This horsetail is very common in ponds, lakes, ditches, fens and other aquatic situations. It stands about one or two feet tall (sometimes more) and grows vertically up from a horizontal rhizome (creeping stem) which is buried in the mud below the water. It can be either completely unbranched, or have regular whorls of short branches. There is a large central hollow down the centre of the shoots. Blackish cones are produced at the tips of the shoots.
All names: Equisetum fluviatile L.; Equisetum limosum L.