Northwest Lichenologists

Umbilicaria virginis

  • 03 Feb 2015 4:26 PM
    Message # 3217215
    Has anyone ever seen orange color on the underside of U. virginis before?
    I am wondering if the color is from something in the lichen, or I suppose
    it could be iron from the basalt it was attached to leaching out.
     
    Either way I have never seen color like that in an Umbilicaria.

    I have posted pictures in an album.

    Picture 1

    Picture 2



    Last modified: 03 Feb 2015 4:47 PM | Steve Sheehy
  • 05 Feb 2015 7:37 PM
    Reply # 3218906 on 3217215
    Bruce McCune (Administrator)

    I don't recall seeing that before, Steve, although it is common to see rust-colored stains in various lichens, when in contact with iron-containing minerals. Yellow and orange colors produced by lichens are usually anthraquinones, which react K+ red. I wouldn't expect an stain from the rock to react that way.

    Bruce

  • 05 Feb 2015 10:51 PM
    Reply # 3218989 on 3217215

    I tried the K test, the orange area did turn red. Are anthraquinones common in Umbilicaria species?

  • 06 Feb 2015 8:13 AM
    Reply # 3219264 on 3217215
    Bruce McCune (Administrator)

    Nope. But then there is the famous Umbilicaria phaea var. coccinea. Has anyone tested that red pigment to see if it is K+ stronger red?

  • 06 Feb 2015 1:21 PM
    Reply # 3219612 on 3217215

    The medulla of Umbilicaria phaea var. coccinea is K-, however the upper cortex is K+ very dark purple to almost black. U. phaea upper cortex is K-.

  • 27 Feb 2015 8:25 PM
    Reply # 3237626 on 3217215
    Anonymous
    Hello-


    Interesting discussion, relating to red pigments in Umbilicaria, you might want to check out Grube et al. 1995. There is a brief discussion/speculation of a parasitic Arthonia "inducing" a red pigment defensive response in the host Umbilicaria. 


    Grube, M., M. Matzer, J. Hafellner. 1995: A preliminary account of the lichenicolous Arthonia species with reddish, K+ reactive pigments. - Lichenologist 27(1): 25-42


    -JV

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