Fissidens viridulus Green Pocket-moss

A minute, autoicous or dioicous Pocket-moss with bordered leaves, which occurs on mildly calcareous or slightly acidic banks in woodland or beside streams. It is a fairly common species in southern Britain and south Wales and it is widespread in West Glamorgan. It is usually necessary to look at the leaf under the microscope to confirm that the the border ends before the tip and is not confluent with the nerve (see photos). Another useful feature is that the leaf edge is concave on one side near the apex making it look quite asymmetric, but not all leaves show this character very strongly. Confusion with Fissidens crispus is possible (see description of that species). Sporophyte capsules are common from winter through to spring.