Thelypteris palustris Marsh Fern

A medium-sized fern with a thin creeping rhizome which often forms large stands in fenland, marshy grasslands and wet woodland, especially where soils are permanently wet and not too acidic. Plants die-back in winter and re-emerge in late spring to produce pale-green, upright fronds of two types, non-fertile fronds and taller, fertile fronds. It is a lowland species in Britain, mainly concentrated in the fenland of East Anglia but with scattered sites throughout the rest of England, Wales and Ireland. Flora of Glamorgan (1994) descibes it as 'appatrently extinct' in Glamorgan but although it is uncommon in south Wales generally, there are some large populations still extant in Glamorgan, one in marshy grassland in Cefn Cribwr (Mid Glamorgan) and the others in swampy Alder-Willow carr near Jersey Marine and in Crymlyn Fen in West Glamorgan. It has probably declined in many parts of Britain as a result of drainage and land use change. A population that once grew in the Clyne Valley was destroyed when the habitat became a landfill site.

Native