Taxonomy

Lycopodiella inundata (L.) Holub. is also known as Lycopodium inundatum L. Its common name is Marsh Clubmoss.

2n = 156.

Distribution

The main populations in Britain are found in the south of England, in the New Forest and on heaths in Hampshire and Surrey. It also occurs in Scotland, in bogs and on the margins of lakes. Between these two centres of population there are a few isolated localities such as North Wales and Cumbria. It was once more widespread, but it disappeared from many sites in England prior to 1930 as a result of drainage and agricultural intensification.

Its highest recorded altitude is 390m at Llyn Cwmffynon (v.c. 49) by Trevor Dines in 1999 (Pearman 2004).

It has a curious distribution globally, in scattered locations throughout much of Europe, and is on both the east and west coasts of North America (mapped by GBIF as Lycopodium inundatum), where it is rare.

Ecology

It is a short-lived perennial of bare peat in mires and heaths.

Rasmussen & Lawesson (2002) studied its contrasting ecology in England and Scotland and concluded that the closest vegetation type for it in England was M16 Erica tetralix-Sphagnum compactum heath, whereas in scotland it occurred in M15 Trichophorum cespitosum-Erica tetralix heath and M29 Hypericum elodes-Potamogeton polygonifolius soakways.

In its lowland English sites it is often maintained by drastic management activities to produce bare soil, whereas on the edge of peaty lochs in Scotland the harsh conditions and fluctuating water levels produce this habitat naturally.

Status

It is considered native to Britain and Ireland. The first British record was by Christopher Merrett (1666) at Putney Heath in Surrey.

It is Nationally Scarce, currently listed as Endangered in the JNCC’s Red List. It is also a Priority BAP plant.