Lichen Placopsis gelida

ralfwagner · Post by **ralfwagner** » Wed Sep 26, 2018 7:24 am

Hello,

this lichen was found by my wife during her Iceland holiday. Location was near Selfoss, substrate was lava.
Placopsis gelida is a crustose lichen, characterized by pale orange cephalodia in the center of the thallus. Cephalodia contain a second photobiont, in this case the cyanobacterium Stigonema. The other photobiont, situated in the lobes, is a coccoid green algae.

Closeup thallus:

Section cephalodium:

Section lobe, LCB stain:

Section cephalodium, darkfield:

Section cephalodium, polarized light:

Lou Jost · Post by **Lou Jost** » Wed Sep 26, 2018 7:27 am

Very nice. How do you get them off the substrate without breaking them?

Jacek · Post by **Jacek** » Wed Sep 26, 2018 10:28 am

Very nice

vasselle · Post by **vasselle** » Wed Sep 26, 2018 11:18 am

Bonjour
Very nice
Cordialement seb

ralfwagner · Post by **ralfwagner** » Thu Sep 27, 2018 10:30 am

Hello and thanks @all!

Lou, I was using a scalpell. It is popssible cut off small pieces that are suitable for a section, aprox. 2 or 3 mm in diameter.

WalterD · Post by **WalterD** » Sat Sep 29, 2018 1:28 pm

Beautiful! Both in- and outside.

ralfwagner · Post by **ralfwagner** » Sun Sep 30, 2018 10:16 am

Thank you, Walter.

Smokedaddy · Post by **Smokedaddy** » Sun Sep 30, 2018 12:39 pm

Excellent

ralfwagner · Post by **ralfwagner** » Tue Oct 02, 2018 3:54 am

Thank you, smokedaddy.

ChrisR · Post by **ChrisR** » Tue Oct 02, 2018 4:14 am

Beautifully done, as always Ralf.

BJ · Post by BJ » Tue Oct 02, 2018 9:56 am

Ralf,

as usual great images. Your series of lichen photos are always superb.

Thank you for posting,

regards,

brianO

ralfwagner · Post by **ralfwagner** » Wed Oct 03, 2018 7:12 am

Thank you for your kind comments, Chris and Brian.

RogelioMoreno · Post by **RogelioMoreno** » Wed Oct 03, 2018 9:19 am

Nice!

Rogelio

JH · Post by JH » Wed Oct 03, 2018 9:41 am

Interesting photos and inspiring!
Best regards
Jörgen Hellberg

ralfwagner · Post by **ralfwagner** » Fri Oct 05, 2018 7:14 am

Thank you, Jörgen.