Yesterday’s meeting was all about plants that are irritants and plants that are poisonous. There are so many poisonous plants, only a handful are discussed below. I’ve started with the most common poisonous plant family.
Solanaceae - Potato Family
Solanaceae - Potato Family
The most well known plants in
this family are potatoes, tomatoes,
peppers, aubergines, chillies, pepinos and cape gooseberries, but it includes
some wild flowers and ornamental shrubs.
In general, in the Solanaceae
family the green parts and unripe fruit are poisonous to humans, not
necessarily to animals.
Symptoms occur 6-12 hours
after ingestion, fever, sweating, vomiting, abdominal pain, diarrhoea,
confusion and drowsiness. Children have
died from eating the unripe berries.
Solanum tuberosum - Potatoes -
were introduced into Europe in the 16th century by the Spanish. It took a while to become the staple it is
today. Initially people did not know
what part of the plant to eat. Mistakes
were made, some ate the stems and leaves.
The stems, leaves and the green on a potato are poisonous, they contain 'solanine' a glycoalkaloid that
could cause death after a period of weakness and confusion, followed by a
coma. With better information the
popularity of potatoes increased. Nowadays potato poisoning is a rare
occurrence. If it occurs, it is by eating
green potatoes or drinking potato leaf tea.
Tomatoes –
the leaves and stem of the tomato contain 'solanine' the same as in potato.
Solanum nigrum - Black
Nightshade –Morelle noire -Zwarte
Nachtschade
A common weed. The black berries contain 'solanine' again the same active ingredient as
in potato. This plant is sometimes confused with Atropa belladonna as both
have black berries. Solanum nigrum berries
grow in bunches, Atropa belladonna berries are solitary.
Solanum dulcamara -
Bittersweet - Douce-amère - Bitterzoet
Bittersweet is a climber, has
purple flowers and bright red berries. Same alkaloids as in potatoes and as in Black
Nightshade. Again poisoning is mostly by
ingesting berries. The name comes from
the taste, it tastes first bitter and then sweet. Children have died from eating Bittersweet,
but not many as the initial taste puts them off.
The next 4 mentioned plants, Atrope belladonna, Hyoscyamus niger, Mandragora autumnal is and Datura stramonium all contain in more or lesser degree the active ingredients, 'hyoscyamine, scopolamine and atropine'. Dature stramonium being the most potent.
Atropa belladonna - Belladonna or Deadly Nightshade – Belladone - Wolfskers
A plant still used
today. Its main active ingredient is ‘atropine’ used by eye specialists to dilate the pupils and to
temporarily paralyse the muscles that help the eyes to focus. The leaves and roots have sedative and
calming properties. First they stimulate the
central nervous system, then they suppress it.
Used as well for breathing problems, rheumatism, muscle ache and stomach
cramps.
Hyoscyamus niger – Henbane – La
jusquiame noire –Bilzekruid
Henbane acts calming, as a
painkiller and against cramps. The smell is enough to cause giddiness and
stupor.
Mandragora autumnalis – Mandrake –
La mandragore – Alruin
It was once used in magical
and orgiastic rituals. Tea made from the
roots or leaves causes first excitement then numbness, hence being used in
magical and orgiastic rituals. In
Homeopathy it is used for astma and cough.
Datura stramonium – Datura –
Doornappel.
Even picking the leaves can
cause symptoms in certain people.
Picking leaves was done commercially for the pharmaceutical industry in
the first half of the 20th century. It was used to relieve spasms
of the bronchioles during astma. Some of
the pickers experienced impaired vision followed by eye infection.
All these 4 above mentioned plants contain hallucinogenic compounds. By smearing the ointment on certain places,
under the armpits or on the vagina, the hallucinogenic effect worked fast, much
faster than ingesting it, and in addition it would avoid intestinal discomfort
and the effect was stronger as it was not partially broken down by the liver.
The idea they were flying on a broomstick comes from using these drugs.
Sambucus nigrum – Elderberry - Sureau - Vlierbes
The flowers and berries are edible, but the roots and the leaves are poisonous and will cause severe stomach problems.
The flowers and berries are edible, but the roots and the leaves are poisonous and will cause severe stomach problems.
Ricinus communis – Castor Oil Plant - Ricin - Wonderboom
It belongs to the Euphorbia family. The seeds (40-60% oil) produce the castor oil. Castor oil was widely used as motor oil, now mostly replaced by synthetic oils. Internally it was used for constipation.
It belongs to the Euphorbia family. The seeds (40-60% oil) produce the castor oil. Castor oil was widely used as motor oil, now mostly replaced by synthetic oils. Internally it was used for constipation.
The plant is considered one
of the most poisonous plant in the world, 4-8 seeds is enough to kill an
adult. It is not a poison that is used
in suicides because of painful and unpleasant symptoms – it causes nausea,
severe vomiting, convulsions and then disintegration of kidneys, liver and
spleen. These symptoms can take up to a week.
The principal poison in the
castor oil plant is called ‘ricin’. The workers who collect the seeds work by
strict safety guidelines to prevent accidental death.
Castor oil seeds are easy to
procure, and in the form of purified ‘ricin’
could be used as a terrorist weapon, e.g. added to food and beverages. It is not
destroyed by heat, and potentially could be added to an explosive device.
The political assassination
in London of Georgi Markov, a broadcaster and journalist for BBC World Service was
carried out by using the tip of an umbrella.
A micro-engineered pellet containing ricin was fired into Markov’s
leg. It took 4 days before he died of
gastroenteritis and organ failure.
The greatest concerns are
that the symptoms are misdiagnosed.
Commercially bought cold
pressed castor oil is not toxic, internally or externally.
Cyanide
Cyanide is a
quick acting poison. Zyklon B (brand
name), a gas with as its main component
‘hydrogen cyanide’ HCN (prussic
acid – acide prussic - blauwzuur) was used in the death camps during World
War II. Ironically it was developed by
Fritz Haber, a German Jew.
Stories abound of spies or
criminals, biting into cyanide tablets and dying very quickly. During fires, burning plastic and polystyrene
foam give off cyanide gases.
Hydrogen cyanide is synthesized through a variety of chemical processes. It is used in industry in explosives, engraving
and dyeing processes and was used in vermin and insect poison.
The effect of poisoning by
Hydrogen cyanide restricts oxygen intake and causes suffocation.
Lots of plants contain hydrogen cyanide (prussic acid) in
smaller or larger doses.
Prunus amygdalis var. amara - Bitter Almond
There are two types of almonds, sweet almonds and bitter almonds. Bitter almonds, because of their flavour are used for culinary purposes. Unfortunately raw nuts contain ‘prussic acid’. Before consumption, bitter almonds must be processed to remove the poison. Heat destroys the poison.
There are two types of almonds, sweet almonds and bitter almonds. Bitter almonds, because of their flavour are used for culinary purposes. Unfortunately raw nuts contain ‘prussic acid’. Before consumption, bitter almonds must be processed to remove the poison. Heat destroys the poison.
Cherries –
Cherries belong to the same family as plums,
apricot and peaches. All these
fruits contain poisonous compounds in their leaves and seeds. Almonds are a member of the same family but
they are the only fruit that is harvested for their seeds rather than their
fruit. When the seeds of the cherry are
crushed, chewed, or even slightly injured, they produce 'prussic acid (hydrogen cyanide)'.
Apples –
Like the almonds and the cherries, apples contain prussic acid, but in much smaller doses. Apple seeds are very often eaten by accident,
but you would have to chew quite a few to have any symptoms.
Exposure to low levels of cyanide over long periods, e.g. after
use of Cassava roots as a primary
food source as is done in tropical Africa, results in weakness, paralysis and
mild liver and kidney damage.
Rhubarb – Rhubarbe - Rabarber
The leaves are poisonous, in addition to the poison they contain a corrosive acid. The stems are edible and the roots have been used for centuries as a laxative.
The leaves are poisonous, in addition to the poison they contain a corrosive acid. The stems are edible and the roots have been used for centuries as a laxative.
Aconitum napellus – Monkshood
– Aconit napel - Monnikskap
Another very poisonous plant. All parts are poisonous, but the roots
contain the most poison.
Spears and arrows were coated
with the poison and in Roman times it was used to eliminate criminals and
enemies. Later it was banned and if
anyone was discovered growing Aconitum, they were sentenced to
death.
It works on the
cardiovascular and central nervous system.
It reduces fever, has painkilling and calming properties. Once used internally now only externally for
rheumatism, neuralgia and sciatica or in homeopathic medicine.
Care should be taken by
wearing gloves when handling the plant. Aconite poisoning has been described as:
“Burning of mouth, constriction and pain in throat and chest, greatly laboured
breathing, vertigo, diminished vision or blindness, slight convulsive twitching
and a sense of impending doom. It leaves no traces.
Digitalis purpurea – Foxglove – Digitale pourpre - Vingerhoedskruid
Digitalis lanata – Woolly Foxglove – Digitale laineux - Wollig
Vingherhoedskruid
Digitalis lutea – Yellow Foxglove – Digitale à petites fleurs -Geel Vingerhoedskruid
It was William Withering who
discovered the uses of Foxglove to treat dropsy (oedema). He published his findings in 1768. He was a young country doctor who in his
capacity as doctor visited a young women who was bedridden. This lady, as a hobby, painted plants and
flowers. He was attracted to her and to
please her, as she was unable to leave the bed, he would collect wild plants
for her. He became interested in the
plants he collected and the more he learned about them, the more he realised
the possible medical potential of some plants. He was particularly interested in the
Foxglove. He read all the papers
available on Foxglove and decided it needed further examining. He married the young lady and set up a
practice in Bristol. At the same time he
opened a clinic for the poor, so he had ample patients to try out his
experiments. He decided to use the leaves when the plant was in flower just
before setting seed, before or after would give different levels of active
ingredients. It turned out to be an
effective medicine to treat dropsy (fluid retention in the
connective tissue of the body) often caused by heart problems.
During William Withering’s
days Digitalis purpurea was used, the active ingredient 'digitoxin' was effective
but the toxin accumulated in the liver.
Today, Digitalis lanata is
used. The active ingredient is different from D. purpurea, is called 'Digoxin' It is used to treat
several heart conditions. It increases
the contractions of the heart without using more oxygen, and regulates the
heartbeat. Digitalis lanata works 4 x
stronger than Digitalis purpurea.
Fatal accidents have occurred
but are rare, i.e. children drinking from a vase with Digitalis flowers or if
it is confused with Symphytum officinale (Comfrey – Consoude - Smeerwortel).
Conium maculatum – Poison Hemlock – Ciguë tachetée - Gevlekte Scheerling
Conium maculatum – Poison Hemlock – Ciguë tachetée - Gevlekte Scheerling
Hemlock was used by the
ancient Greek State as a death sentence. The accused had to drink a cup of
Hemlock.
It was the poison given
to the philosopher ‘Socrates’. How
poisonous it is varies greatly, it is supposed to be far more poisonous in hot
Mediterranean climates than in northern climates, but should always be treated
with caution.
It belongs to the Carrot
family (Umbelliferae) and as such looks quite similar to many of the other
plants in the family. Nature’s way of
warning you that something is wrong is its foetid, unpleasant smell and a very
sharp taste. The stem is hollow and covered
in brownish-red spots.
Deaths have occurred by incorrectly
identifying the plant and mixing it up with other Umbelliferea.
It is a biennial and in its
first year looks remarkably like parsley.
The seeds are the most poisonous part.
It attacks the peripheral nervous system. Formerly used in epilepsy,
mania, cramp and astma.
In excess – difficulty in
breathing, paralysis, stupor and finally death.
Plato describes Socrates’s
death as: "a slow ascending paralysis,
beginning in Socates’ feet and creeping steadily up his legs towards his chest,
with Socrates’ mind remaining clear until the end. Death arrives calmly and peacefully" unquote. (Journal of the International Plato Society).
Taxus baccata – Yew – If - Taxus of Venijnboom
All parts of the shrub/tree are
poisonous, except for the fruit when the pip has been taken out. It contains a chemical ‘taxotere’, which is
used in the treatment of breast, ovarian and prostate cancer. Taxus clippings are collected in several
countries, as part of the process of making ‘taxotere’. Taxotere interferes
with cell division.
Nerium oleander – Oleander
A very common plant in our area, deaths occur if the wood is used for cooking purposes and dogs biting into the branches.
A very common plant in our area, deaths occur if the wood is used for cooking purposes and dogs biting into the branches.
Some of Wellington’s men in
the Peninsular War of 1807-14 are said to have died after eating meat cooked on
skewers made from oleander. It contains
cardiac glycosides, the poison attacks the stomach, heart and central nervous
system causing drowsiness, tremors,
seizures, collapse, coma that can lead to death.
The sap if in contact with
the skin can cause blistering, irritation and soreness, but nothing else.
Never burn oleander branches,
inhalation of burning oleander can cause in varying degree the symptoms of
oleander poisoning.
Some poisonous plants originating from outside Europe
Strychnos nux-vomica and Strychnos ignatii
One of the most well known
poisons must be ‘strychnine’. There are 196 species of trees and climbers
in Asia, America and Africa that have the component ‘strychnine’ in their seeds or bark.
In general ‘strychnine’ comes from the Strychnos
nux-vomica tree from Asia. A 12
m tall tree with orange fruits the size of apples, each fruit contains 5 seeds. The other tree is Strychnos ignatii from the Philippines and China.
'Strychnine'
can be absorbed through ingestion, inhalation or by injection and is very
quickly absorbed. 50% of ingested ‘strychnine’ is absorbed and entered
into the tissues in 5 minutes. 60-100 mg
‘strychnine’ is fatal, 1-2
hours. It produces one of the most
dramatic and painful symptoms of toxic reaction.
In small quantities it has
been used as a performance enhancing drug.
It was used by athletes before testing came along.
In the 1992 Barcelona Olympics
a Chinese volleyball player was taking as a tonic, capsules that contained 'strychnine'. She was not aware what was in these
capsules. Although she was banned, no
blame was attached to her.
Apart from enhancing qualities it was mostly used to
kill vermin. As it is quite
indiscriminate, it could quite easily kill a cat or dog. It has now been banned to be used as a
pesticide in several countries.
Curare
Curare is a general name for
arrow poison used by the native population of Central and South America to kill
prey. The poison is derived from
different trees and climbers but principally from the Chondrodendron tomentosum
climber.
It produces a weakness in the
skeletal muscles, and in high enough doses, death by asphyxiation due to
paralysis of the diaphragm.
It’s muscle relaxing
properties were used from 1930’s during surgery. Nowadays it has been replaced by synthetic
drugs as the dosage is easier to establish.
It is harmless if taken internally as the compounds
of the drug are to large to pass through the lining of the digestive tract to
be absorbed into the bloodstream. For
the same reason the natives are able to eat the meat caught with the poisoned
arrow.
Catharanthus roseus – Rose Periwinkle – La pervenche de Madagascar – Roze
Maagdenpalm
From the Rose Periwinkle the
alkaloid ‘vincristine’ is extracted. It
is used in treatment of several cancers, specifically in the treatment of
childhood leukaemia and has contributed to the survival rate increase from less
than 10% in 1960’s to 90% today.
See Mavis’s article on Irritants.
For further reading access the poisonous plants website : thepoisongarden.co.uk
also, the poison garden at Alnwick Castle
Bibliography : Wikipedia; Encyclopedia of Herbs and their Uses - Deni Bown; Herbs and Herbalism - Malcolm Stuart
Photos: Web
For further reading access the poisonous plants website : thepoisongarden.co.uk
also, the poison garden at Alnwick Castle
Bibliography : Wikipedia; Encyclopedia of Herbs and their Uses - Deni Bown; Herbs and Herbalism - Malcolm Stuart
Photos: Web
