When: 2016-03-23

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

35.8841°N 120.3449°W 521m [Click for map]

Who: J-Dar

Specimen available

On intruded siliceous rock in full sun, semi-arid grassland habitat, with Aspicilia, Caloplaca, Lobothallia etc.

Thallii are tiny, up to 1cm in diameter, orbicular. Thallus is light grey, pruinose, cracked into angular areoles, medulla white, all tissue K-. Apothecia lecideine, without algae in margin, but the apothecia originate within the thallus tissue and have a “thalline collar” initially. Disk is black, flat. Epihymenium appeared black at 400x, but is described as brown. Hymenium hyaline, IKI+Blue dark and persistent. Hypothecium reddish brown.

Spores 8 per ascus, becoming brown, submuriform with 5-9 cells, measurements of 2 spores were 13.9×8.7µm and 17.3×8.5µm.


Apothecial section under dissecting scope showing algae in thallus tissue surrounding the apothecia
Apothecial section
Submuriform spores

Proposed Names

61% (2)
Based on microscopic features: submuriform spores

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= Observer’s choice
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Add Comment
Doesn’t look like many photos online
By: J-Dar
2016-06-25 12:49:06 CDT (-0500)

due to the distinctly separated angular areoles, and the deeply set apothecia that don’t seem to become superficial. The thallii are consistently tiny, fighting for space with Aspicilia species. I’ll have to look around to see if there are more or differently developed specimens in the area.

Looking different from …
By: zaca
2016-06-25 12:43:58 CDT (-0500)

what I’m used to observe (either in bark or in rock), I see no other alternative.