When: 2018-01-07

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

35.5046°N 120.7162°W 381m [Click for map]

Who: J-Dar

Specimen available
Collection number: Jason Dart 895

On bark of Pinus sabiniana in an oak woodland habitat.

Individual thallii very small, <<1cm, consisting of a continuous irregularly shaped green-gray, K- crust. Apothecia are common, lecanorine, with thalline margins concolorous with thallus that become somewhat reduced and darkened.

Spores 8/ascus (one apothecia has consistently 4 spores), Type A development, Physcia-type with large apical and septal swellings, angular lumina, light torus. 1-septate, brown, broadly ellipsoid. Average size 14.4×7.6 (n=7).

Spore size is on the low end for Rinodina laevigata, but Sheard (Nash Sonoran Flora V2) says “The Californian population often has smaller spores with more persistently angular lumina and sometimes better developed thalli, that may be gray rather than pale brown…It may prove to be a separate taxon upon further study.”


400x in water, heated
400x in water, heated
400x in water, heated
100x in water
400x in water

Proposed Names

57% (1)
Based on microscopic features: Spore details

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= Observer’s choice
= Current consensus


Add Comment
Usually I don’t have to shrug that often!
By: Jason Hollinger (jason)
2018-01-09 13:19:03 PST (-0800)

What a strange specimen.

I was wondering if one of the lumina just didn’t develop?
By: J-Dar
2018-01-09 13:04:18 PST (-0800)

I looked at that spore an shrugged, figuring it was just some sort of defect. One apothecial section had only 4 spores in every ascus. Again, I just shrugged and figured it was just a defect of some sort.

By: Jason Hollinger (jason)
2018-01-09 12:36:55 PST (-0800)

One of the spores (just above dead center in last photo) shows apical thickenings but no septum — clear type-B development. Must just be a freak error. Nice photos!