Observation 270277: Lecanora Ach.

When: 2017-02-15

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

35.8234°N 120.296°W 450m [Click for map]

Who: J-Dar

Specimen available

Notes:
Specimen was collected from an old wooden ranch fence in a grassland setting along a willow/cottonwood riparian zone.

Thallus irregularly lumpy to areolate, greenish (from algae showing through) grey, K-, C-, P-. Apothecia generally crowded, 0.3-0.5mm, flexuose, lecanorine with dark reddish brown epruinose disks and prominent thalline margin concolorous or lighter than thallus, K-, C-, P-. Hymenium hyaline, hypothecium dingy. Amphithecium algae-filled, 20-25µm thick (width, adjacent to hymenium) with algae extending down beneath hypothecium. Amphithecium does not appear to have cortex at 100x, under dissecting scope the margin is speckled green where you can see the algae. Epihymenium light brown, partially clearing and darkening in K. Amphithecium with few small crystals and epihymenium with almost no small crystals, those present were soluable in K.

Spores 8/ascus, simple, ellipsoid, hyaline. Average size 11.7×5.8 (n=4)

Images

100x in water
100x in water with Polarizing filters
100x in water with K
100x in water with K. Note lack of POL+ crystals after K
Amphithecium detail at 400x in water

Proposed Names

28% (1)
Recognized by sight
20% (3)
Used references: B. Ryan key II-D of corticolous Lecanora: Corticolous/Lignicolous. Non-sorediate, Thallus +/- grayish, whitish, or immersed, K-; apothecial margins +/- grayish or whitish, K-; disks brownish, red-brown, or black.

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= Observer’s choice
= Current consensus

Comments

Add Comment
Same reservations
By: Jason Hollinger (jason)
2017-02-20 18:11:40 CST (-0500)

L. hagenii shouldn’t have a well-developed thallus. But what can this be?? My best guess is that we’re missing some chemistry because spot tests on Lecanora are really hard. I wonder if TLC would show presence of isousnic acid or minor amounts of atranorin…

ID discussion
By: J-Dar
2017-02-19 12:35:29 CST (-0500)

This seems to be closest to an epruinose variety of Lecanora hagenii. For various reasons it keys close to but is not quite right for Lecanora coniferarum, Lecanora flowersiana, Lecanora mughicola, and Lecanora zosterae.

Lecanora hagenii often has very pruinose discs, but this epruinose specimen seems to be within the uncommon variation of the species. I used Bruce Ryan’s key “II-D of corticolous Lecanora: Corticolous/Lignicolous. Non-sorediate, Thallus +/- grayish, whitish, or immersed, K-; apothecial margins +/- grayish or whitish, K-; disks brownish, red-brown, or black.”