Observation 109051: Xanthomendoza montana (L. Lindblom) Søchting, Kärnefelt & S. Kondr.
When: 2012-09-07
No herbarium specimen

Proposed Names

27% (1)
Recognized by sight
29% (1)
Eye3 Eyes3
Recognized by sight: Ubiquitous yellow orange lichen on trees in Utah. These however look to be parasitic on a grey green lichen, which looks like it might be killing the tree.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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For whatever it’s worth…
By: Jason Hollinger (jason)
2012-09-29 23:21:20 PDT (-0700)

Lichens can’t grow fast enough to compete with the needles toward the end of branches, which is where most photosynthesis takes place, I believe. Where you see abundant growth of lichens on branches and twigs like this, it’s typically near the ground where the branches are growing very slowly (because the tree is putting all its energy into growing much more productive foliage at the top of the tree where there are no lichens).

The total mass of lichens can be quite impressive, and it’s entirely possible that they contribute to trees falling in wind or snow storms, say. But they definitely do not parasitize the tree, and probably don’t interfering with photosynthesis significantly.

Also note that lichens fix appreciable quantities of nitrogen (this has been well-measured in a variety of forest types around the world), thereby helping fertilize the tree a little. And, hey, maybe they help insulate the branches and bark a little during severe winters?

Admittedly, I’m hardly unbiased in the matter, but I’m inclined to believe that lichens do little or no harm on the balance.

By: Danny Newman (myxomop)
2012-09-07 23:07:46 PDT (-0700)

to what in this photo are you referring?

Created: 2012-09-07 22:53:57 PDT (-0700)
Last modified: 2012-09-29 21:36:39 PDT (-0700)
Viewed: 81 times, last viewed: 2016-10-25 23:37:26 PDT (-0700)
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