DANGER
IN THE GARDEN
I chose a career in horticulture as I just loved growing plants and
enjoying the beauty of flowers, and it has only been lately that I
discovered just how many garden plants contain toxins, poisons and
skin irritants. In the early training years it was the Laburnum with
beautiful golden yellow flowers followed on with poisonous seeds.
Laburnum vossii |
Dumb cane |
Similarly the host of plant poisons is seldom a problem as there is
little reason to eat something that would taste horrible. When
looking into garden plants with poisons I was just amazed at the long
list, (the Royal Horticultural Society has a list of over two hundred
plants) and so many are our every day plants grown in gardens and
house plants. Rhododendrons, daffodils, aconites outdoors and indoors
we grow poinsettias at Christmas and forced hyacinths as well as dumb
which if ingested can cause immobility of the
mouth and tongue, difficulty in breathing and asphyxiation.
Aconites have powerful toxin, aconitine, which can kill people
who come into contact with it. All parts of the plant are toxic
but the sap in particular is a skin irritant, causing burning of
the lips and mouth, vomiting, diarrhoea and spasms.
Winter aconites |
Over time plants have developed numerous ways to aid survival from
thorns on stems to poisons in leaves, stems, bark, seeds, flowers and
roots to discourage other animals from eating them.
Arisaema sikokianum |
Outdoor public landscapes contain laurels, rhododendrons, snowberry
and yew trees. Every part of the yew tree is poisonous The stems, leaves and
seeds contain the toxic alkaloid taxine. Monks would use them to mark
and protect the routes of their pilgrimages. They would collect the
yew seeds as a food source and eat the aril, but spit out the seed as
they travelled on their pilgrimages.
except the
fleshy aril around the seed.Brugmansia Angels Trumpets |
Euphorbia griffithii Fireglow has a milky
sap, which is extremely irritating to the skin and eyes.
Deadly nightshade |
English Yew with berries |
Arisaema sikokianum, an
attractive bog plant produces fleshy seed coats contain oxalic acid
in the sap. Opium poppies are
quite commonly found in gardens brought in by birds, but the sap in
the seed head contains opium. Another garden plant used in tubs to
flower in summer is the Angels Trumpets, Datura stramonium. It has
attractive large scented tubular white flowers, but every part of
this plant is toxic. South American native Indians use it as a drug
because of its hypnotic and hallucinogenic affects, but in the wrong
dose it can be fatal. However to keep matter in perspective, very few
folk suffer from plant poisons as we usually only eat those foods
that we know and like, but then you find that some of our everyday
foods contain poisons. Take apples, tomatoes and potatoes and look a
bit deeper into their properties. We eat apples right down to the
core which gets discarded. Just as well as apple seeds contain
cyanogenic glycosides, a cyanide compound that could be fatal in high
enough doses, but that means eating an awful lot of apples in one
sitting. The potato and tomato belong to the solanacae family that
contains some very poisonous members including the deadly nightshade.
In the kitchen we all know to discard any potatoes where the skin has
turned green on exposure to light. It contains the toxin
glycoalkaloid solanine. This toxin is also present in tomato leaves,
stems and unripe fruits as well as tobacco and peppers. These
alkaloids in tobacco can be addictive and in belladonna fatal as it
contains tropane.
Winter garden |
Wee
jobs to do this week
The winter
garden has been the centre of attraction since early December once
all the leaves dropped
to the ground. Cornus, Kerria, Salix
Britzensis and the Japanese maple Acer Sangokaku have all got very
brightly coloured stems, adding winter colour up to the end of March.
However remove all the fallen leaves and any weeds that may spoil the
show. This also lets the early snowdrops grow up into the light to
add some colour contrast.
END