Bryum marratii Baltic Bryum

A distinctive, autoicous Bryum with somewhat obtuse, evenly-spaced leaves and almost spherical sporophyte capsules. It is halophytic and tends to grow in small populations on mud or damp sand near the sea, e.g. along the upper edges of salt marshes or where there is weakly saline seepage. It can be confused with Bryum calophyllum and, according to the Atlas of British and Irish Bryophytes, records from dune slacks are mainly due to misidentification of non-fertile material of that species. Bryum calophyllum has shortly ovoid capsules (not spherical) which are usually abundant in autumn, but non-fertile material is very difficult to identify with certainty. Bryum marratii is very rare in Britain and sparsely distributed along the coast. The only records in West Glamorgan are from Whiteford in Gower where it was first discovered by Sam Bosanquet in 2012.