When: 2014-06-01

Collection location: Lincoln Trail State Park, Illinois, USA [Click for map]

Who: Terri Clements/Donna Fulton (pinonbistro)

No specimen available


Proposed Names

18% (2)
Recognized by sight: Gray green foliose lichen up to 4 cm across, buff on under surface. Numerous isidia, no discs. Upper surface covered in white “pimples”. On maple.
Abundant in this area.
-1% (2)
Used references: Brodo, Lichens of North America

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= Observer’s choice
= Current consensus


Add Comment
Parmelia is extremely close
By: Jason Hollinger (jason)
2014-06-09 00:21:06 EDT (-0400)

Both have pseudocyphellae and the same lobe structure and particularly abundant atranorin (more blue than the average “parmelioid” lichen). The biggest difference is that the pseudocyphellae are dots on Punctelia (“punctate”, thus the name), while they are irregular and linear on Parmelia. There are very few Punctelia out west, maybe none in the west northwest. But they are abundant and diverse in the midwest and east.

Thanks, Jason.
By: Daniel B. Wheeler (Tuberale)
2014-06-08 23:45:37 EDT (-0400)

I was hard pressed to provide anything for this obs. Illinois does not seem to be the center of lichenology.

Apologies, Terri/Donna. In my defense, many Punctelia also have Parmelia synonyms. Not many Parmelia in IL. though.

I’m still considering P. rudecta
By: Jason Hollinger (jason)
2014-06-08 22:45:45 EDT (-0400)

The difference is just the coarseness of the isidia. P. rudecta has tiny, fine, shiny-tipped isidia, many per dot. P. missouriensis has coarse, dull-tipped almost sorediose or “squamiform” “isidia”, only a few per dot.

The colors are actually pretty good, the way I see it. The third photo is a close-up near the tip, where you can see the same greenish tint in the top photo. This amount of variation is all perfectly within the lichen’s rights. It won’t produce its full complement of atranorin (sunscreen pigment giving it the bluish tint) until older, thus the growing margins are greener. Especially if damp at all.

It takes a great deal of experience to learn what constitutes “acceptable” variation and what constitutes taxonomic differences. Many lichen pigments are variable within the same thallus, or even depending on the time of year(!) Based on light, moisture, minerals, lots of things.

Thanks, Jason
By: Terri Clements/Donna Fulton (pinonbistro)
2014-06-08 22:44:28 EDT (-0400)
Colors off in photos
By: Terri Clements/Donna Fulton (pinonbistro)
2014-06-08 22:15:52 EDT (-0400)

due to shadows/lack of light on some areas. I believe they are all the same. The true color as I described it is a gray green color.


Mixed collection?
By: Daniel B. Wheeler (Tuberale)
2014-06-08 22:04:36 EDT (-0400)

The first photo appears to be a bluish-gray lichen. The second may be a close-up of the third. The third photo is a Granny Smith apple-green lichen, and does not seem to be the same thing as the other photos. Am I wrong?