Invaders near Cowbridge

Image: © Mick Lobb Taken: 20 Apr 2009

In what might be considered an idyllic landscape rapidly growing invaders of the hedgerows have sprung into life. I believe this to be Himalayan Balsam (Impatiens glandulifera), an introduced horticultural specimen, related to the Busy Lizzie, that came to Britain in 1839 and has since escaped to become a major nuisance in the wild. It is the tallest annual in the UK growing up to 3 metres tall in a season before dying back in autumn. An attractive plant with a distinctive purple pink flower that belies its destructive nature. Its flower has led to its slang name of 'Policeman's Helmet'- not that I have seen any poicemen wearing pink helmets as yet! Each plant can produce up to 800 seeds and these are explosively released when their pods are mature. The 'explosion' can project the seeds up to 7 metres from the parent plant. This highly effective dispersal method enables the plant to rapidly colonise the damp and riparian habitats that it usually favours. The seeds may be further spread by water, explaining its favoured environment, and can remain viable for 2 years

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