Guidelines for consistent characterisation and documentation of plant source materials for studies in phytochemistry and phytopharmacology.

Plants are still by far the most important source of natural products. For higher plants as source materials identification and documentation are less challenging than for many other groups of organisms such as microorganisms or marine invertebrates. Nonetheless, many studies in natural products chemistry and phytopharmacology involving higher plants are flawed because the plant material is erroneously assigned, inaccurately documented, untraceable, or not named in accordance with the rules of nomenclature. Recently, the importance of the proper usage of plant nomenclature has been highlighted in a dedicated series of articles in the Journal of Ethnopharmacology and the importance of taxonomic and geographic information in a viewpoint in Natural Products Reports. Here, the importance of three related points is being emphasized: a) the traceability of the identification of plant source materials, b) easy access to vouchers and digital vouchers of the studied plants, and c) standards for accurate geographic data about the collection sites of these plants.