Observation 10114: Candelaria pacifica M. Westb. & Arup

When: 2008-08-25

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

Who: Jason Hollinger (jason)

Specimen available

microscopically fruticose lichen, on rough elm bark, probably enriched by bird droppings
THALLUS: bright yellow-orange, leprose to minutely subfruticose, very few lobes intact, undersurface quicky breaking up into granular soredia, lobes ascending
APOTHECIA: rare, lecanorine, orange, epihymenium brown, hymenium clear and IKI-, hypothecium clear, algae abundant under and in rims, paraphyses abundant and simple with rounded subclavate tips, asci clavate to balloon-shaped at maturity, thollus indented inside, thick IKI- wall and IKI- lens inside thollus that doesn’t seem to penetrate completely, cortex weakly K+ golden, epihymenium shows minute POL+ golden crystals/granules
SPORES: 8 per ascus, clear, 1 cell, oblong, smooth, IKI+ reddish, 12-16 × 3-5 µm Q=2.8-5.3 (N=10)

This is apparently a common species, that was until recently included in Candelaria concolor. However the soredia and number / size of spores clearly distinguish it.

In Pasadena, look for it just north of Heatherside on Linda Vista. It almost completely covers one of the trees on the west side of the street… but you have to be headed south to see it!


10x magnification.
30x magnification
Apothecial section, mounted in water, at 100×.
Apothecial section, mounted in water, at 400×.
Apothecial section, mounted in water, at 400×. Cortical pigments clearly visible in cross-polarized light!
Ascus, stained with Lugol’s, at 1000×. Shows thollus structure nicely.
Ascus and spores, stained with Lugol’s, at 1000×. Not very clear, but you get the idea — definitely fewer than 30 spores here!

Proposed Names

87% (1)
Eye3 Eyes3
Recognized by sight: soredia on lower surface
Used references: Nash’s Sonoran Flora
Based on microscopic features: spore number and size
Based on chemical features: weak K reaction

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Created: 2008-08-27 15:28:04 CDT (-0400)
Last modified: 2008-08-27 15:28:04 CDT (-0400)
Viewed: 309 times, last viewed: 2018-04-11 23:20:27 CDT (-0400)