Lair of the Hoverfly

 Fencepost of the Week #259

 A fearsome predator lurks in the lichens! This striking creature is the larva of a hoverfly. It mostly eats aphids.

Epistrophe grossulariae 

 

A Rusty Crescent

Fencepost of the Week #258 

Little Shaggy Moss

Fencepost of the Week #257
 

 Little shaggy moss - Rhytidiadelphus loreus - adding an impressive amount of volume to the top of this post.

 

Tongue and Groove

Fencepost of the Week #256
 

Stereocaulon Post

 Fencepost of the Week #255

 A soggy wooden post with a rather unusual topping: Stereocaulon dactylophyllum, I think.

 

 

Hanging Around

 Fencepost of the Week #254

 

 

Gigha Woodland Lichens

Lichen list from a visit to Southern Gigha on 8th December 2025

in roughly chronological order

-Leim Farm:
Physconia distorta - https://www.inaturalist.org/observations/329966449
Physcia tenella
Physcia adscendens - https://www.inaturalist.org/observations/330941598
Physcia leptalea? - https://www.inaturalist.org/observations/329966986
Ramalina farinacea
Ramalina fraxinea
Ramalina calicaris
Xanthoria parietina

-Into the mature trees:
Parmotrema perlatum
Anisomeridium sp? - https://www.inaturalist.org/observations/330943560
Peltigera hymenina
Normandina pulchella - https://www.inaturalist.org/observations/330941515
Coenogonium luteum - https://www.inaturalist.org/observations/330941517
Punctelia reddenda - https://www.inaturalist.org/observations/329969734
Flavoparmelia caperata
Melanelixia glabratula
Opegrapha vulgata - https://www.inaturalist.org/observations/330941036
Enterographa sp. (probably E. crassa) - https://www.inaturalist.org/observations/329970533
Pyrenula macrospora - https://www.inaturalist.org/observations/329970742
________
-Achamore, by the car park
Lobaria pulmonaria
Sticta limbata - https://www.inaturalist.org/observations/329973340
Parmotrema crinitum - https://www.inaturalist.org/observations/329973435
Usnea with bright red stems - suggestive of U. rubicunda, but it was probably decomposing Usnea cornuta s. lat. - https://www.inaturalist.org/observations/329974367
________
After lunch: 
- on stone wall
Peltigera praetextata
Peltigera membranacia
Lichenomphalia ericetorum - https://www.inaturalist.org/observations/329981229
- in boggy, newly planted woods
Sticta limbata
Sticta fuliginosa s. lat. (probably S. ciliata) - https://www.inaturalist.org/observations/329981661
Parmotrema perlatum
Parmotrema crinitum
Hypotrachyna laevigata
Lobaria pulmonaria
Lobarina scrobiculata
_______
-Shoreline, waiting for ferry
Scytinium gelatinosum 
Polychidium muscicola

Mouldering in a Gloomy Spot

 Fencepost of the Week #253

 

 

 

 

Roll-up

 Fencepost of the Week #252

 This entire fence has been pulled out of the ground and rolled up. It's still providing fertile surfaces for some nice lichens and mosses, though.

 

Grizzled and Cracked

 Fencepost of the Week #251

 

 

Cavernous Crater at Dusk

 Fencepost of the Week #250

 

 

Ricasolia virens - Cyanomorph, Chloromorph and Photosymbiodeme

Some lichenised fungi are capable of associating with both cyanobacteria and algae as photosynthetic partners. In some cases the appearance of the lichen changes very dramatically depending on which photobiont is present.

Ricasolia virens - cyanomorph

For example, here is Ricasolia virens - a small, bushy, cushion-forming jelly lichen. A cyanobacterium is the photobiont here.

But... This is also Ricasolia virens - a large, strikingly green, foliose lichen. This one has an alga as the photobiont:

Ricasolia virens - chloromorph

You can call the cyanobacterium containing lichen a cyanomorph and the alga containing lichen a chloromorph. 

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

Ricasolia virens - photosymbiodeme

Related phenomena occur with Sticta canariensis and Ricasolia amplissima.

Sticta canariensis - photosymbiodeme

Ricasolia amplissima - photosymbiodeme

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 chloromorphic 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

Diversity in Black and Green

 Fencepost of the Week #249

 A beguiling assemblage of lichens on this post betwixt field and forest.

 

Crowned in Sticta

 Fencepost of the Week #248

 Sticta sylvatica thriving in a damp, shady corner of the paddock.

 

Bilberry Webs

 Fencepost of the Week #247

 

Minutely Fruticose Jelly Lichens

 Trying to make sense of some superficially minutely fruticose, corticolous jelly lichens in Cowal. 

Working primarily from the BLS Lichens of Great Britain and Ireland 3 pdfs

 

Row 1 entire organism

Row 2 surface structure (width ~3mm)

Row 3 cross section from near substrate (bottom left) to surface (top right)

Row 4  cells of the cortex (width ~150µm)

Column 1: this is Scytinium lichenoides with well developed isidia, I think. 

Column 2: Scytinium teretiusculum ?

Column 3: Ricasolia virens cyanomorph ?

Column 4: Ricasolia amplissima cephalodium

 

I recently found a paper describing a cyanomorph of Ricasolia virens. Column 3 conforms very closely to the description given here: The cyanomorph of Ricasolia virens comb. nov. (Lobariaceae, lichenized Ascomycetes) DOI: 10.5962/p.386096

Now updated with a specimen of what I think is Scytinium teretiusculum; which I found for the first time in November. 

 Other similar things: 

Polychidium muscicola and Scytinium pulvinatum - I've only found these in saxicolous situations.  

I believe have yet to find Leptogidium dendriscum or a pure cyanomorph of Ricasolia amplissima both of which would fit into this category. Will keep looking.

Upland Post

 Fencepost of the Week #246

 Lichens in abundance on this upland post.

 

Billowing Green Moss

 Fencepost of the Week #245

 

 

Glenan Boulder Project

Aim: to track changes in lichen & bryophyte coverage on several boulders in the Glenan nature reserve over the years.

We propose to use photogrammetry to scan selected rocks anually; successive scans will be combined to produce 2d / 3d animations depicting the changes in vegetation cover over time.

 Meet the rocks:

Archie: One of the few places on the reserve where Ricasolia virens grows. Also with some Lobarina scrobiculata mixed in.

 

 

Brad: Right next to the path, just inside the woods. Brad has Nephroma laveigatum and patchy moss coverage. A small holly tree stands beside them, and there is a substantial void beneath.

 

 

Chuck: On flat ground, away from the the cliffs. Chuck has good bryophyte coverage - a lot of tamarisk moss on top (and drifting oak leaves), but also some leafy liverworts round the sides.

 

 

Doug: well up in a jumble of coarse talus, Doug is multifaceted - including some overhaging surfaces.

 

 

 

Ernest: a steep, roof-wise rock; less mossy than most of thier peers.

 

 

 

 

Frank: with a well-defined border of flat, leaf litter all around; Frank is a massive boulder with four sides - each with a different pattern of moss, lichen and liverwort coverage.

 

 

 

Greg: a fairly small, low boulder, almost completely covered in tamarisk moss, with some over-growing honeysuckle. 

 

 

Hugh: in a broad field of similar rocks; in the shade of the wide, spreading boughs of large oak.

 

Ivor: has a good variety of bryophytes - including some haircap moss, but also some small tufts of grass showing. Perhaps Ivor is on their way to becoming turfed over?

Jake: beyond the Glenan burn, Jake nestles under a hazel well away from most human visitors.

 

 

3D Scan VR Showcase:

 

 

3d scan of Frank embedded in a webpage:

Knotty, Weathered Post

 Fencepost of the Week #244