Since the publication of Lewin's "Phantastica," interest in the hallucinogens has gradually grown, until now their use, misuse and abuse make daily headlines in the technical, pseudo-technical and popular literature. It would seem, then, that an appropriate time has come to consolidate what we know of these curious plants and to try to evaluate the extent of what still remains for discovery in the botany of the hallucinogens. It is, rather, the searching out of narcotics still in use by primitive societies but as yet unknown or only poorly known to the scientific world that I wish to consider. My thinking in this essay will try to follow the guide-lines set up by Harshberger, one of the fathers of American economic botany who first used the term "ethnobotany," when he wrote (15): "It is of importance ... to seek out these primitive races and ascertain the plants which they have found available in their economic life, in order that perchance the valuable properties they have utilized in their wild life may fill some vacant niche in our own." Some of these aboriginal plant uses have been recorded in the literature, but the botanical work basic to their identification has languished. Others have never been reported in the literature, or else they are known from very vague reports and await what is virtual discovery through anthropological and ethnobotanical field work.