The cowboys and farmers who go in the jungle know different herbs and plants.
A doctor must visit the jungle and find different plants and test their usage, ask their name from the locals.
Testing the herbs
But one cannot understand the qualities of a herb just by its knowing name and shape. In short, a doctor must test the herb in different situation and ailments to understand its qualities.
The doctor who knows the name, shape and qualities of herbs/medicines is known as tatwagya (one with supreme knowledge)
The doctor who customize the treatment according to the person's age, the place where he lives, quality of the medicine available and forumaltes a good treatment plan is the best doctor.
A wise doctor must not only know about the medicine name, shape but also their correct usage.