When: 2017-02-19

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

35.4567°N 120.688°W 279m [Click for map]

Who: J-Dar

Specimen available

On sandstone in blue oak (Quercus douglasii) woodland.

Thallus scant, verruculose, whitish, K+Y. Effigurate, generally orbicular, prothallus lacking or whitish. Apothecia to 1.8mm, plane becoming convex, dark mohagany brown, entirely epruinose, with white thalline margin becoming reduced in age, margin K+Y. Hymenium and hypothecium hyaline. Epihymenium yellow-brown, with a thin line of small orange-ish POL+ crystals on the top. Crystals and epihymenial pigments not soluble in K. Amphithecium has small white crystals extending beneath apothecium, maybe in medulla tissue, and larger orange-ish crystals on the outer edge. The small crystals are soluble in K and the large crystals are not.

Spores 8/ascus, broadly ellipsoid, hyaline, simple. Average 13.2×7.8µm (n=4).


Polarized light. Note amphithecial crystals in bottom left photo, bottom right corner, not soluble in K. Also on epihymenium.

Proposed Names

28% (1)
Recognized by sight
61% (2)
Recognized by sight

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

= Observer’s choice
= Current consensus


Add Comment
Amphithecial crystals
By: J-Dar
2017-07-08 23:36:44 CDT (-0400)

Before I get ahead of myself, this observation is very near observation 265154, and I think is the same species.

This is something close to either Lecanora pseudistera or Lecanora campestris. Having never seen either, I’m at a loss.

Still trying to get calibrated with reading Lecanora crystals, small vs. large, soluble in K, etc. I’m seeing a thin line of crystals on top of the epihymenium, neither of these two species should have. So, I think it could be dust grains on the apothecia disk. The amphithecium shows two types of crystals, as described above. It seems to me there are insoluble large crystals after treatment with K, which would push this to L. pseudistera. There are no specimen records in CNALH in this area of California.

Created: 2017-07-08 23:24:20 CDT (-0400)
Last modified: 2017-07-08 23:37:57 CDT (-0400)
Viewed: 22 times, last viewed: 2019-08-20 14:14:52 CDT (-0400)
Show Log