Sunday 17 December 2017

NWNU Mosses and Lichens Walk from Penyghent Gill to Slit Cave and Snorkel Cave

11 November 2017: The North West Naturalists Union Lower Plants group organises a trip once a month. Occasionally they get across into Yorkshire.  In fact this trip is conveniently in the catchment of the River Wharfe so that it can form part of Gordon Haycock's survey of the Mosses of Wharfedale.
Studying mosses as we leave the cars 
at Pen-y-ghent Gill near Giants Grave.

On the way we search for Zygodon gracilis  It does look like other Zygodons but is a bit bigger.
As we study mosses in a wet flush, a fleet of four  four-wheel drives go past.

A lichen on limestone

Cladonia pyxidata on acid rock in wall

Look how there are more lichens on the tops of the wall. The stones here are mostly sandstone from the Yoredale series, with occasional limestone stones included. See the sheepfold lower down. We will later have lunch on the green grass in the shelter of the wall near the sheep fold.

Splendid fossil in the wall - Colonial fossils

More fossils
Here is some Hypogymnia on sandstone
Physcia dubia
See how the mosses are growing below the post.  
This repeated itself all the way along the wall, 
over and over again.

I know! It is because birds perch on the posts 
and add extra nutrients

Indeed look what is growing on the post - The filamentous alga Klebsormidium crenulatum! It is growing on the SE side - but also on the "underside" of the sloping post, where more water and nutrients may drain to.

And on the top wall stone - evidence of birds themselves

With a piece of Xanthoria parietina (orange lichen)

We descended past Slit Cave - Those slippery wooden slats on the stream bed at the left of the picture cover..  a hole.

I find this strange fungus - Cordyceps - growing out af an insect it has parasitized

Her is bird's-eye Primrose - on 11 11 2017 -November!!

And we continue down, down down the side gill

Another lichen

And another on the first tree we have come across, at the bottom of the gill - Hypogymnia physodes.

We meet the Penyghent Gill Stream at the bottom and then have a long vigorous 3km walk back along the side of the gill whilst daylight lasted. I slither to a horizontal position in the mud at one point objecting violently..( but it does mean that I later give my jacket a long needed wash) We return to the cars as night falls.  Thank you  Gordon for organising the event and thank you to the others - Mike, Sam and Clare for coming.  

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