purple loosestrife flowers, reed and trees on the side of a peat lake - lythrum salicaria

belgium blooming bog border botanical botany brown cultivar decorative diarrhea dysentry embankment flanders flemish flora floral flower flowering flowers focus garden herb hike hiking invasive kalkense lake loosestrife lythraceae lythrum many marsh medicinal medicine meersen natural nature ornamental peat plant pond pool purple reed reserve salicaria selective side tourism tourist trees water waterplant waterside wild wildflower wildflowers