Information about toxic plants differs in degree according to location, proliferation and the potential dangers to humans, animals or wildlife in the environment. It is therefore important to study local conditions and relate to the plants that are proven to be hazardous in your area.
Many poisonous plants originate in the northern hemisphere and were inadvertently transported to colonial outposts in the southern regions. The native plants of the newly discovered worlds would have been less likely to demonstrate the process in reverse by increasing poisonous plant material to the northern regions although it must have occurred. But understandably, the introductions from the colonies and the newly discovered lands of the southern hemisphere to the north were mainly food items or plants of ornamental value.
With the study of indigenous plants increasing in modern times, there is a likelihood that much more information will be available in the future, but for the time being we must accept that the traditional plants of European and American origin that are known to be toxic are likely to remain as hazardous plants in their new status as introduced species in the countries such as South America, Africa and Australia. More information will be added resulting from our continued investigation and increasing knowledge of all plants of our world.
There is a need to warn of any dangers of certain plants that may be injurious upon human and animal health and well being, whatever their original habitat. It is interesting to note that many plants when introduced into a new environment reproduce very successfully and sometimes to the extent as to become a pest in their new country, although relatively controlled in their original habitat.
Any information about toxic nature of the poisonous plants given in this site is presented with a reminder to the reader that many of these plants also have a medicinal potential. There are many plants that have both a potential for toxicity and are listed also as medicinal plants. It is a matter of wisdom and professional skill in application or in prescribing any therapeutic substance whether it is more recently manufactured drug or a traditional herbal medicine.
There is a factor that should be considered as an important difference between the old and the new medicines. Modern medical science extracts from a plant source what are considered to the vital 'active' ingredients or chemicals that are then replicated in laboratories on a wide scale. Traditionally, the philosophy of herbalism focuses upon providing the whole plant or its part, as nature's chemistry created it.
Whereas some scientists consider we have made a progressive step forward in utilizing the capacity to analyze nature's plant compositions with the skill to isolate certain powerful chemicals it is not without its dangers as shown by the negative side effects that accompanies the history of each and every drug manufactured in this way.
A safer route is to depend upon the philosophy that 'Nature Knows Best' and remain faithful to the ancient wisdom that directs us to take a broader and inclusive view and to use the fruits and herbs of the Earth as our natural medicines.
Regarding our knowledge and interest in plants, we all have a responsibility to employ the health building plant foods in our nutrition as well as being aware of any precautions or potential dangers in plants that may threaten our children, our pets or ourselves and intelligently take steps to reduce the latter.