Northwest Lichenologists

Phaeorrhiza sareptana

  • 13 Nov 2015 3:53 PM
    Message # 3632704

    Hi all,

    I thought I would share my Phaeorrhiza sareptana exploration. I have been finding it quite a bit in our MT steppe. In the Biotic Soil Crust book, it is in the brown sqaumule key, and P. nimbosa is mentioned being similar but often yellowish. Well, most all our specimens have been yellowish to greenish ochre, so I looked at the possibility of P. nimbosa. It was K+ violet though, so it was still P. sareptana. Not that this is a great indication, but I couldn’t find one photo that looked like ours on the web, even though the other characteristics fit P. sareptana. In looking, I did find that in the lichenportal site squamules were described as: “brown or paler to ocher or yellow-green in shade.” Aha! Photos are in the gallery, just for fun.

    Cheers!

    Last modified: 13 Nov 2015 3:54 PM | Rebecca Durham
  • 26 Nov 2015 3:57 PM
    Reply # 3662184 on 3632704
    Deleted user

    Hi Rebecca - I've found a few samples I'm calling Phaeorrhiza sareptana but they do not react KPurple in the lower medulla/rhizohyphal weft region (K- instead); in addition I get a distinct KY upper cortex response. Have you run across this?

  • 27 Nov 2015 3:42 PM
    Reply # 3663458 on 3632704

    Hi Diane,

    What you probably have is P. nimbosa. Often you can ID it because the whole thallus has a yellowish look. And I get that K+yell rx in the medulla. Bruce mentions it in his book under P sareptana. It is very common in parts of the PNW - I can't remember if it seems more common as you go N or S (in OR), I think the latter. Other places one doesn't find it at all.

    best, Daphne

  • 30 Nov 2015 8:48 AM
    Reply # 3667678 on 3632704

    Most of the samples that I found were very yellow. I didn't see a K reaction under the dissecting scope, but did see the purple reaction by flooding the slide with K and observing the thallus slice under the light microscope. So that suggested P. sareptana. I wonder if there are other characteristics that might separate the two superficially, or if I will need to check each one to see if they are K+ violet? 

  • 01 Dec 2015 3:43 PM
    Reply # 3669896 on 3632704

    I check each one. It isn't too hard, and even when I thought I could tell the two apart, I was wrong half the time.

    best, Daphne

  • 02 Dec 2015 7:32 AM
    Reply # 3670992 on 3632704

    Thanks Daphne, I will check each one. Good info!

  • 11 Jan 2016 11:49 AM
    Reply # 3752651 on 3632704

    I have found a number of P. nimbosa now. The superficial appearance of the thallus has not been indicative, as both are often quite yellow. I have been checking each for the K reaction, and have seen a slight K+Y in P. nimbosa.  I have found that I can ID which one is which by the medulla color alone: the white medulla in P. nimbosa is enough to distinguish it using a strong hand lens or dissecting scope. 

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