Identification notes
This is a rare species of calcareous rocks and gritty soil beside streams in upland area. It is not clear why there are so few records in the presence of a large number of potentially suitable habitats, but it is dioicous with capsules not having been seen in Britain and it produces no specialised asexual propagules. It would be easy to pass this by as Bryum alpinum and it would be easy to overlook.
It is a relatively slender plant producing tufts of green shoots with red stems. The costa is red at the base and shortly excurrent, and the basal cells are reddish in older leaves. The border is poorly defined but the leaf margins are recurved at the base. It is mildly decurrent with short rectangular cells.
In the past it was confused with Bryum riparium until the differences were described in a classic paper by Harold Whitehouse in 1963.