Medicinal plants have played an essential role in the development of
human culture, for example religions and different ceremonies. Medicinal
plants are resources of new drugs. It is estimated there are more than
250, 000 flower plant species. Plants are directly used as medicines by
a majority of cultures around the world, for example Chinese medicine
and Indian medicine. Medicinal herb can be a real herbal plant, a shrub,
other woody plant, or a fungus. The used part may be the seeds, berries,
leaves, barks, roots, fruits, or other parts of a plants, or mushroom,
which may be considered "herbs" in medicinal or spiritual use. Many of
the modern medicines are produced indirectly from medicinal plants, for
example aspirin. The botanical survey of India has prepared a
provisional list of threatened plants which includes large number wild
(or) wild relatives of food, horticultural, Medicinal and aromatic
plants. In India, Ayurveda (developed in North India), Siddha (developed
in Tamil Nadu) and Nagarjuna (developed in Andhra Pradesh) systems of
medicine were developed. Ayurveda is practiced in SriLanka, Pakistan and
Bangladesh also.