"There is no excellent beauty that hath not some strangeness in the proportion" Francis Bacon 1561-1626

Tuesday, 4 November 2008

Leaf of the Day: The Curious Gold Bearing Horsetail

I love this plant and it has to be another for my imaginary garden, to be planted alongside the cycads in the prehistoric border. I know many dislike it intensely and find it almost impossible to eradicate but we should look in wonder, if only just before applying the weedkiller, at this amazing survivor from prehistory.
The curious horsetail family, the Equisetums developed during the Devonian Period 408-362 million years ago, are related to ferns and no visualisation of a prehistoric landscape would be complete without this strange plant which then would be growing to a magnificent 20 metres.


Image from Universe Review here

Those that survived the extensive late Devonian extinction, joined with the evolving tree ferns, hardy mosses , and the now extinct cordaits to form the first subtropical forests. These plants loaded themselves with carbon extracted from the atmosphere and as they died were gradually pressed into the ground and fossilized as coal and oil. During the Carboniferous Period living and rotting vegetation provided food for insects, spiders, crustaceans, and many other invertebrates, the illustration above also shows a giant dragonfly with 28 inches wingspan. I swear I have seen some almost as big around the lake here.


A horsetail fossil perfectly preserved for more than 300 million years,from the National Geographic website here

The name Equisetum is from the Latin equus meaning, horse and seta meaning "bristle" as the branched form somewhat resemble a horse's tail.They have long, creeping, underground rhizomes which produce aerial stems at close intervals and form thick clumps. The stems are hollow ridged and segmented and you can pull each segment away. The leaves are the tiny fringes at each intersection which are fused into a sheath, the number of leaves equalling the number of stem ridges.
Another name for this plant is the "scouring rush" because these rough and very tough stems are coated with abrasive silica crystals and were used as an effective sandpaper and for cleaning pots and pans. So I can now make pan scrubs to use with my soapberry liquid!



Their design is beautiful, simple and elegant, their reproductive cycle may be beautiful and elegant but simple it is not. It involves spores and cones and words like antheridia, archegonia and prothallium which I have yet to fully understand!..I do vaguely remember it from school biology but need to do some more homework and will do a follow up post . I think diagrams may be needed.

I took this photograph last week at Leu with the sun illuminating the slightly translucent hollow tubes. The contrast of the dark brown and green at the intersections is so attractive.



There are quite a few claims for its health benefits, one talks about it being beneficial for osteoporosis, due to the silica in the stems. Sometimes these cures seem like wishful thinking and sound too much like the frighteningly misguided "Doctrine of Signatures" to me. I wrote before here, about this theory which proposes that a plant's attributes or appearance, in this case the strong rigid stems, indicates it medicinal use.
But it is also sited as being a useful styptic. Culpepper in 1653 found it "very powerful to stop bleeding either outward or inward" and it was applied as a poultice to battle wounds. Young shoots and stem pulp are apparently edible and taste something like asparagus but I don't think it is something I will be trying. Ironically Equisetum is poisonous to horses.
A most interesting fact is that horsetail has the enviable ability to accumulate gold in its cells but it takes at least a ton of fresh horsetails to yield 4 ounces of gold.
And lastly, should you think the nice stiff stems might make good whistles go ahead and try, superstition says you will be whistling up a few snakes as well.

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Horsetail.


2 comments:

Cindy said...

This reminds me of bamboo and orchids all at once. I like your thought of having a prehistoric border and think that would be most interesting. If one stops to think about it for a moment, plants really can have a deep, long history to them.

sharp green pencil said...

Cindy I went to Kew gardens the last time I was over in the UK and they have prehistoric garden.. (well protected by glass) but I was delighted to see all my favourites there. At Leu they have made a few dino foot prints in the path too which is really fun!