The Cardiganshire Laburnum
Mystery.....
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Why is such a poisonous plant used in
hedges?
In Ceredigion, as well as Carmarthenshire,
many field hedges are planted with the Laburnum tree (Laburnum
anagyroides). In May and June, its long bunches of
pea-like yellow flowers provide an unlikely splash of colour
with its showy flowers giving this tree the alternative
names of 'Golden Chain Tree' and 'Golden Rain Tree'.
Some of the best displays of Laburnum can be
seen bordering old fields beside the coastal A487 between
Llanarth and Cardigan. Laburnum is also
used as a hedging
plant in Carmarthenshire and other parts of South Wales as well as
in parts of Shropshire.
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The Laburnum is indigenous to the mountains of
Central and Southern Europe, but is now widely cultivated
across Europe and Britain. The tree was first introduced to
Britain in 1597 at which time the famous medieval herbalist Gerard
appears to have grown it in his garden under the names of Anagyris, Laburnum, and Bean Trefoil.
The mystery of Laburnum is that it was so widely planted as a
hedging plant about 150 years ago in West Wales when all the parts
of the plant are highly poisonous to both farm animals and
Mankind. Indeed , there are many references to the fact that
Laburnum should never be planted where farm animals can reach
them!
The poisonous alkaloid Cytisine was first discovered in 1863 by as one of
several poisonous alkaloids present in the seeds of the Laburnum. Cytisine
is a white, crystalline solid, with a bitter, caustic taste, and a very poisonous action. It has in the past been recommended
as a cure for whooping cough and asthma. Symptoms of poisoning by Laburnum root or seeds are intense sleepiness, vomiting, convulsive movements, coma, slight frothing
at the mouth and unequally dilated pupils. In some cases, diarrhoea is very severe.
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Laburnum hedges have
been coppiced and have a characteristic shape. This hedge is
near Brynhoffnant on the A487. The photo was taken in the
spring just as the leaves were starting to open.
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Despite its poisonous nature, Laburnum does have some use. The heart-wood of the Laburnum was often used as an Ebony substitute
as it is very hard and coloured a dark chocolate brown. The sapwood
surrounding the heart-wood is in contrast a bright yellow. The
wood has been used for making the handles of tools and for use in
various crafts.
Certainly the Laburnum has been planted for its decorative
value. There is a specimen tree planted in the lawns below Glanmor
Terrace in New Quay, and many were planted in parks and gardens in
the 1940's and 1950's. Maybe, farmers in Ceredigion also planted
them as hedges for their colour. Whatever the reason, there
remains little recorded evidence other than the trees themselves.
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