The habitats where marsh violet~(Viola palustris) grows:

Alpine and subalpine calcareous grassland
Blanket bog
Coastal floodplain grazing marsh
High montane heath and snow bed
Limestone pavement
Lowland dry acid grassland
Lowland fen
Nutrient rich eutrophic lake
Purple moor grass and rush pasture
Raised bog
Rocky slope
Scree
Turlough and fluctuation mere
Upland acid grassland
Upland birch wood
Upland calcareous grassland
Upland dry heath
Upland rush pasture
Upland spring flush
Upland wet heath
Valley mire
Wet woodland