text: Distribution and habitat The species is native to marshes, fens, ditches and wet woodland in temperate regions of the Northern Hemisphere. It can be found in much of the northeastern United States.
  Ecology
  The marsh-marigold grows in places with oxygen-rich water near the surface of the soil. It likes richer soils, but dislikes application of fertilizer and avoids high concentrations of phosphate and ammonium, and is also shy of brackish water. It is often associated with seepage that is rich in iron, because iron ions react with phosphate, thus making it unavailable for plants. The resulting insoluble mineral appears as "rusty" flocs on the water soil and the surface of the stems of marsh plants. Around the edge of lakes and rivers it grows between reeds, and it can be found in black alder coppices and other regularly flooded and always moist forests. When it is present it often visually dominates when it is in bloom. It also used to be common on wet meadows, but due to agricultural rationalization it is now limited to ditches.
  It is a component of purple moor grass and rush pastures – a type of Biodiversity Action Plan habitat in the UK. It occurs on poorly drained neutral and acidic soils of the lowlands and upland fringe.