Wednesday, April 21, 2010

300 Million year-old Survivors

These are the fertile shoots of great horsetail Equisetum telmateia, photographed along the Long Walk at Howick on the Northumberland coast last weekend. Each one of those small polygon-shaped objects in the cone-shaped head releases hundreds of spores. You can see some micrographs of spores from a similar field horsetail here. Horsetails are the last living descendants of a group of plants that flourished back in the steamy Carboniferous swamps, 300 million years ago, when the coal measures were laid down. Carboniferous horsetails, classified in the genus Calamites, were essential similar to their living descendants but much larger, some reaching 10 metres in height. As soon as the fertile shoots of great horsetail have shed their spores they wither away, but by then the green vegetative shoots of this year's plants will have begun to elongate and will eventually form dense one metre-tall thickets of stems - minute compared with their extinct ancestors, but still impressive.

9 comments:

  1. Your blog is exciting and very informative. A pleasure to see and read about this botanical curiosities. Greetings from Luzia.

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  2. Phil thanks once again. You are tending to overload what few cells I have left. Keep it up, I enjoy life much more the more I know. How tall are these shoots? My eyes are at about six feet so don't want to tread on one. Will see if there is parking round Howick and have a look for myself.

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  3. Fascinating. I always learn so much when I visit here. A great shot too.

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  4. I've always admired the horsetail because of its history. I like to let some flourish in the garden as a link to a time millions of years ago. It would be amazing to see 10 metre tall horstails but those must have been scary times!

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  5. Thanks for your kind comments Luzia

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  6. Overlaoding people with info is a bit of an occupational hazard when you're in the education trade, Adrian. The shoots are about a foot tall - field horsetail is about half that size.

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  7. Thanks Keith... weird plants, aren't hey..?

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  8. Hi Lesley, this one would probably be OK as a garden plant but the field horsetail is a weed that you just can't get rid of (it's in my garden) ... it has deep underground rhizomes, which some people call 'the devil's guts'!

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  9. You know Phil, I'm getting muxed ip again! I was thinking of Marestail which looks different altogether. I don't think I have enough working brain cells to cope with the overload that Adrian mentioned. :O) And remember my mix up with the garden centre names? Well, on our way to Chester-le-Street last weekend, we saw that Foxwood Garden Centre has now become Chesters Grove!

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