Monday 5 December 2011

Then and Now: Invasion By a Foreigner and Near Native Extinction.

Thomas Cockerline (9.6.1891 - 8.2.1979), was an only child who at an early age developed an interest in botany and started his own extensive herbarium collection, left to Leeds Museum when he died. He was a long standing member of the Leeds Naturalists' Club and during the late 1960s/early 1970s he was elected President of the Leeds Naturalists' Club, and held the position of Hon. Council Member until his death.

During my internship here at Leeds Museum Discovery Centre I have been helping to complete a photographic record of Thomas Cockerline’s herbarium collection. Throughout this I came across two specimens that particularly interested me, a Vicia bithynica specimen and an Epilobium pedunculare specimen.
Vicia bithynica (Bithynian Vetch) is and has been for some time a rare and declining species of legume. It is a scrambling annual found in rough grassland on coastal under-cliffs and inland in open hedges, scrubby grassland and on railway banks. The flowers are a beautiful purple with white wings and keel and this plant has distinctive toothed stipules (leaf-like structures at the bottom of the leaf stalk or petiole).

This particular specimen interested me because of the photograph and newspaper cutting attached. The photo of the footbridge, at Upgang Ravine near Whitby, is mentioned in the newspaper clipping, which states concern from local botanists about the development of a new footpath to the bridge that will destroy the habitat of this rare species, found in only a few places in the north of Britain.

Being a plant enthusiast I found this intriguing, particularly because this species is rare. After some further research I found that Vetch species have some very useful attributes, being excellent nutrient managers of the soil, which can benefit the growth of crops grown collectively. This is because they are legumes and can fix nitrogen, producing enough to support almost all of the needs of the subsequent crop, as well as making potassium more available.


I did find some excellent news online from the UK wild Flowers website, where someone has recorded (2005) a relatively large population of Vicia bithynica on a hillside by the sea at Upgang Ravine.

The other herbarium specimen that interested me was of the species Epilobium pedunculare, native to New Zealand but thriving in the British Isles, to the extent it is often referred to as a ‘garden thug’. This ‘little foreigner’ is considered a weed, but we have only ourselves to blame for its invasion into our countryside via dispersal of seeds from our gardens.

This species is excellently adapted to the British climate and as stated in the issue ‘The Naturalist’ from Oct-Dec 1947, it has a preference for wilder places amongst the hills and moor-lands and is also commonly found growing amongst Sedges.

Posted by Clare but researched and written by Hannah Yeadon who worked diligently on the wonderful plant collections at Leeds Museum Discovery Centre in 2011.


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