Observation 21728: Acarospora glaucocarpa (Ach.) Körber

When: 2009-05-28

Collection location: Vavenby Limestone South, British Columbia, Canada [Click for map]

Who: Jason Hollinger (jason)

Specimen available

Growing almost exclusively on/among Placynthium nigrum on limestone. (The stipe of the squamules appeared to go all the way through to the substrate, so perhaps the Placynthium grew up around it instead of vice versa?)

EPIHYMENIUM brownish, K-, C-, KC-, POL-
HYPOTHECIUM colorless but opaque and POL+ white (due to calcium oxalate crystals?)
PARAPHYSES strongly conglutinated at the tips even in K
SPORES many per ascus, hyaline, oblong, 3.4-4.0 × 1.3-2.5 µm (N=6)


This thallus is being parasitized by Acarospora glaucocarpa. The actual apothecia as it turns out are much smaller than the squamules of the acarospora.
Apothecium section in water at 100×. Shows the uneven, discontinuous algal layer below the apothecia — an important diagnostic character for this species.

Proposed Names

89% (2)
Eye3 Eyes3
Used references: Lichen Flora of the Greater Sonoran Region, confirmed by Curtis Bjork (although he said his specimens look a bit unusual for the species — the squamules should be reduced to just a lecanorine-like rim around the apothecia, there should be few if any lobed squamules)
Based on microscopic features
Based on chemical features

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Created: 2009-06-05 14:43:35 PDT (-0700)
Last modified: 2014-03-24 14:01:32 PDT (-0700)
Viewed: 121 times, last viewed: 2018-02-09 09:54:26 PST (-0800)
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