Large number of medicinal plants are at risk of extinction, and could spark a global health crisis, according to experts.
Scientists have warned that the plants' disappearance might threaten the discovery of future cures for diseases.
Researchers say that the cures for diseases such as cancer and HIV may become "extinct before they are ever found".
The team, which represents botanic gardens across 120 countries, surveyed over 600 of its members as well as leading university experts.
They identified 400 plants that were at risk of extinction. The plants at the verge of extinction include - yew trees, the bark of which forms the basis for one of the world's most widely used cancer drugs, paclitaxel.
Hoodia, which originally comes from Namibia and is attracting interest from drug firms looking into develop weight loss drugs, is on the verge of extinction, the report said.
And half of the world's species of magnolias are also under threat.
The plant contains the chemical honokiol, which has been used in traditional Chinese medicine to treat cancers and slow down the onset of heart disease.
The report also said autumn crocus, which is a natural treatment for gout and has been linked to helping fight leukaemia, is at risk of over-harvest as it is popular with the horticultural trade because of its stunning petals.
"The loss of the world's medicinal plants may not always be at the forefront of the public consciousness," BBC quoted report author Belinda Hawkins, as saying.
"However, it is not an overstatement to say that if the precipitous decline of these species is not halted, it could destabilise the future of global healthcare," Hawkins added.
Richard Ley, of the Association of the British Pharmaceutical Industry, added: "Nature has provided us with many of our medicines. Scientists are always interested in what they can provide and so it is worry that such plants maybe at risk."