Observation 87290: Lecanora strobilina group

When: 2012-02-01

Collection location: Davis, California, USA [Click for map]

Who: Byrain

No specimen available

Growing on a wooden fence, I suspect this may be the same as obs 70022 which is on a nearby fence. I don’t recall this patch yet existing then, but maybe I was somehow just missing it.

And there now appears to be apothecia present on some of it, I also redid the chemistry, K+ yellow, C+pale yellow, KC+ gold (usnic acid?), CK-.

Proposed Names

28% (1)
Recognized by sight
84% (1)
Recognized by sight: roughened thallus and poorly-formed irregular apothecial rims
Based on chemical features: KC+ gold

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
I see it now
By: Byrain
2012-02-01 18:53:23 CST (-0600)

Now that you so nicely laid it out, I can see how these are different, thanks. And the K test did clearly turn the thallus yellow, I would of taken a picture of it if I didn’t already have enough trouble getting the two pictures.

These are down the block from my house so I will collect some to work on later, I can barely see the apothecia as it is now.

I think this is different from observation 70022
By: Jason Hollinger (jason)
2012-02-01 18:13:22 CST (-0600)

That one is entirely granular-sorediate; this one is just sort of roughed-up verruculose. I’d say it’s in the Lecanora strobilina group. They all have usnic acid, plus sometimes xanthones (C+o and maybe slightly K+?). They are distinguished by the rough, poorly-formed apothecial rims and roughened thallus. Seen next to other Lecanora they have a distinctly yellowish-greenish cast to them, but in an individual photo like this, especially in the shade reflecting lots of blue sky, they can look downright blue-gray and not the slightest yellowish. Unfortunately, I can’t find any members of the group that would be true K+y. It is neat to see how well the KC+y turned out, but I’m still concerned about all the apparent false positives. There is clearly some acquired skill to reading these Q-tip tests!

I think the only way you’re going to get verification on this ID is to do a thin section of the apothecium and check for crystals above and below the hymenium, and check if they dissolve in KOH. Spore size can also help in verification.

Created: 2012-02-01 17:25:30 CST (-0600)
Last modified: 2012-02-01 18:14:01 CST (-0600)
Viewed: 34 times, last viewed: 2017-06-10 08:43:41 CDT (-0500)
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