#ricasolia

[wild-e-eep]

A few photos of Ricasolia virens - one of my favourite lichens. ^_^

When well hydrated it is rampantly vogon-green, with a fishy odour, and exuding tiny droplets of a milky white fluid from its pimple-shaped pycnidia.

Also, <3 apothecia <3

iNaturalist observation 265204024

[wild-e-eep]

A very splendid Ricasolia virens lichen with a black, bushy thallus containing cyanobacteria and a scattering of bright green lobes with algae instead.

[wild-e-eep]

A good stick! :3

I went to Glen Shira last week - it's a special place for lichens. Every tree was clad in a bewildering array of colours and textures.

[wild-e-eep]

Ricasolia virens happens to be two of my faviourite lichens.

Here is Ricasolia virens - a small, bushy, cushion-forming jelly lichen:

But… This is also Ricasolia virens - a large, strikingly green, foliose lichen.

Both of these lichens are formed from the same species of fungus; the reason they look so different is because of the photosynthetic partner. The fungus forms a jelly lichen when it partners with a cyanobacterium, and grows broad, flat lobes when it partners with an alga.

Sometimes you can find a lichen with both photobionts on the same thallus - this can be called a photosymbiodeme. Here is a Ricasolia virens photosymbiodeme:

Related phenomena occur with Sticta canariensis:

and Ricasolia amplissima.

A slight complication: the word cephalodium can also be used to describe a lichen with algae and cyanobacteria both present, but it only allows for cases where the cyanobacteria are kept in small, subsidiary structures within or budding off of a primary algal thallus.

You can read much more about Ricasolia virens and its forms in this 2016 paper: The cyanomorph of Ricasolia virens comb. nov. (Lobariaceae, lichenized Ascomycetes) By Tønsberg, Blom, Goffinet, Holtan-Hartwig & Lindblom https://doi.org/10.5962/p.386096

[wild-e-eep]

Now that you mention it, there is something of the green man about this particular patch of lichen...

[wild-e-eep]

Giant candlewax lichen - Ricasolia amplissima - looking lush in this mild, wet winter weather.

I love it for its green, waxy lobes -

...but also for the brown, bushy cephalodia which have a translucent, remarkably jelly lichen-like quality.

iNaturalist observation 246392712