Southern Marsh Orchids

Southern Marsh Orchids

Sunday 29 December 2013

Visitor from Afar?


Taking a walk on Kenfig beach today, ambling along the new strand line being created and moved forward by the incoming tide, I noticed a rough looking medium size seed. On examination, it was obviously dense, hard and covered in uneven wrinkles. It is around 22mm long and 25x30mm wide.

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Side View

As far as identification goes, the prime suspect, at the moment is Juglans nigra (J. neotropica is far less likely), the Black Walnut of Eastern North America, the range of which includes Florida, and large numbers of its seeds to find their way into the gulf of Mexico and the Gulf Stream, then potentially to our shores, via the North Atlantic Drift.
It is also grown as an ornamental tree in larger UK gardens, parks and collections and it is possible that this one originated here, but as Black Walnut seed can remain buoyant in salt water for up to fifteen months and they are known to be carried by the Gulf stream, in large numbers to the beaches of the Eastern seaboard of North America, it is just as possible that this is a true long distance traveller.
As I write this, I can see a Coconut I picked up at Kenfig a few years ago. It bears all the hallmarks of one brought here by the Gulf Stream. It is small, the nut is about the size of a cricket ball and still mainly enclosed in its coir husk, which is covered in tiny holes, made by insect larvae burrowing through it. The nut itself has the chalky tube of a Serpulid worm, proving it had been at sea for some time.

4 comments:

  1. Interesting find. I guess the size of the nut suggests non-UK origin - do they ever get that large here? The tree in my local park in Llandaff North only ever produces small nuts (even in hot summers like 2013).

    George

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  2. I don't really know. I remember opening a couple of fallen husks ifound in Westonbirt arboretum and those nuts, although about the same length as this one, were only around a third of the width.

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  3. I find things like this fascinating, it makes you wonder where they have come from and what journey they have been on to get here. Is there any possibility the seed is still viable? I too was out on the beach on the 29th, but at Aberthaw rather than Kenfig. No exotic seeds for me unfortunately but I was slightly depressed by the volume of plastic junk washed up on the beach, some of which appeared to be brands of packaging quite likely to have come from America (or off a boat I suppose). I also picked up a spider from amongst the seaweed and woody debris piled up on the strandline. That seemed an odd habitat for a spider, and I've not been able to id it so I have sent it away for a second opinion. If it turns out to be something interesting it may feature on here in a week or two!

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  4. That spider sounds interesting. I look forward to hearing more about it. Lots of plastic at Kenfig too, most of it unidentifiable, along with the usual unsavoury evidence of overloaded sewer systems. One thing I've noticed a lot in previous visits to Kenfig, but not this time was the presence of plastic moulding pellets, often known as knurdles. These are presumably washed down storm drains in the yards of plastic moulding firms during heavy rain and make their way to the coast in their thousands or tens of thousands. Unless you look closely, you wouldn't be aware of their presence.
    There is an excellent publication by the BSBI called 'Sea Beans and Nickar Nuts', which goes into some detail about 'drift seeds', as they tend to be called and refers to germination of seeds, based on experiments undertaken by variuos people. Most experimentation has probably taken place in America where drift seeds are more common, but of course the seeds washed up there haven't been afloat on the sea as long as the ones you find washed up here. That aside, I suppose the main factors involved in the successful germination of drift seed, apart from cultural conditions, would be the degre of resistance to salt water the seed coat has and the length of time the seed is viable for. Some seed though possessed of a suitably salt water resistant coat might not remain viable long enough to survive the journey.

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