Identification notes
The first time you see this moss you may think it is a species of Mnium rather than an Atrichum. This is understandable as the parallel lines of lamellae that are normally visible on the upper surface of the nerve in Atrichum species are obscure in this one.
It’s a very attractive little moss and certainly looks very much at home by fast-flowing hill streams and lakes in the uplands. However, it’s an introduction from North America, first seen in 1848 in Lancashire. Since then it has spread far and wide by spread by fragments or rhizoidal gemmae and is now quite common in some districts. Only male plants are known from Britain and Ireland, all of which are thought to be clones of that first Rochdale plant.
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