Observation 13046: Umbilicaria phaea Tuck.

When: 2007-02-21

Collection location: Little McClellan Rock, Humboldt Co., California, USA [Click for map]

Who: Jason Hollinger (jason)

Specimen available


Apothecia, at 30×.
Apothecia, at 30×.
Underside at 30×.

Proposed Names

-29% (1)
Recognized by sight: raised circular gyrose black apothecia, black rugose-papillose below
Based on chemical features: medulla C+ red
87% (1)
Recognized by sight

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= Observer’s choice
= Current consensus


Add Comment
There seem to be two forms of U. phaea
By: Jason Hollinger (jason)
2009-08-26 07:23:28 +07 (+0700)

Going through my old observations, I just noticed this thing. It is clearly U. phaea — shiny, smooth, brown upper surface; coarsely grainy, non-sooty lower surface without any plates or rhizines; copious gyrose apothecia. However, this one has round apothecia that sit on top of the surface, as compared to the much more common form that has irregular, angular apothecia that are sunken into the surface, at least to some degree.

I was giving it an ID of U. hyperborea based on Irwin Brodo’s Lichens of North America. He distinguishes the two species in the notes of U. phaea: “U hyperborea has a more verrucose upper surface and rounder, superficial apothecia”. However, I find that I have to agree with Trevor Goward in this matter. He emphasizes the texture of the upper surface over the disposition of the apothecia. While U. hyperborea is admittedly an extremely variable species with respect to degree of verrucation and overall color, I’ve never seen it even approach smooth and shiny as this specimen is.

The third possibility is, of course, that this is an undescribed species… (Not as laughable as one might think.)

Created: 2008-10-24 04:17:49 06 (0600)
Last modified: 2008-10-24 04:17:49 06 (0600)
Viewed: 39 times, last viewed: 2019-01-24 02:41:31 06 (0600)
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