Thursday, 22 May 2014

Foxglove (Digitalis purpurea)

Any Fairies Around?
Foxglove and Sedum
      Foxgloves are normally a biennial plant, meaning that they produce a rosette of leaves in the first year, flower in the second, then snuff it. However, they've not all read the books, so you inevitably get some which decide to go on flowering over the next few years. Perhaps that's just a stage in their evolution or maybe they've always varied like that. Anyway, the point is, that I've usually seen them as a nuisance and a weed when they pop up where I don't want them and this year I gave them a bit more thought: they're an attractive flower and when one appeared growing adjacent a Sedum spectabile I decided to leave it because it flowers early and can be removed when they finish, leaving the Sedum to present its display unimpeded later in the summer. This should be a major rule in gardening: maximise the use of the space you have, so that there is always something of interest.

      The flowers on foxglove (Digitalis purpurea) open first at the bottom and work their way up over a period of weeks. The reasons given for this are twofold. Firstly, it gives security against bad weather which will keep bees, their main pollinators, in bed until it cheers up and secondly, its normal habitat is in areas where tall grasses and other plant are liable to grow up around it and hide the flowers from bees, so later flowering to the tip of its spire ensures they will still be seen. Nectar is secreted at the base of the flower, attracting bees which follow the 'runway' marked out with spots. They have to force their way down the flower to the nectar and, in so doing, rub past the anthers, picking up pollen which gets transferred to the next plant they visit.
Getting Pollinated
      Reasons for the name foxglove remain debatable. One which I may have mentioned before is the closeness to 'folk's gliew', the 'folks' referring to the little folks or fairies and 'gliew' to a Saxon musical instrument made of small bells - fairy bells. I like this explanation but it is poo- poo'd by the experts who maintain that, in Old English, it was called foxes glofa. This may well be, but the fact that it has a number of names, including fairy's thimbles, dead men's thimbles, tod-tails, floppy dock, fairy gloves and fairy bells, suggests to me that it seems reasonable to assume that it was always called a few things. Therefore the choice of foxes glofa proves nothing except that no one really knows the truth of the matter.
Yellow foxglove (Digitalis grandiflora) which arrived uninvited
      The history of medicinal use of the foxglove is quite interesting: a bloke called William Withering, a physician in the mid eighteenth century, came across a remedy for dropsy which contained foxglove. Knowing that heart failure often caused dropsy, he did careful analysis and came up with digoxin, which is still widely used for heart treatment. This finding is recognised as the tipping point from folk medicine into scientifically based modern treatments. I'm always interested in the derivation of names and like to think that Bill Withering's came from a facility to belittle someone with a look rather than a propensity to kill plants.

      As it is throughout life, you can have too much of a good thing and poisonous foxglove is a case in point: the right amount can save your life, whereas a bit too much can lead to the funeral insurance being cashed in.

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