The habitats where water lobelia~(Lobelia dortmanna) grows:

Fast flowing river and stream
Lowland fen
Marginal and inundation
Nutrient rich eutrophic lake
Peat stained (dystrophic) water
Pond ditch and canal
Sluggish river and stream
Turlough and fluctuation mere
Upland lake loch and tarn
Upland spring flush