Technical Abstract: A major objective of the discovery effort of the herbicide industry is to find new molecular target sites. One strategy for discovery of new molecular targets is to determine those for naturally-occurring phytotoxins. The relatively few molecular targets of natural projects that are known are almost all different from those of commercial herbicides. We describe the novel sites of action and novel mechanisms of action of some of the compounds with which we have worked. These include AAL-toxin, artemisinin, australifungin, cornexistin, 1,8-cineole, cyperin, and hydantocidin. Each of these compounds appears to have a mechanism of action that is very different from that of any commercial herbicide.