Wednesday, 29 October 2014

Jubula hutchinsiae in Glamorgan

Between Glyn Neath and Pont Walby, at the head of the Neath Valley, there is a fabulous trackway which was the course of an old railway line. It is has huge vertical embankments plastered in bryophytes and is dissected by little valleys with Tilia cordata and (native) Acer campestre (both rare in NPT). At SN8865/0630 there is a waterfall which has quite a bit of Jubula hutchinsiae on its rock face.
Jubula hutchinsiae, Glyn Neath (28/10/14)

 This beautiful, grey-green liverwort is unmistakable with its spiny leaves and distinctive underside.

Underside of Jubula hutchinsiae showing helmet-shaped ventral lobes

The small, helmet-shaped ventral lobes are reminiscent of Frullania, but the spiny, holly-like leaves are characteristic and give it its common name, Hutchins' Hollywort.
I have never seen this species in Glamorgan before. However, there is a vague record in the Mapmate database which refers to a record from the Blaen Nedd and Mellte SSSI (SN8908), which originated from a CCW database (1975-1996). The same database entry holds records of Jamesoniella autumnalis and Fissidens rivularis. The grid reference suggests a monad in Glamorgan but I think the actual site for these record is Nant-y-celin (near Craig y Dinas) where J. hutchinsiae has been known since the 1970s and which is in Brecs.
Jubula hutchinsiae is a Southern Atlantic species with a very western distribution in Britain. It is rather scarce in South Wales. 

3 comments:

  1. PS: Other species in vicinity include Dicranum fuscescens, Saccogyna viticulosa, Hyocomium armoricum, Riccardia mutifida, Preissia quadrata, Gymnostomum aeruginosum, Amphidium mougeotii, Hookeria lucens. I'll post some photos of the site later.

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  2. Sounds wonderful. Quite a few species on that list which I've never seen (including Jubula!).

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  3. Sounds worth a visit some time when I'm in the area. There's a chance the monad record could result from confusion during LRC data entry: I am sorry to say that BIS input all species mentioned in SSSI citations as though they were records made in the year of notification from the SSSI centroid. Other problems were widespread but not so obvious :-( I have found SEWBReC bryo data to be much more accurate, but the LRCs pool their data.

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