Beautiful but poisonous plants in Tenerife

A great part of the beauty of Tenerife is created by the amazing wealth of exotic plant species that grow on the island. There are, however, many common ones that are definitely the "femme fatales" of the vegetable kingdom. In other words they are very beautiful to look at but can be deadly if eaten.

Surprisingly many very toxic plants are grown in flower borders and in gardens and parks. This is in sharp contrast to the UK where much-publicised campaigns have been held via the media about dangerous plants such as the Laburnum tree, in which warnings were issued that a few seeds could kill a child.

On Tenerife the authorities do not seem to worry about such matters, and with good reason because no one seems to come to any harm. Nevertheless it is always a good idea to know what plants are potentially dangerous.

Oleander

One of the most commonly seen flowering plants that is very poisonous is the Oleander (Nerium oleander ). With its showy bright pink or white flowers that grow in clusters the Oleander forms large bushes in many borders along roads and in parks and gardens. It is a very popular flowering shrub to grow but is also very poisonous.

Castor Oil Plant

The Castor Oil Plant (Ricinus communis ) has attractive large palmate leaves in green, bronze or reddish colouring and strange-looking flowering spikes. Although it is not a native to the Canary Islands and is grown as an ornamental plant it has spread as an invasive weed of waste ground and roadsides and just about anywhere its seeds end up.

It is grown commercially for its oil but the poison ricine contained in its seeds is regarded as one of the most dangerous toxins produced by plants. One of these beans can kill if eaten.

The Castor Oil Plant is a member of the spurge family or Euphorbiaceae, although it doesn't look much like others in this group. The other Euphorbias are mainly poisonous plants too and most have a milky white latex.

Cardón

There are several endemic species such as the Cardón (Euphorbia canariensis ) that many people think is a cactus because of its thick columnar leafless stems that have spìnes along their edges and which grow in clumps on the semi-desert areas and on mountains and cliffs.

The "Tabaibas" (Spanish for spurge) such as E. broussonetii and E.atropurpurea are succulent shrubs that are commonly seen growing in large patches. Like the Cardón they have a white millky juice if cut or broken and this is toxic and burns the skin.

Poinsettia

The attractive Poinsettia (E.pulcherrima ) with its bright red bracts around the tiny flowers grows well on Tenerife and blooms in winter. It gets used a lot at Christmas time where it brightens up many flower borders as well as growing as large bushes along roadsides and in gardens. The Poinsettia is one of the many plants in this large family that are not native to the island but are grown for their ornamental value.

Carissa

The Carissa (Carissa spectabilis ) is a small tree or very large evergreen bush. It has bunches of small white strongly-perfumed flowers that are followed by black fruit like small plums. Don't eat them though because they are poisonous. The Carissa is often planted in shrub orders and in gardens and parks around Tenerife.

Angel's Trumpet

Also planted in these locations around the island are the Angel's Trumpets or Brugmansia species. They grow as small trees and have very large funnel-shaped flowers, which in some types give out a strong perfume at night. Brugmansia x versicolor has salmon-pink to peach-coloured flowers, and B x candida has white blossoms.

The species B. sanguinea has red and yellow flowers, and coming from the Andes, does better in cooler parts of the island. It is grown in parts of the north of Tenerife and in the gardens of towns and villages in the mountains.

All of the Angel's Trumpet species contain several poisonous alkaloids which are hallucinogenic and have been used by shamans in Central and South America where the plants originate. It is a very risky business though consuming these plants because they can easily kill if you take too much.

Datura

The Brugmansias are very closely related to the Datura or Thorn-apple species, of which D. metel and D. stramonium are often seen growing as weeds along roadsides, on waste ground and newly turned soil. Like the Angel's Trumpets they are very poisonous.

Wikipedia tells us: "Datura metel may be toxic if ingested in any quantity, symptomatically expressed as flushed skin, headaches, hallucinations, and possibly convulsions or even acoma. The principal toxic elements are tropane alkaloids. Accidentally (or intentionally) ingesting even a single leaf could lead to severe side effects."

Hemlock

Another wild plant that is very poisonous is the Hemlock (Conium maculatum ). It bears umbels of whitish flowers and has attractive feathery leaves. It is easy to mistake for other plants in the Parsley family (Apiaceae ) but fortunately it has a warning sign because the stems are marked with dark purplish flecks and spots. Hemlock grows in waste places and can form large clumps.

Henbane

One more very toxic plant that grows as a weed is the Henbane (Hyoscyamus niger ). Henbane is often found along sea fronts on waste ground and in flower borders and anywhere its seeds may have fallen. It has attractive pale yellow flowers marked with purple veining that produce hundreds of seeds that are housed in curious-shaped seed pods that form along the stems after flowering.

Tree Tobacco

Another poisonous plant that grows as an invasive weed on Tenerife is the Tree Tobacco (Nicotinia glauca ). Also known as the Mustard Tree and as "Bobo" in Spanish it grows into a small tree with large greyish green leaves and bunches of small yellow tubular flowers.

Tree Tobacco has spread around many sub-tropical and tropical parts of the world and easily establishes itself along roads and on waste ground and abandoned farmland.

Although related to the Tobacco Plant it contains very little nicotine and is of no use to smokers, although, interestingly, it has been used in trials to wean people off the habit. Tree Tobacco contains a poisonous insecticide known as anabasine.

Copyright © 2012 Steve Andrews. All Rights Reserved.