The importance of plants
In the developed world around a quarter of all prescriptions contain materials isolated from plants. Others, like aspirin, are synthesised copies of chemicals found naturally in plants, or are modified from the initial natural product.
Madagascar periwinkle (Catharanthus roseus) has yielded two drugs for the treatment of cancer: it is the source of alkaloids used to treat childhood leukaemia and Hodgkin's disease.
Medicinal plants are mostly harvested from the wild, which can put them under great pressure. In Europe alone, an estimated 150 medicinal plant species are at risk from over-harvesting.
Despite the high reliance on plants in medicine, less than 20% of the described plant species have been investigated for the presence of bioactive compounds. Many more medicines have yet to be developed from plant materials.
The importance of fungi
Fungi also provide extraordinarily powerful medicines that have revolutionised our health, with examples including antibiotics, immunosuppressants, and cholesterol medicine.