Herb seeds have been discovered in late stone age settlements, and the Chinese described medicinal plants and herbs from as early as 3000 BC - that's five thousand years ago. We probably owe our very survival in no mean part to the knowledge base of advice and information about herbs that was built up thousands of years ago. Much of that herbal advice and information has been preserved by folklore and written word over the centuries.
Herbs were in use even before our own history started! In historical France for instance, as long ago as 13,000 BC, cave paintings have depicted the use of 'plants - herbs' for healing purposes!
These types of historical findings are not exclusive to France. Plants on all continents have been used by the indigenous people for healing and other 'medicinal' purposes. They have also been used for non-helpful purposes as well! There is a great database of the historical use of herbs.
Over the centuries, a small base of knowledge would have been acquired within early tribal communities - mainly through trial and error. It is fair to assume that those trials were not carried out under laboratory conditions, and errors would have been observed quite dramatically!
As with all things historical, someone would have jumped on the bandwagon and assumed the role of Herbalist. Not many would have dared to 'argue' against the role of this person - as has often been noted by the respect shown to witchdoctors.
Most tribes on most continents seemed to follow this hierarchal route. There are ample research results to show the historical uses of herb throughout Europe and other continents. Different names perhaps - but usually the same respect and standing within the tribal community!
There is an almost limitless ability with plants for the synthesizing of aromatic substances. Many of these would have been produced to act as predator deterrents - against herbivores (Plant Eaters) and also micro organisms of differing types.
Many of the herbs and spices used by us as food seasonings contain useful medicinal compounds. Interestingly, they are used in small quantities, and do not really form part of the nutritional value of such treated foods.
The search for drugs and dietary supplements which are derived from plants have accelerated in recent years. The Earth is being scoured by many differing types of scientists and pharmacologists, in an attempt to find even more leads as to compounds that can be used to treat all sorts of ailments. Many of today's medical drugs have been derived from plants.
In many non-industrial countries, plants are still the most important route to treating all types of diseases. Plants are particularly useful in treating the natural disease - rather than the 'man-made diseases.