When: 2017-11-24

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

35.4457°N 120.6333°W 268m [Click for map]

Who: J-Dar

Specimen available

On weathered redwood fence board.

Thallus not evident except maybe for a thin granular layer on top of the wood surface. Apothecia abundant, lecideine, convex, often aggregated. Hymenium and hypothecium hyaline, K/I+Blue, epihymenium black with blueish tints, K+Violet. Paraphyses much branched.

Asci broadly ellipsoid to globose, 8 spores? Tholus K/I+Blue. Spores 1-2 septate, bean shaped, 8×2.5µm.

Thallus of this one doesn’t seem to be well developed enough for Micarea denigrata. Could be Catillaria or Biatora?


Apothecia squash 100x in K
Apothecia squash K/I

Proposed Names

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Recognized by sight
57% (1)
Recognized by sight

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Add Comment
Good, yes, you’re looking for fine crystals
By: Jason Hollinger (jason)
2017-11-27 10:55:34 EST (-0500)

Sounds like there’s definitely none there.

Gyrophoric Acid
By: J-Dar
2017-11-27 10:00:46 EST (-0500)

Added C under the cover slip at 400x and didn’t get any C reaction to a section that included an apothecia and algae and whatever minor amounts of thallus material was there. Cross polarized (photo added) I didnt seem to get anything significant either. For gyrophoric detection under POL, is it crystals on in the thallus cortex that are diagnostic? Color?

Still need to look at pycnidia and see if I can find the stalked ones.

Nice ascus stain
By: Jason Hollinger (jason)
2017-11-25 00:22:10 EST (-0500)

The K+ purplish thing is common in Micarea. That’s what I’d go with, but maybe there are Catillaria or Biatora with the same reaction that I just don’t know about.

Note that C test is very subtle in Micarea. This is a great time to check for POL+ granules as a more sensitive indicator for gyrophoric acid in low concentrations.

Agreed that this is not M. denigrata. I wouldn’t completely rule out M. misella yet. Can you find pycnidia? I think I see some “stalked” ones in the photo. If so, that would help support M. misella despite some spores being septate. But I’ve never seen it with 2-septate spores. Maybe it’s this M. nitschkeana however it’s spelled…

Created: 2017-11-24 23:51:15 EST (-0500)
Last modified: 2018-06-23 13:48:44 EDT (-0400)
Viewed: 55 times, last viewed: 2018-12-16 21:49:03 EST (-0500)
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