Today we returned to an old ‘favourite’ – the Merstone Stream
in Blackwater for our first Himalayan Balsam pulling session of the year. We are all delighted to be back to this
perennial task! The HB is not in flower
yet so it is not immediately obvious where it is, but once spotted we found a
considerable amount. The majority of the
HB was found along the steep banks of the stream, so access was difficult. GG-er Graham donned waders and, with support,
worked along the stream. Adjoining
fields along the NE bank of the stream were also cleared.
Himalayan Balsam was introduced to the UK by Victorian plant
hunters and is a very successful plant due mainly to its method of dispersing
its seeds, usually along watercourses. Our
usual description of the seed dispersal is that the seed pods explode, ping, pop
or burst. However, the following link, via GG-er Ken (and his Dad), has a more
scientific explanation:
‘Ballochory is a type of dispersal where the seed is
forcefully ejected by explosive
dehiscence of the fruit. Often the force that generates
the explosion results from turgor pressure within the fruit or due to internal hygroscopic
tensions within the fruit.’
