Observation 96879: Umbilicaria americana Poelt & T. Nash

When: 2012-06-04

Collection location: Cheney Wetland Trail, Spokane Co., Washington, USA [Click for map]

Who: nastassja (Nastassja Noell)

Specimen available

Substrate: Columnar basaltic rock, about 5-8 feet above soil line.

Habitat: Along channels of scablands, wetlands nearby, meadow, Ponderosa pine community.

Description: Smooth White-gray upper cortex, slightly pruinose. No apothecia or pycnidia or perithecia seen. Lower cortex black, densely rhizinate. Rhizines singular, tapering towards the end, many are somewhat club shaped; 500um-1200um long, 100-250um thick. Rhizines appear to be covered in brown multicellular thalloconidia (see photos).

( I’m not sure if these are thalloconidia on the rhizines, and if so, how to read them properly, but I determined the possibility that these are thalloconidia from photos of such here: )


Copyright © 2012 tim parker
Copyright © 2012 tim parker
Copyright © 2012 tim parker
watercolor and ink.

Proposed Names

12% (2)
Used references: Goward “Lichens of British Columbia”
McCune “Macrolichens of the PCNW
Based on microscopic features: Appears to be multicellular thalloconidia, particularly along rhizines.
Based on chemical features: Medulla: C+red. K- (muddy)

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Much gratitude Jason :)
By: nastassja (Nastassja Noell)
2012-06-10 00:47:24 CDT (-0400)

This one definitely doesn’t have the branched white rhizines like U. vellea, and location is certainly not alpine :) U. americana seems great fit.

By: Jason Hollinger (jason)
2012-06-10 00:20:43 CDT (-0400)

U. americana has all black, long, sometimes branching rhizines, U. vellea has a mixture of these rhizines (though often pale-tipped) and ball-tipped stubby rhizines. U. vellea tends to be alpine.

(Never looked at the thalloconidia before, thanks!)

Created: 2012-06-09 22:27:17 CDT (-0400)
Last modified: 2012-06-10 00:29:50 CDT (-0400)
Viewed: 357 times, last viewed: 2018-11-28 07:29:46 CST (-0500)
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