Observation 208873: Caloplaca cerina group

When: 2015-07-04

Collection location: Stadium Park, Atascadero, California, USA [Click for map]

35.4913° -120.6627° 271m

Who: J-Dar

Specimen available

Thallus dark grey, well-developed, something like verruculose, apothecia slightly stipitate, disc orange, thalline margin lighter than thallus, raised, epihymenium K+R (blood red), margin K-, C-, KC-, thallus K-, C-, KC- (Thallus and epihymenium supposed to be K+Violet).

Proposed Names

31% (2)
Recognized by sight
56% (1)
Recognized by sight
28% (1)
Recognized by sight

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
That’s an interesting idea
By: Jason Hollinger (jason)
2015-07-05 15:36:14 PDT (-0700)

You might try checking sorediate species just in case.

Zaca, sorry, I don’t really understand Portuguese, I was just guessing based on limited Spanish!

Couple things
By: J-Dar
2015-07-05 15:29:37 PDT (-0700)

The largest apothecia might be up to 0.8mm in diameter, but they are frequently smaller.
The thallus actually looks to be uniform light gray, and there is something dark and granular on top of it, maybe a parasite? Sort of looks like soredia with a few isidioid things…see that granular texture between the apothecia in the micro shots? But at 40x, it is impossible to get any more detail.

You can find info about C. cerinella at
By: zaca
2015-07-05 15:03:45 PDT (-0700)

British Flora, pages 256-7., but I noticed now that the apothecia are tiny (1/5 of those of C. cerina).

Never heard of C. cerinella!
By: Jason Hollinger (jason)
2015-07-05 14:39:34 PDT (-0700)

Seems to be a great deal of confusion surrounding it, too: is it on rock or on bark, for example? Authorities differ! But it’s polysporous, that should be distinctive, at least… when you get your scope! :)

While waiting for the compound scope …
By: zaca
2015-07-05 14:24:47 PDT (-0700)

why not C. cerinella. As far as I understand the chemistry agrees on this one.

It might not help with this one
By: Jason Hollinger (jason)
2015-07-05 13:17:20 PDT (-0700)

Don’t remember if there are any significant microscopical differences. Just worth getting as much info as possible before making a decision!

I’ll keep the specimen
By: J-Dar
2015-07-05 13:14:32 PDT (-0700)

I swear I’ll pick up a compound scope some time soon!
Thanks for the analysis.

In good material, the differences between
By: Jason Hollinger (jason)
2015-07-05 13:09:28 PDT (-0700)

C. cerina, C. stanfordensis and C. pyracea (called C. holocarpa in Sonoran Flora) are “good”. It’s these marginal cases that are tough. With spore size and other characters we might be able to support one name over the others a bit more confidently. As it is, it just “looks weird” to me. :( I recommend leaving it at C. cerina group in the meantime.

Good point
By: J-Dar
2015-07-05 12:33:35 PDT (-0700)

So the orangish tinge on the inner side of the apothecial margin could be a “proper” margin concolorous with the disc? I can see that. C. stanfordensis looks pretty good, but a little off as you say. That split in the key is difficult, “thallus well developed, all gray” or “Thallus poorly developed or with some orange places or absent”. Leaves a lot of room for subjective interpretation!
I think C. stanfordensis may be a better determination than C. cerina, based on this comment by Nash in regards to the former: “It has often been called C. cerina but that species has dark gray apothecial margins…” This specimen definitely does not have dark grey margins.
Thanks for the reference to Wetmore 2007, I haven’t found it online yet but my subscription to the Bryologist should be coming soon!

Bluish-gray thing…
By: Jason Hollinger (jason)
2015-07-05 11:45:48 PDT (-0700)

Hard to say. Looks too small for Ochrolechia. I’d guess Lecanora until I had a chance to do a C test on it.

Nice photos
By: Jason Hollinger (jason)
2015-07-05 11:43:57 PDT (-0700)

It looks very much like there is some orange pigment on the rims, not just the disk. You might want to consider Caloplaca stanfordensis. That doesn’t look quite right, either, though.

Also, see photos on pg. 805 of Wetmore. 2007. Notes on Caloplaca cerina in North and Central America. The Bryologist 110(4): 798-807.

Nash describes
By: J-Dar
2015-07-05 11:33:30 PDT (-0700)

the apothecia margin as concolorous with thallus, but this and several other photos online show it much lighter. Did you mean the apothecia seem unusually pale in color?

Side note, do you think that is an Ochrolechia next to it, the blue grey thing?

This seems unusually pale
By: Jason Hollinger (jason)
2015-07-05 10:24:12 PDT (-0700)

But the spot tests clearly indicate C. cerina. Note, you will not see the K+ violet/mauve reaction in a macroscopic spot test. You really need to test it on a section under a microscope. And even then, the reaction is often weak or lacking. This species is widely considered to be an unresolved group hiding probably multiple taxa, I think.

Created: 2015-07-04 19:29:11 PDT (-0700)
Last modified: 2015-07-05 13:13:09 PDT (-0700)
Viewed: 83 times, last viewed: 2017-07-18 18:58:56 PDT (-0700)
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