Thursday 31 January 2019

Lichens at Painshill Park Surrey with BLS

The British Lichen Society Day Field Trip on 27 January 2019, followed the AGM at Kew, and was  held at Painshill Park, Cobham, Surrey. 

Six of us piled into a taxi - row of three facing row of three - good for talking -  and were driven to the park where we met the other four lichenologists.
Lichenologists returning on the far left
Painshill is a beautiful award winning 18th century landscape garden which was created between 1738 and 1733 by the Hon Charles Hamilton.

THIS Account IS CURRENTLY A DRAFT ACCOUNT, and only half written, - whilst I await comments on identification of one or two species by more experienced participants, and find time to write up the second half..


I recorded 47 species - 14 of which were new for me.


  • This is mostly because I come from the north of England so was pleased to see species that are more common in the south..
     
  • and also because I now have the Seventh edition of Frank Dobson's book, (2018) rather than just the Fifth (2005) . (In the 2005 edition, He says he covers nearly 850 species out of the 1800 species so far recognised in Britain. In 2018 he says he covers more than 1000 species of the 2000 species so far recongnised in Britain.) !!!
  • but mostly because there were experts who could tell me what the species are.
I suspect the group total list will eventually come to nearer 80 or even maybe 100.. We'll see..

(Ah!  110 reported by Friday 1 Feb  !!)


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The Day


Paul Cannon tells us that only one lichen record had been sent in from the Park. There is lots of scope for new records! There is a possibility that a A3 road widening scheme will affect the far end of the park so he is keen that we should visit that part too in our walk.

We don't get far. The very first tree in the car park has good specimens of Punctelia subrudecta and Punctelia borreri. Borreri has whiter edges to the thallus (and is black on the undersurface of the thallus
 at the centre , and is much more abundant in the south of England).
These pictures are not always brilliant - and are presented in some cases just as evidence that I saw them.  However for both species you can see the white lumps on the thallus (pseudocyphellae) which burst open to form soralia, and the farinose soredia come out.


Punctelia subrudecta (common all over England): Darker Grey.
  


Punctelia borreri  (found mostly in the south of UK)



We cross a bridge onto an island 




On the soil near the shore is a Micaria. Any ideas which?

 On top of the island (and leading to the Grotto) are limestone arches. The rocks are oolitic limestone I was told and have been brought from Gloucestershire or Bath.





We find species that I would expect on limestone such as  some of the species that dissolve holes (like verrucas) for their reproductive bodies:- 
e.g. Verrucaria baldensis except that it is not called Verrucaria any more, it is called Bagliettoa baldensis. 

Then I was shown a new one for me: Bagliettoa calceseda - It has a thicker lime impregnated thallus and the surface is uneven, the perithecia - holes - are bigger and have cracks radiating from the perithecia (occasionally) (and have no involucrellum). (It wasn't in Dobson 2005)

Bagliettoa calceseda 




Lecanora crenulata grows on limestone



Lecanora crenulata grows on limestone. The ascocarp border is crenulate and the surface of the ascocarp is pruinose (whitish)






Caloplaca limonia:  pale creamy yellow thallus: convex areoles covered in granular soriedia
(C. limonea was just included in C citrina agg on Dobson 2005)




The yellow is Caloplaca citrina (agg?)  Not areolate. soredia diffuse.
The green is
  Lecania erysibe - there is a closer version of this below:




Lecania erysibe

Thallus covered with blastidia which resemble minute granules but are formed in short sparsely branched chains forming a lyer typically 2 to 3 deep. and are green in well lit situaltions. Apothecia .3-.4mm diam with brown slightly conves discs and densley blastidiate margins.  A blastidium is a globular propagule, containing mycobiont  and photobiont, always produced by "budding" and frequently formed in series of two or more, with each new blastidium produced from the tip of the previous one. common on calcareous and nutrient enriched substrates in UK and lots in N and S England and in urban situations.


Lepraria vouauxii



Lepraria vouauxii
This is supposed to have a thick puckered edge consisiting of powdery granules up to 0.5mm across, often eroded and showing white medulla. See the tiny snail!
It is frequent in lowland Britain on mortar rocks and ash trees.
It goes orange when bleach is applied.


Lecidella stigmatea -seen closer below



Lecidella stigmatea - zoomed in.
The thallus is areolate or cracked
It is common on calcareous rocks.






Acrodordia salweyi  growing on the limestone. The fruiting bodies are like semicircular domes, (whereas Acrocordia conidea has cone shaped domes, and a pinker thallus)


After this I went down into the Grotto.

There is a brick frames (which you cannot see) covered outside with the limestone and inside with crystals.

It was dark inside, except where daylight was allowed to stream through.  Bu when a photograph is taken the gypsum and other crystals reflect the light.


    
    


There were two guides inside who told us about the history..
I listened awhile. Apparently Charles Hamilton ran out of money for building the grott. It was renovated and rebuilt just a few years ago.

.... Click here to find out about  the afternoon lichen walk later..



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