The greatest revenue derived from plants for medicinal purposes is derived from the roots, yet there are certain ones where the leaves and bark are used. Therefore to be complete some space is given to these plants. The digging of the roots, of course, destroys the plant as well as does the peeling of the bark, while leaves secured is clear gain — in other words, if gathered when matured the plant or shrub is not injured and will produce leaves each year.
The amount of root drugs used for medicinal purposes will increase as the medical profession is using of them more and more. Again the number of people in the world is rapidly increasing while the forests (the natural home of root drugs) are becoming less each year. This shows that growers of medicinal roots will find a larger market in the future than in the past.