The Effects of Chemical Preservations on Plant Collections to Be Used in Chemotaxonomic Surveys

Summary The absence of flavonoids in otherwise perfectly preserved tropical plant specimens suggest that chemical solutions used to preserve these specimens in the field are responsible for the removal (i.e. pre‐extraction) of flavonoids during pressing and storage in the field. Accordingly, seventeen temperate plant taxa representing two fem and nine angiosperm families were subjected to collecting procedures and preservative solutions typically used in tropical field work. These solutions, especially those containing formaldehyde, effectively “pre‐extracted” flavonoids and other phenolics from plants placed in presses and stored in plastic bags, and the newspaper blotter in which the chemically treated specimen had been stored could also be extracted and upon two‐dimensional paper chromatography show a partial flavonoid “profile” of spots corresponding to that observed in the “donor” species. Direct extraction of fresh or dried material in flasks with any of the common preservatives used confirms that all of these solutions are highly effective in extracting flavonoids. It is recommended that chemical preservatives not be employed indiscriminately on plant material to be used later in chemotaxonomic surveys.