The principal tool for monitoring or restricting trade of species threatened by over-exploitation is the Convention on International Trade of Endangered Species of Wild Fauna and Flora, or CITES, which entered into force in 1975. The 158 national governments who currently have signed CITES are obliged to monitor and control international trade in the plants and animals listed in its two main Appendices.
Appendix I prohibits trade in wild specimens, except for reasons such as scientific research. Appendix II requires parties to issue export permits that confirm non-detrimental harvest of listed species, and requires importing countries who are Parties to CITES to check and monitor permits on incoming material. It is important to note that for Appendix II species it is solely the country of export that decides whether to issue a permit or not.
Having become parties to CITES, national governments are required to establish or designate scientific authorities to conduct non-detriment studies for listed species, and management authorities to issue permits and certificates.
Species can be added, removed, or shifted between Appendices through proposals passed at biennial meetings of the signatories, or Conferences of the Parties. 17 species have been added to CITES Appendices because of their exploitation as medicinal plants, the majority of them in the 1990's (Table 9).
For medicinal plant conservation, CITES accomplishes a number of tasks very well, including: (i) monitoring trade at the species level; (ii) focusing attention on high use, high priority species with global value; and (iii) calling international attention to threatened medicinal plant species.
As a conservation tool, CITES also has a number of limitations: (i) Many countries are reluctant to support inclusion of important commercial species on CITES, even when there is justification for restricting or monitoring trade, for fear of losing needed international exchange. (ii) Internal trade is not monitored. (iii) A substantial amount of international trade is not monitored because exported material, such as dried bark and extracts, can be difficult to tie to particular species. (iv) CITES focuses on species that are already threatened, rather than preventing the threat.