SD86 - 17 - SD8167- Lecanora rupicola - Stainforth NW - Big white lichen - on exposed faces on ACID ROCK

 

Craven is blessed with many rock types. Hence - many different lichens.

The cat on the right is admiring the Lecanora rupicola on a slate gravestone at Horton in Ribblesdale.

This post deals with a walk near Stainforth to look at Lecanora rupicola - with digressions to Horton in Ribblesdale and the Coast of Anglesey

Landmark lichen 1 - was Aspicilia calcarea forming big white patches on limestone wall tops.

Today we are going to look at another big white lichen - this time on vertical faces on ACID ROCK - e.g above Stainforth 

( It also occurs at local beauty spots I have visited outside out side our hectad - e.g. Horton in Ribblesdale Churchyard, Low Bentham Churchyard, and especially on some Scottish  and Welsh Coastal sites where it is a dominant lichen).

Acid rocks can have OTHER BIG WHITE LICHENS as I mention at the end of the post.  But let's do Lecanora rupicola first

Landmark Lichen 4: Lecanora rupicola

This striking big white lichen grows on acid rocks:, especially vertical acid rocks.. but not just any acid rock. It seems to do well on selected slates and greywackes on the very old rocks that appear at the surface of our world  above Stainforth and Horton in Ribblesdale (Ordovician and Silurian).

Wall just north of Stainforth -See Stainforth church to the right

I went back on a sunnier day on 1 April to try and get a brighter picture

The lambs in the field were enjoying the warm afternoon

Some of the most striking patches are at Horton in Ribblesdale churchyard, three miles to the north

Horton in Ribblesdale Churchyard

The map shows it  grows especially well beside the coast.

I have also seen it on rocks on walls on romantic western coast headlands in Scotland where there is much more of this ancient rock'

Features:-

1. Forms big white patches
   
   
2. The thallus is thick
   
   
3. When thalli grow next to each other there is a noticeable line where they meet (giving a map effect a bit like Rhizocarpon geographicum.)
   
   
4. The thallus can be divided into areoles with wiggly edges. But sometimes areoles don't form.
   
   
5. The thallus stains yellow with KOH
   
   
6. If it has apothecia. They can be big (1-2mm) with a cream-pinkish disk and a white border. 
   
   
7. The disks can also be dark and have a crinkly border
   
   
8. They can also be immersed.
   
   Confusing?
   
   
9. The apothecia can often be infected with a parasitic lichen called Arthonia radians. This is dark grey/black and can make the whole apothecia look black.
   
   
10. If infected the apothecia can be sunken and several per areole - and then it looks like Aspicilia calcarea - But you would rarely mix them up because they grow on different rock types.

Lecanora rupicola at Horton Churchyard

Lecanora rupicola stains yellow with KOH

Here the discs are pink

Two thalli meet.
Here some discs are pink and some are black. the black ones may be infected. Well even some of the pink ones look a bit infected.

Some pictures from the coast of Wales:-

Lecanora rupicola on ancient acid rock on
Holy Island, Anglesey. on a BLS field trip


Below: more rocks by the coast on another day of the trip

Back to Stainforth.

I carried on north to the next field, to the field north of Rains Barn

where there is a stream running down the hillside (when it is wet) and cutting through these ancient acid rocks.

Here I  found some other lichens: 

Such as a favourite of mine Xanthoparmelia conspersa

with the view looking back to Stainforth

A little higher was this rock with the same view looking back to Stainforth Church. Close examination of the "Big White Patches" revealed that some were not so white.

In fact the patches were yellowish - a good candidate for Lecanora sulphurea 

Higher up I found some more white patches. A completely different species. But I'll describe it in another post.

Just note the zoned effect at the margin (like an oyster..) above  
and a close up below show lumps which turn into white soralia,
and the reaction with K (at abut 11pm) was negative and the reaction with C (centre and 6pm) was shocking pink.  - Or if you can guess put your suggestion in the comments.

Some "Daddy " sheep came to see what I was doing.  

(Tups- "Leicesters of some sort?")

 Time to return home.