Regional and habitat differences in 7-methyljuglone content of Finnish Drosera rotundifolia.

The concentration of 7-methyljuglone was studied in the round-leaved sundew Drosera rotundifolia L. collected from different regions in Northern Finland. Samples for analysis were collected from peat bogs and sandpit habitats. The mean concentration of 7-methyljuglone varied from 1.0 to 2.3% of dry weight. Variation between years in the amount of 7-methyljuglone was significant in plants growing on sand, and in the northernmost region studied. Overall, the variation in the production of 7-methyljuglone among different populations of round-leaved sundew in Northern Finland was rather low. The variation between years in the production of 7-methyljuglone was more significant.