Saturday, April 25, 2009

Two heads better than one?


Found this twin-headed dandelion with a wide, flat flower stalk yesterday. There are usually four possible causes of this kind of abnormality: (1) A mutant plant – but if it was a genetic mutant all the flower heads would have been like this, not just one. All the other flowers on this plant were normal. (2) A sub-lethal dose of herbicide – but there were no signs of herbicide damage in any of the surrounding vegetation. (3) A soil bacterium called Corynebacterium, which causes the fasciation sometimes seen in twigs of woody plants like Forsythia, where the stem is wide and flat instead of having a circular cross section – a possibility. (4) Damage to the bud during the earliest stages of development, perhaps by an insect – my favourite theory, in this case.

3 comments:

  1. Well, whatever caused it, it certainly makes a stunning picture. Never seen anything like that before.

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  2. I recently saw three dandelion heads on one stalk. It was interesting, still looking for the root of the cause.

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  3. Hi nannabe, I think that sometimes sub-lethal doses of herbicide can cause these developmental abnormalities

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