A prostrate perennial herb of wet, bare, peaty or sandy margins of lakes, pools, flushes and trackways. It can rapidly colonise substrates kept open by winter inundation, cattle poaching or peat cutting. 0-390 m (Llyn Cwmffynnon, Caerns.).
Many sites for L. inundata were lost before 1930, and losses have continued due to drainage, a lack of grazing and other disturbance, and conversion to scrub, especially in England. However, it is easily overlooked and new sites have been found outside England since the 1962 Atlas.
European Boreo-temperate element; also in E. Asia and N. America.
Count of 10km squares in Great Britain: 233
Count of 10km squares in Ireland: 18
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: -0.65
External Species Accounts
Scarce Atlas Account
Lycopodiella inundata (L.) Holub
L. inundata is a short-lived perennial of bare peaty, occasionally silty or sandy, areas on mires, heaths, lake margins and sand and clay pits. These areas are normally submerged under water in winter and spring. It is most commonly associated with Sphagnum auriculatum and Rhynchospora alba on the edge of valley mires of the New Forest. Rhynchospora fusca, Drosera intermedia and Hammarbya paludosa are sometimes found growing with L. inundata. Human activities which provide areas of bare, seasonally flooded, well humified, acidic peat, such as tracks and old peat cuttings, favour this species. It is most common where high grazing pressure results in the poaching of wet heath and mire surfaces. Where bare ground is present it may become locally abundant. It is virtually restricted to lowland sites, but reaches 305 metres at Loch Ba.
Branches remain evergreen for two years, after which the clone fragments by disintegration of the older sections of the branches. It spreads relatively slowly at 2 to 10 cm each year. Strobili produced in summer mature in the autumn. Spores may be dispersed by air or by water within intact sporangia when the plant becomes submerged. The gametophyte stage is superficial and green and takes a few years to reach maturity. Other members of its genus reproduce more readily by sexual means than species of Lycopodium.
The drainage of bogs and successional changes in its habitat have resulted in this species disappearing from many sites in lowland England. In southern England it has increasingly become restricted to areas kept open by human disturbance. Until recently it has remained somewhat overlooked around the margins of Scottish lochs.
L. inundata is found throughout most of Europe, except the Mediterranean region, but it has declined markedly in recent times. Its European distribution is mapped by Jalas & Suominen (1972). It is also found on the eastern and western sides of North America.
A. D. Headley
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.
Atlas text references
Atlas (1b) Dorset's disappearing heathland flora,
, London, (1996)
The Irish Red Data Book. 1. Vascular Plants,
, Dublin, (1988)
Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols,
, Königstein, (1986)
Jalas & Suominen (1972) Ferns and their allies,
, The Island of Mull: a survey of its flora and environment, London, p.12.1-12.7, (1978)
Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols,
, Jena, (1965)
The ferns of Britain and Ireland, edn 2,
, Cambridge, (1997)
Scarce plants in Britain,
, Peterborough, (1994)