Cwm Idwal, Snowdonia

[Tristan_He]

Tim Ingram's post mentioning the Snowdon Lily on another thread reminded me of Cwm Idwal, one of the best Arctic-alpine locations in Snowdonia. There is a nice litte video here:


Also if you want to see what I get up to when I'm not posting on this forum, here is another little video about some really fabulous lakes:
https://www.youtube.com/watch?v=YSIsGYOKqdM&feature=youtu.be&a=

[Tim Ingram]

Thank you for showing those Tristan. They are so well presented and clear and it makes me wish we didn't live so far away from such wonderful and interesting landscapes. I think also its a great example of the value of this Forum and the Scottish Rock Garden Club and looking at landscapes in true detail. I learned a lot from watching them.

[Matt T]

That brings back memories! I did some field work at Cwm Idwal (and many other sites through Snowdonia) during my undergraduate study. I've not been back since, and how it's changed! A joy to see these videos, thank you. I must visit again.

[ian mcdonald]

Good countryside. A bit flat here apart from the pit tips. Perhaps in a thousand years they might improve?

[Tristan_He]

Yesterday we finally got around to doing something I have never quite managed to do in more than 15 years living in Wales... go out to look for purple saxifrage (Saxifraga oppositifolia) in flower. You know how it is when something is nearby, it can always be done another time and so never quite gets done at all.

Globally this is a common plant as alpines go but here in Wales it is quite scarce, being found only on a few of our less acid mountain-tops as an Arctic-alpine relict species. It's one of my favourite garden plants. The Cwm Idwal population is quite accessible but is still a little climb up from Llyn Idwal, the lake.


At least two other saxifrages grow here as well. I think this is Saxifraga stellaris.


View down to Llyn Idwal, a shallow nutrient-poor lake with clear water and a nice plant community.


The purple saxifrage grows in a field of massive limestone blocks just below the crack in the cliff known as the Devils Kitchen.


My first sighting of purple saxifrage in the wild.


...and now in flower!

[Tristan_He]

Some more photos of flowering purple saxifrage. Although this is quite a small and isolated population, I was quite surprised by the amount of variation.

[Matt T]

Great photos, Tristan! They remind me to try to find a free day (haha!) to get out on our own local mountains before too long.

[Tristan_He]

We also saw some other interesting things. Another familiar friend, Saxifraga hypnoides, not in flower yet of course.




Cwm Idwal is one of the wettest places in the UK with 4000mm of rain typical, so some nice bryophytes and ferns. I rather liked this natural moss garden on a boulder - anyone know their bryophytes? The fern is Asplenium trichomanes.


Something I hadn't seen before - though it is reasonably frequent in Snowdonia - is filmy fern. These plants need constant high humidity. I think this is Wilson's filmy fern, Hymenophyllum wilsonii.


Looking up the boulder field to the Devil's Kitchen (in Welsh Twll Du which means black hole). This narrow cleft in the cliff emits steam sometimes apparently (presumably high humidity on a warm day) and it is said the Devil is then cooking in his 'kitchen'.


Another spleenwort, this time green spleenwort Asplenium viride - new to me.


We plan to make another trip later in the year to try to spot some of the other species that grow here, such as moss campion and perhaps even Snowdon lily (though I understand this is quite inaccessible).

[Tristan_He]

Great photos, Tristan! They remind me to try to find a free day (haha!) to get out on our own local mountains before too long.

Thanks Matt. I dare say there is a good deal more to see in Scotland too, Wales is a real outpost for alpines, sadly. I also wonder how much of an effect acidification had on our upland plants.

[Dave M]

Excellent photos Tristan. I love Cwm Idwal. I'm shortly taking a group of NGO and statutory land managers and conservationists from the Lake District to inspire them about this site and showing that doing the right thing (getting heavy sheep grazing off) can have some huge benefits for our native upland alpine flora. I'm hoping we can roll out this approach on a few key sites in the Lakes over the next couple of years.

I know what you mean about getting out on local sites. I live close to Ingleborough but spectacularly fail most years of late to get up looking for Sax oppositifolia at flowering time, despite having it in full bloom now on the scree bed outside the front door hinting at me!

[Tristan_He]

What a good idea Dave and best of luck. I presume you are already in touch with Hywel Roberts?

[Gabriela]

Tristan - Cwm Idwal rocks! Beautiful landscapes, and so nice to see S. oppositifolia in flower. I never get to catch it in flower in the Carpathians and here grows too far up north. Also a very nice collection of ferns - the filmy fern is completely new for me, have to google about it.
No monsters in those pretty lakes you study?  

[Tim Ingram]

Wonderful pictures Tristan! I wonder how an earth we manage to grow Saxifraga oppositifolia here (admittedly not too well) with only around 600-700mm of rain annually?! Actually Asplenium ceterach and A. trichomanes also grow quite well in the sand bed with some irrigation in the driest periods but I would definitely prefer the landscape to go with them!!

[Hoy]

Most interesting, Tristan! The landscape of Wales is completely unknown to me except from a few pictures.

I hope you find the Snowdon Lily. It is not known from Norway although it should have grown here

[Tristan_He]

Tristan - Cwm Idwal rocks! Beautiful landscapes, and so nice to see S. oppositifolia in flower. I never get to catch it in flower in the Carpathians and here grows too far up north. Also a very nice collection of ferns - the filmy fern is completely new for me, have to google about it.
No monsters in those pretty lakes you study?  

We certainly enjoyed it Gabriela. I've seen the photos of this species from the Arctic Circle though where it looks to be really spectacular.

We have quite a nice range of hyperoceanic bryophytes and ferns here in Wales - basically things that need constantly wet conditions. There is some suggestion that some of them don't disperse much at the moment because the climate is too dry! Sort of 'Atlantis relicts'. Many of the same species also occur in western Scotland.

We have the same number of monsters as in Scotland 

There are one or two myths and legends but none really seems to have caught the imagination. See for example here:
http://www.mysteriousbritain.co.uk/wales/gwynedd/folklore/lake-bala.html and here:
http://cryptozoo-oscity.blogspot.co.uk/2010/06/lake-bala-creature-sightings.html
and here: https://en.wikipedia.org/wiki/Afanc