Observation 21730: Psora tuckermanii R. Anderson ex Timdal

When: 2009-05-28

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

Who: Jason Hollinger (jason)

Specimen available

Found mostly sterile on limestone in sheltered locations, but one thallus with apothecia (which from appearance at 30x and chemistry I’m inferring to be the same thing) growing among Psora himalayana on mossy exposed rock.

SQUAMULES more ascending than usual and overlapping somewhat, K-, C-, KC-
APOTHECIA reddish-brown, plane when very young, very soon becoming convex and emarginate
EPIHYMENIUM brown, K+ red, POL+ bright red-brown
HYPOTHECIUM reddish-brown, POL+ bright red-brown, K-?
SPORES 8 per ascus, simple, hyaline, smooth, elliptical, 9.7-14 × 6.3-7.9 µm (Q=1.3-1.8 — averaging 1.6) (N=18)

This keys out more convincingly as Psora pseudorussellii however that species doesn’t belong anywhere near here:

name avg Q apothecia distribution
P. tuckermanii 1.36 brown, always? convex and emarginate western
P. pseudorussellii 1.67 red-brown, flat and marginate at first eastern and southern

Interesting. But frustrating.


sterile one
young apothecia
Apothecial section in water at 100×.

Proposed Names

58% (1)
Eye3 Eyes3
Used references: Lichen Flora of the Greater Sonoran Region, Lichens of North America
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 17:54:27 CDT (-0400)
Last modified: 2009-06-05 17:54:27 CDT (-0400)
Viewed: 177 times, last viewed: 2018-04-12 10:47:27 CDT (-0400)
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