Observation 10115: Rinodina laevigata (Ach.) Malme
When: 2008-08-26
Herbarium specimen reported

Notes: crustose lichen, on bark of ash, in spray zone of sprinklers
THALLUS: light to medium gray-green, scabrid, dull, K-
APOTHECIA: lecanorine; disk black, matte, epruinose, flat to convex; rim gray-green like thallus, crenulate, barely raised, persistant, filled with algae, cortex thin and uniform; epihymenium brown due to paraphyses tips; hymenium clear; hypothecium clear; paraphyses simple, abruptly clavate, with brown caps
SPORES: clear then gray then dark brown, elliptical, smooth, 2 cells, 8 per ascus, uneven walls (apical thickening and angular septum when young, lumina inflating in age, sometimes forcing apical thickening to protrude as a snout, torus present and rarely swelling slightly in K), large round oil bubble usually present inside mature lunina, sometimes curved when young, 14-15 × 7-8 µm

Spore structure at various stages of development is critical for this genus, and difficult to learn. I’m pretty confident I’ve diagnosed this one correctly, though. This is a cosmopolitan species — which you would expect of a “lawn weed” like this.

Images

18782
Taken under dissecting scope, at 30×.
18781
That’s it just right of center, surrounded by the much more abundant Lecanora hagenii.
18783
Mature Physcia-type spores, mounted in water, at 1000×. Note the apical thickenings still present, ruling out Physconia-type spores.

Proposed Names

87% (1)
Eye3 Eyes3
Used references: Nash’s Sonoran Flora
Based on microscopic features: spore structure and development

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Eye3 = Observer’s choice
Eyes3 = Current consensus

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Created: 2008-08-27 21:53:02 CEST (+0200)
Last modified: 2008-08-27 21:53:21 CEST (+0200)
Viewed: 74 times, last viewed: 2016-03-20 21:55:27 CET (+0100)