Taxonomists describe and classify plant materials and the scope for investigation is very wide. Chemical data, as one of the characteristics of a plant, may aid classification. The author then discusses a wide range of plants with typical specific or unusual chemical compounds which they contain and reviews some recent studies. For example, the various essential oils found in wood species have been studied, with differences sometimes found between winter and summer produced oils. Although the author does not discuss the application to archaeology/ art history it is clear that taxonomy provides a useful body of data on chemicals to be found in natural products. Ancient materials can perhaps be identifled by the finding of characteristic chemical compounds which distinguish the original parent material, e.g. resins, oils, pigments, etc. -- AATA