In ancient Indian literature, there is no single book containing information which can be called systematic, concise, covering all aspects of plant life with science behind it. Scholars spread in length and breadth of this country have contributed to information on diverse aspects of plants over a period from 1500 BC to 1500 AD and later also, making a mine of information available to the future generations. The beauty of this literature is that it passes the test of authenticity irrespective of place and time.
The sphere of biology encompasses firstly- botany and zoology, secondly- anthropology, and thirdly- anatomy and physiology. Botany is the science which treats only plants and includes information about their names, internal and external organization, anatomy, physiology, qualities, utilities, distribution on the earth surface, laws or parameters by which their growth and distribution is regulated or geological occurrences by which it has been brought about. Botany received momentum in the sixteenth century, mainly thorough the work of physicians and herbalist who started using plants for medicine. Today, the principle branches of botanical study are morphology, physiology, ecology and ethno botany, etc.
Application of these parameters of modern biology and botany to the ancient Indian literature which contains information about plants reveals that it was not less scientific than that provided by scholars of the West from sixteenth century onwards. In this regard it is noteworthy to mention Parashara’s Vrikshayurveda from first century BC. It is one of the earliest, may be the first, works dealing with plant life from a scientific point of view. Here in plants are classified into numerous families (ganas) on the basis of morphological features not known to the European classification until eighteenth century. He also referred to internal structure of the plant, for example, cell (rasakohika), chlorophyll (ranjakena pacyamanat). He also notes that the internal structure of the leaf consists of innumerable compartments which are filled with the sap. They are the storehouse of sap (rasasrayah) and covered by a boundary-cell wall or cell membrane (kalavestana). About the contribution of Parashara a quote by A. E. Radford (1986) systematist of USA is sufficient, who says that Parashara had some kind of hand lens or microscope.
Thus, it can be concluded that much before development of modern biology and botany in the Western world ancient Indians had already made contribution in the field of plant science which they called Vrikshayurveda.
Sanskrit word ayurveda is composed of ayur meaning ‘life’, and veda denoting ‘knowledge’ or ‘science.’ Thus, ayurveda exemplifies science of life, knowledge about life or sensible way of living or growing based on knowledge. The tree is known in Sanskrit as vriksh and ‘ayurveda’ is added as suffix to it; the new word becomes ‘Vrikshayurveda’. Applying the meaning of the term ayurveda to Vrikshayurveda, Vrikshayurveda becomes science of tree life, knowledge of tree life or sensible way of living or growing (trees) based on knowledge.
The survey of literature reveals that the term ‘Vrikshayurveda’ is being used in different context depending upon the necessity in different time periods. The term Vrikshayurveda first appeared in Kautilya’s Arthashastra in fourth century BC as ‘krishitantra-gulmavrikshsháyurveda’ where gulma refers to cluster of trees, bush, and shrub, etc. Arthashastra clearly talks about ‘Krishitantra’ that is agriculture, horticulture, irrigation and economic purposes and revenue aspects of agriculture enumerating the functions of the officer in charge of agriculture, and his assistants. In first century BC Parashara wrote treatise called Vrikshayurveda with details of botany. In sixth century AD Varahamihira in Brihat Samhita as well as Agni Punrana of 8th -9th century AD dedicated chapter to plant life with title Vrikshayurveda which deals with treatment of plant diseases and prescriptions of remedies and nutritional and other aspect of plant life. While Surapala’s Vrikshayurveda from 10th century provides excellent information on arbori-horticulture. Surapala being an Ayurveda scholar for the first time applied principles of Ayurveda to Vriksha. Soils, plant species, and kind of plant protection, nourishment material Surapala is referring reveals his main aim of growing healthy Ayurvedic medicinal plants required to cure human ailments.
Along with these survey of other ancient Indian literature about plants as well as undocumented knowledge about Vrikshayurveda utilized by tribal and farmers reveals that Vrikshayurveda can be studied from four points of views, namely, botany, medical science and agricultural science as well as information of tribal and farmers.