INTRASPECIFIC VARIABILITY OF SOUTHERN SWEET-GRASS (HIEROCHLOË AUSTRALIS/SCHRAD./ ROEM. & SCHULT.) WILD GROWING IN POLAND

Southern sweet-grass is a tuft-grass naturally occurring in Poland. The leaves of this plant are coumarin raw material used in medicine as well as in food and tobacco industry. The content of coumarin in the leaves is the most important quality discriminant of the raw material. This species being under partial legal protection is seriously endangered because of excessive, uncontrolled collecting. Taking into consideration this danger the trials of its cultivation were undertaken in our Department. The aim of the study was to investigate the intraspecific variability of southern sweet-grass wild growing in the eastern area of Poland. The differences concerning the coumarin and related compounds between six geographically distant populations and between 42 individuals (belonging to one population) were investi-gated. Both the populations and the individuals distinctly differed in the content of all detected coumarin compounds: coumarin, 3,4-dihydrocoumarin and o-coumaric acid. The highest differences between individuals were found in the content of coumarin (from 87.07 to 1082.43 mg×100 g^-1 of dried raw material). There were also visible differences between individuals in the intensity of powdery bloom on the leaves. The plants with leaves coated with thick white bloom were characterized by significantly higher content of coumarin in comparison with plants without visible bloom. It may indicate that this compound is partly secreted from the leaves and accumulated in the powdery bloom.