This book, the twelfth reprint of a book originally published in 1973, is a concise reference work containing information on various legal (in USA) psychotropic materials including plant materials, herbal formulations and chemicals synthesized or extracted from natural materials. For each entry, listed in alphabetical order of vernacular name, there is a description of the material and information on the method of preparation, dosage and use, analysis of active constituents, effects, contraindications and commercial supplier(s). Plants are also listed with Latin and family names.