species is mentioned to be corticolous and a photo taken on a bark substract.

3) For a long time I searched for a publication where one can find the result in the spot tests as consequence of a certain chemistry. Some time ago I found something that I would like to share with you:
There you can find that, for instance, norstictic acid and thiophaninic acid will produce K+ yellow to red and C+ orange, respectively, and therefore a KC+ golden or red-orange reaction is expectable. What in my opinion is less well understood is the K+ yellow reaction. If it was C+ orange, then everything would be clear. If you make a search in that paper for “C: Yellow” you will find just one subtance that will produce it “Psoromic acid”. This compound was not referred for any of the species under consideration.

Let’s put this one to bed!
By: J-Dar
2015-10-15 11:54:55 -05 (-0500)

Thanks gentlemen, that was a fun debate, and quite the introduction for me to the genus Pertusaria. I see why Zaca posts so many observations of the genus, with the lively chemistry and widely differing morphology, it is a fun one to work through.

I don’t trust the spot tests in Sonoran Flora either! :)
By: Jason Hollinger (jason)
2015-10-15 11:14:45 -05 (-0500)

You can, however, trust the major secondary compounds they list, in this case thiophaninic and norstictic acids. Norstictic is established beyond a shadow of doubt thanks to your lovely microscopic photo of the red needle-shaped crystals forming in K. Thiophaninic acid gives me C+/- yellow-orange or orange (depends on the strength sometimes the C test is negative), and KC+ strong orange (very reliable and strong, never red, ignore them if that’s what the Sonoran Flora claims it should be).

So, you’ve convinced me concerning the chemistry.

You should see a fairly strong UV+ orange (not yellow) given that you actually got a C+ test (and because the thallus has a visibly yellowish cast). But UV is so much less reliable than KC in this case, I wouldn’t consider a UV- test to be a deal-breaker.

One other thing that distinguishes P. neolecanina is that it has two-layered spores, yours are clearly one-layered.

If you are seeing apothecia covered in thick pruina, whatever the pictures show, you must really have a genuinely disciform species. Poriform species shouldn’t have thick pruina.

Concerning substrate, the Sonoran Flora claims both species are found on oak bark in the Sonoran region.

P. wulfenoides does look very similar. It is in the Sonoran Flora, so should be a description on CNALH on-line. It also has two-layered spores, and should have “mostly” four-spored asci, as well. Like neolecanina, it too is way out of range, being an inland species. (I saw some recently in the mountains of southern Arizona, e.g.)

Fortunately, Pertusaria is a conspicuous genus, so as zaca suggests, the range of the Sonoran species should be relatively reliable in the Sonoran Flora maps. It’s the obscure little things like, say, Peccania, or chemically / morphologically ambiguous genera like Xanthoparmelia, that I wouldn’t trust the range maps for.

Summary: you’ve convinced me despite my earlier mistake concerning poriform apothecia. I’m going to vote for P. lecanina. It should be relatively common in Santa Barbara.

By: J-Dar
2015-10-15 11:05:50 -05 (-0500)

Hey Zaca, this observation is corticolous, from oak tree bark, which is consistent with P. wulfenioides, P. neolecanina and P. lecanina, all of which also are reported to have norstictic and thiophaninic acids.

From CNALH regarding P. neolecanina, “Chemically it agrees with P. lecanina which also has two-spored asci. This species, however, is readily distinguished by its disciform apothecia and the single-layered ascospores.” What is meant by single-layered ascospores? We’ve already been over the disciform vs poriform apothecia, and it seems you and Jason both agree this specimen leans toward poriform, so “readily distinguished” is not quite right!

P. wulfenioides keys out under saxicolous species in Lumbsch 1999 Revision of Pertusaria (The Bryologist 102(2) pp. 215-239).

So yes, Jason, this is a tricky genus to say the least!

It seems that P. wulfenioides is another corticolous species
By: zaca
2015-10-15 09:47:13 -05 (-0500)
Still no definitive answer…
By: J-Dar
2015-10-15 07:59:45 -05 (-0500)

But we are getting closer! I am not confident with my spot test results, so i’ll try them again and see what I get. P. lecanina should be KC- or Red, and I got goldish. And I got a yellowish for the C test, but it should be C- or Red for this species. One other species that comes up on the CNALH dynamic key for the region is P. wulfenioides, but there is no description available and I couldn’t find one online.

A note about the apothecia of this specimen, whether poriform or disciform, the disk color may be disguised by thick white pruina.

Good work J-Dar!
By: zaca
2015-10-15 05:28:19 -05 (-0500)

Of course I know nothing about N. A. species of Pertusaria, but I was reading a description of P. neolecanina, available at
and there are two itens that don’t match: 1) This species is corticolous; 2) The ostioles are said to be black and we can see in the close up that they are colourless or pale coloured.
So, if there are no other possibilities in the group of “poriform” species with 2-spored asci and with at least norstictic acid, maybe it is worth to consider “disciform” species, because as the apothecia are young it could happen that the development will lead to discioid apothecia.
As you live in a country where the checklists are “very” reliable, I hope you will find soon a name for it. Good luck.

Yikes, that is subtle
By: Jason Hollinger (jason)
2015-10-14 19:22:51 -05 (-0500)

I would have called that poriform for sure… and I did! But sure enough, there are no other good choices. Even in the world key. The only North American poriform species with thiophaninic and norstictic acids is P. neolecanina… which is close, but only if you speak Spanish… ;)

Tricky genus sometimes, isn’t it??

Microscopy added
By: J-Dar
2015-10-14 18:57:25 -05 (-0500)

Going with the asci being 2-spored and norstictic acid present, it seems we need to consider the apothecia as disciform, not poriform, which pretty easily takes us to P. lecanina. I have no experience with this distinction, however, so I added a detail photo of an apothecium. This species is correct for the locality.

One photo uploaded
By: J-Dar
2015-08-15 11:29:43 -05 (-0500)

of a spot test detail, but nothing that will provide anymore insight. There is so much going on with this piece of bark, at least one other Pertusaria, a sorediate one, one or more scripts, and other tiny things. The lichen variety and thallus overlap could cause spot test problems I would imagine. I’ll update this with a UV test next week. And…drum roll…a microscope might get ordered late next week…

Zaca knows what I think about spot tests…
By: Jason Hollinger (jason)
2015-08-14 23:19:17 -05 (-0500)

I don’t trust them unless I see them myself, haha! :)

I would bet this has norstictic acid (K+r immediately) and thiophaninic acid (C+y KC+ strong gold). This doesn’t look sorediate to me. This looks typical of the “poriform” warts of Pertusaria. There are three options in the Sonoran Flora:

P. neolecanina – was south of here
P. wulfenoides – way inland of here
P. rubefacta – looks common along CA coast

You will be able to verify this much more confidently with microscope: norstictic acid will produce needle-shaped crystals, and you should find 8-spored asci and K+ violet epihymenium. Also, if you have a UV lamp, thiophaninic acid should be strongly UV+ orange. Good one to test your lamp on: if you don’t see UV+o then get another lamp! (Do it in a dark room to be sure, naturally.)

(I just checked the world key: N. Amer., 8 spores, norstictic and thiophaninic acids = P. rubefacta. Note that arthothelin has same spot tests as thiophaninic acid, but all those are in S. Amer. or elsewhere.)

No, I think that the genus is …
By: zaca
2015-08-13 16:28:13 -05 (-0500)

Pertusaria, at least the part in the top right of your first photo, but I don’t know if there are mixed thalli.

Ok I’ll check tonight
By: J-Dar
2015-08-13 16:15:26 -05 (-0500)

and confirm spot tests, it was definitely K+R immediately on the “apothecioid” fruiting bodies. Thallus K+Y faded to burnt orange after a few minutes, as shown on photos. Maybe it is technically K+R? Or are you thinking a different genus?

I’m talking by heart,
By: zaca
2015-08-13 12:41:41 -05 (-0500)

but I do not remember any Pertusaria sp. with a K + dark orange reaction. Probably, instead you will find in the literature either K+ brownish (dirty brown) or K+ yellow to red.

From the description of the genus Pertusaria in CNALH:
By: zaca
2015-08-13 12:11:31 -05 (-0500)

“Ascomata: apothecioid, either sessile with an expanded, open disc or almost closed and perithecial like and one to several immersed within a wart; disc: sometimes covered with granular soredia and appearing soralia-like or pruinose;…”
Moreover, Pertusaria belongs to the class of Lecanoromycetes, thus their fruting bodies cannot be perithecia.

By: J-Dar
2015-08-13 11:29:27 -05 (-0500)

New to this genus, wasn’t sure what those structures were, but they seemed to have farinose soredia around the ostiole, are they perethecia? I’ll get some micro photos posted tonight hopefully. Thanks.

I don’t think this is Pertusaria amara;
By: zaca
2015-08-13 07:48:16 -05 (-0500)

At the top-right of the photo some ostioles are visible, meaning that the verrucas are fertile.

Created: 2015-08-12 22:06:23 -05 (-0500)
Last modified: 2015-10-31 10:19:07 -05 (-0500)
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