There are four main type of boggy habitats, or wetlands. Least common in the UK is a swamp, where trees are the dominant plant species; if herbaceous plants dominate, as is more usual, the site is a marsh. Both these lack peat-forming plants, unlike the other two wetland types, collectively termed a mire - a bog, which contains acidic water, or a fen, which contains neutral or basic water. Saltmarsh is a related coastal habitat.
