Northwest Lichenologists
  • Home
  • Forum
  • P test color change in Hypogymnia?

P test color change in Hypogymnia?

  • 02 Sep 2025 7:34 PM
    Message # 13538153

    Would you consider the two samples in the attached photos P+R? To me both reactions look orange. The key (Macrolichens of PNW) asks if the reactions is either red or P-/weak yellow. 


    How red does it need to be to be considered P+R? Does a slow-to-emerge orange tinge count? Is there a technique to get a more distinct reaction?

    2 files
    Last modified: 02 Sep 2025 7:35 PM | Anonymous member
  • 03 Sep 2025 8:35 AM
    Reply # 13538348 on 13538153
    Anonymous member (Administrator)

    That's definitely the P+R from physodalic and protocetraric acids.

  • 03 Sep 2025 7:16 PM
    Reply # 13538602 on 13538153

    Okay thank you!

© Northwest Lichenologists

NWL Privacy Policy

Powered by Wild Apricot Membership Software