Observation 10255: Caloplaca arizonica H. Magn.

When: 2008-06-24

Collection location: Juniper Mountains, Yavapai Co., Arizona, USA [Click for map]

Who: Jason Hollinger (jason)

Specimen available

crustose lichen, on sheltered juniper bark
THALLUS: areolate, pale yellow, K- (or very weakly reddish), C-
APOTHECIA: dark orange; rims thalline but often with pigment bleeding over from discs; epihymenium and cortical pigments K+ blood red, C+ red, POL+ golden, soluble in K; hymenium IKI+ blue; paraphyses branched near tips, last 2-3 cells inflated
SPORES: 8 per ascus, polarilocular, 13+/-2 × 6.5/-1.2 µm (Q=2.0/-0.3) (N=15), septum 4.1+/-0.8 µm thick

This was quite common in the area. Color of the thallus varies anywhere from bone-white to lemon yellow to slightly orangish yellow. Color of the apothecia varies from bright orange to dark orange to almost brown. Treatment in Nash calls it “dark reddish orange”, and claims thallus should be K+ red, but I did not find this to be true. It is possible the pigment bleaches out of the thallus with exposure.


10x magnification
30x magnification
10x magnification
30x magnification
Apothecial section, in water, at 100×.
Apothecial section, in water, at 100x, in cross-polarized light.
Apothecial section, reacting nicely in KOH, at 100×.

Proposed Names

87% (1)
Eye3 Eyes3
Used references: Nash’s Sonoran Flora

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Created: 2008-08-31 14:52:59 CDT (-0400)
Last modified: 2008-08-31 14:52:59 CDT (-0400)
Viewed: 36 times, last viewed: 2017-06-05 02:35:16 CDT (-0400)