Scapania undulata Water Earwort

A dioicous leafy liverwort which grows in very wet places on rock, sand and gravel by streams, in ditches, in woodland and other places. It is the most common species of Scapania in Britain and although it is quite variable, the dark green, sometimes reddish, mats which are often extensive on rocks irrigated by flowing water can usually be identified without much problem. The closely appressed, rounded lobes are quite distinctive. It is widespread and abundant throughout most of western and northern Britain, but absent from much of the south and east. It is found throughout Wales and it is common ouside Gower in West Glamorgan. Sporophytes are common.