Every ethnic group has their own system of traditional medicine and make use ofnatural resources around their habitats for many medicinal purposes. This traditional erudition is bequeathed orally from one generation to the other through tribulation and error methods .Ethnobotany is mainly a part of taxonomy and floristic studies, the todays traditional medicine studies have advanced much and have developed into several subdisciplines.The introduction part has been divided and discussed into focusing upon the relevance and importance of both Ethnobotany and traditional taxonomy separately.
Harshberger applied the term ethnobotany ,a modern branch of science to the interrelationships between primitive humans and plants in 1896. Majority of the herbal drugs are raw plant drugs or their extracts primarily used by ethnic groups .The knowledge acquired by the tribal groups about the use of medicinal plants is declining day byday.It is therefore important that in future, a comprehensive ethnomedicobotanical inventory of the plants used by the ethnic people should be carried out regularly for the benefit of the public.
Ethnobotany gives an idea of wealth of traditional knowledge and also provide an indication to new or lesser known sources of medicine, food, fiber, fuel and other plant products (Jain and Mudgal, 1999). Traditional medicine in India consists of two categories viz., folk medicine and the codified systems of medicine such as Ayurveda, Unani and Siddha. The earliest reference of the medicinal use of plants and animals in human civilization can be traced back to the Vedic period. The \'Rigveda\' (4500-1600 BC) is the ancient source of human knowledge on medicinal plants.
Ayurveda is one of the oldest and tradition-al medical systems available on the world today. India is one of the 12 mega diversity centers rich in biological diversity in the world, and it is the hosting about 49,219 species of plants, 17,500 angiosperms, 64 gymnos-perms, 1,100 pteridophytes, 2,850 bryophytes, 6,500 algae, 14,500 fungi and 2000 lichens etc. Of these, about 5000 angiosperms are endemic (Jain, 2000).
The presence of diversified living ethnic groups and rich biological resources make India one of the richest countries in ethnobotanical knowledge, with about one million traditional village based herbal practitioners (Shankar, 1999). Ethnobotanical surveys are essential steps in the identification, selection and development of therapeutic agents from ethnomedicinal plants which serve as a basis for new compounds with active principles for phytochemical, pharmacological and clinical research purposes. Now a days, the whole world is looking for plant based remedies for safe and effective cure of dangerous human diseases. Trichopus zeylanicus was recen-tlydiscovered by scientists of Tropical Botanical Garden and Research Institute (TBGRl) at Thiruvananthapu-ram, Kerala is another example of harvesting and promoting the traditional knowledge of tribal people of India (Mashelkar, 2001). A detailed ethnobotanical study may not only draw the attention of phytochemists and pharmacologists but also help to transmit and conserve the knowledge of plant remedies that are passed on from generation to generation.
Due to the unavailability of modem primary healthcare facilities as well as their distant location, they have learned to use local plant species to treat different ailments after centuries of trials, quite often at the risk of the loss of life. During the last two decades, following the understanding of the widespread toxicity and harmful aftereffects associated with the longtime use of synthetic drugs, the whole world prefers herbaldrugs from natu-ral sources to the synthetics. Hence, there is greater demand for plant derived drugs and pharmaceuticals in the world market. The World Health Organization (WHO) currently recommend and encourage traditional herbal remedies in natural healthcare programs since these drugs are easily available at cheap cost and are compara-tively safe. Approximately 2,50,000 to 7,50,000 species of flowering plants exist on earth; some of them have not yet been botanically described. The WHO indicates that of the 35,000-70,000 species of plants that are used for medicinal purposes around the world, about 5000 have been submitted to biomedical scrutiny..
The most useful strategy is to carry out multidisciplinary research on the development of drugs from plants, a task that can only be effectively through collaboration between botanists, ethnobotanists, pharmacognosists, phytochemists, biologists, pharmacologists etc..As a result of their longterm use, traditional medicines, including folklore remedies, are generally considered to be safe and medically suitable, and as such have been the proven and reliable source of active phytochemical compounds. Largescale studies examining the potential of medicinal plants have reported a high correlation between the traditional use of plants and the existence of active compounds within the plant extract (Palombo and Semple, 2001; McRae et al., 2007).
Screening of the crude extract of different medicinalplants assist the presence of bi ologically active compounds and therefore validates the use of such plants in traditional medicines (Palombo and Semple, 2001). Numerous herbal drugs have entered the international Pharmacopeia through the study of Ethnobotany. presently, at least 119 lively compounds, derived from 90 plant species, can be considered as essential tablets which might be in use in many countries. Of the 119 drugs, 74 % have been determined as a result of chemical research directed at the isolation of the energetic materials from plants utilized in conventional medicinal drug (Fabricant and Fams-well worth, 2001; Newman et al., 2000).
The present century has witnessed the emergence of ethnobotany as a distinct academic branch of natural sciences. All over the world, there has been an increase in the scientific study of man and plant interaction in natural environment among various indigenous people. \n\n
The documentation of indigenous knowledge on medicinal plants is important for value addition and upliftment and poverty alleviation of local communities and tribal people. Population pressure and other anthropogenic activities causing a great deal of habitat loss and species extinction in every part of the world. As a result, the number of plant species are becoming vulnerable and are facing danger. Today, biodiversity dependent tribal populations are facing a serious threat because of the rapid loss of natural habitat and the overexploitation of medicinal plants from the wild .Due to industrialization, expansion of agricultural land and urban areas, forest laws and unemployment, the ethnic communities are moving toward urban areas. Many of them are unaware of their rich wealth and traditional knowledge of plants. With the rapid industrialization of the earth and the loss of ethnic cultures and customs, some of this valuable information will disappear very soon. Consequently, there is an urgent need to record and preserve all information on plants used by different tribal communities, living throughout the world, for different purposes before it is completely lost. A systematic literature survey sug-gested that significant ethnic knowledge in India is documented (Nayak et al., 2004)