Variability of southern sweet-grass (Hierochloë australis /Schrad./ Roem. & Schult.) wild growing populations occurring in eastern Poland

Southern sweet-grass is a perennial grass distributed through north-eastern Europe. In Poland, this rare, partially protected plant grows wild in well-lit coniferous or mixed forests. Its leaves, rich in coumarin compounds, are used for aromatization of alcohols. Taking into account high demand on this raw material and decrease in the number of southern sweet-grass populations it is recommended to introduce the plant into cultivation systems. In this study 12 populations of southern sweet-grass were selected and assessed in terms of their cultivation usefulness. The presence of associated plant species growing on its natural sites was investigated as well as light irradiance on those stands. The species was found in 3 types of forest communities. Air dry mass of leaves per plant varied in analyzed populations from 1.73 to 11.07 g. They were significantly diversified in the total content of coumarins (0.36–0.96%), flavonoids (0.09–0.26%) and polyphenolic acids (0.13–0.29%). The diversity concerning the content of coumarin, a quality indicator of leaves, was even higher. The content of this compound varied from 52.03 to 275.74 mg/100 g d. m. Among the analyzed populations, the most interesting seem to be population No. 12 (Jedwabno) and population No. 10 (Ruciane) characterized with relatively high mass of leaves and the highest content of the identified active compounds, including coumarin.