Northwest Lichenologists

another identification question

  • 08 Jun 2018 9:32 AM
    Message # 6298575

    See posted photos - crust on mossy Si rock, 520m elevation, relatively shady 2nd growth forest (western hemlock, red alder), Granite Creek trail, off Middle Fork Snoqualmie River. Green centers of bumps, (up to about 0.2mm across including “rim”), are masses of algae.

    Last modified: 08 Jun 2018 9:42 AM | Richard Droker
  • 09 Jun 2018 7:14 AM
    Reply # 6300449 on 6298575
    Bruce McCune (Administrator)

    I think you are saying that the things that look like lecanorine apothecia are actually thallus areoles... if so, this is a good puzzle. A number of genera including Lecidea, Miriquidica, and Rhizocarpon have species that make areoles with pale rims, but those generally have areoles are brownish or grayish. I think this must be a moist lichen, in which case the color might be deceptively green.


    The ellipse of dark objects is puzzling too. Is that a parasite?

  • 12 Jun 2018 6:31 AM
    Reply # 6305366 on 6298575

    Should have included more information - multiple protrusions/areole (see additional photos posted), concave on top each holding unstructured mass of algae about 75-150µm diameter, (although many apparently eroded off, perhaps by my handling, leaving depressions). Unfortunately no apothecia. Thallus both K and C negative. Looks like identification not possible.


    Don't think dark objects are parasite.


    (Looking more closely at the specimen rock I’m not sure that it isn’t calcic. Don’t have HCl and vinegar was negative. Limestone and marble not common in this area.)



    Last modified: 12 Jun 2018 7:19 AM | Richard Droker
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