Parts of the Plant to be used, Nomenclature, Drug Acquisition and Preservation

Herbal medicines are obtained from either wild or cultivated plants with economic factors usually determining the choice. It may be more advisable to obtain the drug from wild plants which are particularly common, therefore limiting the costs; however, scarcity and consequently high costs of wild plants make cultivation a valid alternative. Dioscorea (Dioscorea mexicana) and cascara (Rhamnus purshiana) are almost exclusively obtained from wild plants in Mexico and the United States, while in Europe foxglove (Digitalis purpurea) is obtained from cultivated plants. Marshmallow (Althea officinalis) is obtained from both wild and cultivated plants in Europe. Without doubt cultivation offers many advantages: the main is the possibility to have plants with a constant chemical composition.