Status in Britain: Red Data Book
Other: European RDB; Biodiversity Key Species

A small thallose liverwort with a rosette-like habit. It is a colonist of recently exposed mud at the edge of ponds lakes and reservoirs, as well as rivers. It is a Red Data Book species in the UK and known from only a few sites in Wales. Where it does occur it can be in some quantity for relatively short periods of time (perhaps weeks), and then disappear again.

(For those not familiar with UK coinage, the five-pence piece is about 18mm in diameter).