The term herb has usually been used to refer to any plant or plant part valued for it's medicinal, savory, or aromatic qualities. For the purposes of this book, herb means any plant that is primarily used for medicinal purposes.
There are approximately 380,000 species of plants on earth that we have identified and several hundred thousand that have yet to be discovered. (Right now, many scientists are desperately trying to catalogue the plants in the Amazon rain-forest in the belief that there are thousands of potential plant cures that are rapidly being destroyed by development. ) Out of the number of known plants, about 260,000 are classified as higher plants, which means that they contain chlorophyll and perform a process called photosynthesis. In photosynthesis, plants utilize the energy provided by sunlight to manufacture carbohydrates from carbon dioxide and water. All the members of the higher plant group have the potential to offer medical benefits. Only 10 percent, however, have actually been studied for this purpose.
In the Herb Bible, I refer to each herb by its two names: the familiar name by which it is commonly known and a Latin botanical name describing its genus and species. The genus or first name is the general grouping of plants by family. Although plants in a given genus are not identical, they have in common certain similar characteristics. The species is a more specific way of defining each plant's distinctive qualities. For example, onions, garlic, and chive are all members of the Allium genus. However, each of these herbs is classified as a different species.
