Saturday 14 March 2015

coastal tufa liverworts

A few more trips on the Glamorgan Coast over the last few weeks. Highlights include accidentally finding the most easterly record of the Maidenhair Fern Adiantum capillus-veneris associated with Pellia endiviifolia and Eucladium verticallatum on a small patch of tufa in a small crevasse in Penarth cliff (most easterly record) and only confirmed record in the ST17 square (ST1865769887). It was also at this location that gravity supplied me with a nice block of tufa, which I duly sliced in half – noting it was entirely formed from numerous layers of Pellia…I wonder how long this takes to form and could it be geochemically dated ?

Pellia endiviifolia forming its own lump of tufa 
Thus far the majority of the coastal tufa cliff face liverworts appear to be Pellia sp however Julian Woodman (NRW) took me to see the elusive Southbya tophacea at the Aberthaw-Fontygary cliff section. It took a bit of squinting but once located we could just about get close enough to it for a look with our faces pressed up against the dripping rock face.  It occurred over a 10-20 m section, not continuously but in small patches, the cliff face protected by scrub and other plants, providing shade and protection from sea spray and winds. In places it looked like it was being ‘overcome’ by other more vigorous mosses but that may just be my novice eye.
Julian Woodman up close and personal with Southbya and a lot of Maidenhair Fern
blink and you'll miss it:  Southbya tophacea in amongst bases of the Maidenhair Fern - perhaps it will be associated with the fern elsewhere across the coast??
After a spot of lunch in the Fox and Hounds we popped over to Southerndown to the Cwm Mawr stream (SS8936572263), that’s the one that forms the waterfall that cascades onto the beach below. The stream section up on the cliff is quite spectacular tufa forming stream jam packed with mosses and liverworts in amongst a thick matt of yellow iris over a 100m or so stretch.


Cwm Mawr (SS 89365 72263) view to east - at least 100m of tufa forming stream packed with goodies in between yellow iris matt. Worth a visit Barry ?
The most common liverwort at Cwm Mawr was a thallose liverwort with thallus >1cm, lacking obvious midrib (to me anyhow),  gammae in obvious receptacles, upper surface of thallus covered in air pores in the centre of polygonal markings,  the capsules are distinctive ‘mushroom shape’ and I cant seem to find this in ‘the book’ or get close using the key. Can anyone help ? Im guessing its a common species.
Cwm Mawr SS 89365 72263 tufa forming stream above the cliff. I'm stuck on the ID for this thallose liverwort can anyone help, its distinctive 'mushroom' shaped capsule should be a give away ?

7 comments:

  1. Excellent stuff Gareth. The liverwort is Conocephalum conicum - if you have a sample then have a sniff, it should be very strongly scented. I've not seen it fruiting.

    I've seen tufa above the beach towards the southern end of Dunraven Bay - not sure if you've looked at that bit? Barry and I have (independently) recorded Eucladium there.

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  2. cheers George, yes I did have a sniff and it does have a scent, there was loads of it along the Nant y Cwm Mawr. I didnt get down on the beach section at Dunraven this time but will do soon. Off to scout some Maidenhair fern tomorrow just in case Southbya is living at its feet just like at Aberthaw.

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  3. Gareth, I wonder if your reference to 'gemmae in obvious receptacles' means that you also saw Lunularia cruciata? may be worth you checking? I'm glad Julian has shown you the Southbya (I think the Fox & Hounds is where we had lunch when he showed me too!), so at least now you know what you're looking for. Well done with the Eucladium btw, these coastal enclaves are great to stumble upon.

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  4. Oops yes I missed the bit about gemmae in the text, thanks for pointing that out Barry.

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  5. Hi Barry, ah yes the gammae were in obvious receptacles but they were cup shape rather than crescent and the polygonal shapes around the pores were very distinctive.....Ill get a camera adapter for the microscope soon so I can record what I see. Fox and Hounds was great, could have stayed in there all day !

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  6. Sounds more like Marchantia, but a pic would be invaluable

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  7. Hi Barry - the picture at the base of the blog is of said liverwort. Have high powered microscope on way so should help the finer parts of ID !

    Cheers
    gf

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