Herbal medicine is the study of botany and the use of medicinal plants. Plants have been the basis for medical treatments through much of human history and such traditional medicine is still widely practiced today. Modern medicine makes use of many plant-derived compounds as the basis for evidence-based pharmaceutical drugs. Although herbalism may apply modern standards of effectiveness testing to herbs and medicines derived from natural sources few high-quality clinical trials and standards for purity or dosage exist. The scope of herbal medicine is sometimes extended to include fungal and bee products as well as minerals, shells and certain animal parts.