By Jean-Jacques Segalen (jjacques) October 26, 2010
The plant kingdom does offer a great many delicious tastes but some can prove to be final…as a matter of fact many species which look pleasant and may even produce nice colours and perfumes can have highly destructive effects if ingested or even slightly touched and this concerns quite a few common plants.
(Editor's Note: This article was originally published on April 27, 2008. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
A common trait amongst the Solanaceae family is they often bear alkaloids - big, toxic molecules. Many gardens host the wonderful free-flowering and strongly scented Brugmansia (often called erroneously Datura as they are closely related but belong to a different genus). The whole plant contains alkaloids derivative of a tropane basis, mainly hyoscyamine, atropine and scopolamine, the seeds being the richer part. Although the leaves are sometimes smoked to treat asthma they may lead to severe intoxication leading to vertigo, drowsiness, mydriasis, tachycardia, hallucinations, respiratory paralysis and then death...this plant is actually used in many countries as intoxicant and poison. The true Datura which are not usually grown in garden but very often seen on rubbles and refuses are just as dangerous and used by criminals in India to poison innocent travellers so as to rob them and are an important part of the beverage used in Haiti to produce the zombie phenomena. Another member of this botanical family which is quite often seen in tropical gardens is the Solandra nitida or chalice vine, a powerful climber with enormous yellow flowers giving off a coconut perfume. The whole plant is full of solandrine which is very similar to atropine and will lead to digestive troubles, nauseas, vomiting, mouth dryness, diarrhoea, delirium, convulsion and coma...
An even more common species as it is found not only in private gardens and public parks but also grown along roadsides, the rose-bay (Nerium oleander) belongs to the Apocynaceae family and is extremely poisonous in all of its parts. It produces cardiac glycosides such asoleandroside, nerioside and neriantoside which are all related to digitaline found in foxgloves. Chewing the leaves will induce vomiting, belly aches, heart troubles and often will lead to death. I had the chance (if one can say!) to personally experiment such intoxication while I travelled in Greece and inhaled smoke from a fire where stumps and branches of the oleander had been thoughtlessly tossed, I hadto lay flat for 24 hours and felt very ill. For those of the readers who are into historical stuff let them remember the many deaths of Napoleon soldiers who invaded Egypt and died after using oleander branches as skewers. A tea made with the leaves and used as abortive has led to many a death in Africa.
Another favourite in tropical gardens and amongst enthusiasts is the Anthurium, one of the numerous genus of the Araceae family. This very decorative plant much used for bouquets contains saponins and calcium oxalate crystals, even a small piece brought to the mouth will almost immediately provoke a swelling of the throat which will soon bring death by the mean of suffocation. Sensitive people will even get itching and burnt-like reaction when sap comes in contact with the skin. Another member of the Araceae quite often used as indoor plant has the same properties, the Dieffenbachia has been called ‘dumb-cane' and one will easily understand why.
After this little garden tour which should make some of your hair stand on end we will continue by venturing into gullies and fallows, good places to find all sorts of witchy accessories...Here we will soon find castor oil plant, Ricinus communis which is a common sight on Reunion, a handsome plant with large palmate leaves. The weapon here is hidden in the seeds as contains a deadly phytotoxin called ricin. Fifteen seeds will be enough to kill a grown up while two or three of the same seeds will have the same result for a child. The effects are burning of the mouth, throat, abdomen, strong vomiting, intense thirst, bloody diarrhoeas, sight troubles, fainting and death. This frightening member of the Euphorbiaceae family is found in many places as it has, and still is to some extent, been used to produce oil.
Let us stay in this ravine bottom and get closer to a small vine nicely ornate by clusters of dry fruits which are full of shiny seeds half red and half black, very attractive indeed! This is the rosary pea of jequirity, Abrus precatorius. Do not be afraid here, you can touch the seeds, smell them, lick them, even put them in the mouth and swallow, it will go through your digestive track and come out as the very hard coat will protect it against gastric juices. But to be honest I would not recommend doing this because it would suffice that the seed has a crack or that you would break it with your teeth and this would bring an especially horrible end; the abrine contained by the seed would slowly be released in your body and after a few hours or days would start to agglutinate your red corpuscles, leading to intense headaches, hypotension, multiple haemorrhages (mostly digestive system and retina), possibly hallucinations, delirium and convulsions, a whole firework you do not really want to experiment. This rather common plant in dry tropical areas is very often used to make collars and other ornaments but just one or two seeds falling accidentally from the cook's neck in the cooking pot will make it the last meal for many a guest. Actually the lethal dose in half a seed for an adult, and those are tiny seeds.
In order to finish off the few surviving readers we will now consider a nice yellow flower also quite common in the dry tropics, the spiny poppy or chicalote. Argemone mexicana as you can guess from the name comes from Mexico and belongs to the Papaveraceae family, famous for the poppy, another strong poison. This poppy is full of alkaloids (of course!) of the isoquinoelein type; protropin, berberin. Here the seeds are also the main responsible for legs oedemas, general aches, diarrhoeas, dyspnea (troubles breathing), heart insufficiency, anemia.
I hope this article did not terrify you but a warned gardener is worth two, avoid tasting what you do not know. What about a little seed brunch with me now? Sure you don't want?
About Jean-Jacques Segalen
I am a Parisian born professional horticulturist specialized in tropical seeds producing, living on Reunion island (just between Mauritius and Madagascar) since 20 years . I spend a lot of time gathering seeds in the wild, the ones I do not grow that is. Also a dedicated Tai-Chi practitioner and fully certified arborist-tree surgeon
Just released my first book on tropical plants and fruits, check it at http://www.barbadine.com/pages/livrejjGB.html