Wednesday 9 September 2009

Harebells, re-visited


Although I have waxed on about harebells before, I need little excuse to do so again. Walking one of the footpaths that cross Bamburgh golf course the other day I came across a small patch with pure white flowers in the rank rough between the fertilised fairways.

So, (he says, looking in the general direction of Greenfingers....), is this unusual? Is it a variation in the wild harebell or might these be a different species or variety given that this is a heavily managed golf course?

6 comments:

  1. I found some amongst the more ususal blue north of the Snook too in July so I dont think it has much to do with golf course management.

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  2. I recollect seeing some white ones along the coastal path between Craster and Cullernose Point. There seems to be some variation in the intensity of colour on harebell flowers but I think pure white ones are likely to be mutants, with a defect in the biochemical pathway that produces the blue pigment in the flowers. I wonder if it makes them more of less attractive to pollinating insects? Harebells can self-pollinate if they're not visited by pollinators (see http://cabinetofcuriosities-greenfingers.blogspot.com/search/label/Campanula%20rotundifolia) and if they did self pollinate the white flower colour would probably breed true in the offspring, maintaining some white plants in the population once the initial mutation had arisen.

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  3. Thanks Phil. This patch was all white and there were no blue ones even in the vicinity so does that mean that they must have self pollinated then? (My genetics is a bit rusty and basic but am I right in thinking that self-pollination means they are all clones?)

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  4. Hi Nyctalus, it suggests that the white flower characteristic is a homozygous recessive mutation which would breed true (i.e produce all white offspring) if it self-pollinated. They wouldn't be clones because the white-flowered parent would most likely be heterozygous of other gene loci, so offspring would be variable for those characters....

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  5. Could it be that they are infected with some virus or fungus? Often you see patches in fields of creeping thistle that are white-flowered instead of the usual mauve colour. This, I've been told, is some sort of infection in the soil. I'm sure you don't need an excuse to go back up to Bamburgh, so I suggest that you collect some seed and try growing them to see if they come true or if they're white on flowering.

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  6. Hi CC. Another interesting angle that I haven't heard of before. As it happens I may well get the chance to collect some seeds so may take up our idea.
    A

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