VALERIANA OFFICINALIS L. IN HOLLAND

Summary

Valeriana officinalis L. is an extremely variable species, treated taxonomi–cally very different in different countries. A short review of the taxonomical and cytological literature is given.

The authors investigated the species in the Netherlands by cultivating plants collected throughout the country (Fig. 1) and by examining the specimens of the Rijksherbarium of Leiden (Fig. 2). In our study macromorphological, micromorphological and numerical characters were used. With 55 plants the number of chromosomes was counted. The characters of the Dutch plants were compared with those of cultivated plants originating from Sweden, Poland, Germany and Luxembourg.

All Dutch plants proved to be octoploid (2n = 56). The other characters investigated were very variable.

As a result of our investigation we believe that Valeriana officinalis L. cannot be split in a number of smaller species if the whole distribution range is considered. There are no sharp discontinuities between the different morphological forms. The best manner to account for the great geographical and ecological differentiation of the species seems to be to accept a number of subspecies.

For the pharmacognosist the species is very difficult to handle because there is no doubt that the chemical characters have participated in differentiation. The usual manner of defining the drug by describing the species from which it derives is unsatisfactory. A chemical or pharmacological definition and standardisation is impossible likewise.

It is suggested that this problem should be solved in collaboration with centres of cultivation of medicinal plants. To assure a constant quality of the drug it seems necessary to declare official a definite cultural variety or a cultivated clone.

At all events it may be anticipated that our knowledge of this old vegetable drug (chemistry, pharmacology) would extend rapidly if every research worker investigating Valerianae Radix was aware of the great geographical variability of the species procuring the drug and would pay therefore sufficient attention to the exact botanical identification of the material used.