British distribution: Formerly widespread but now extinct over large areas; surviving on wet heaths in the south of England and in scattered localities in Scotland, very rare elsewhere. 'Nationally Scarce.'
Lycopodiella inundata is a species of wet, open, usually peaty ground, typically flooded in winter. Favoured sites are those where bare areas have been created by peat or turf cutting or where cattle have trodden. It is now primarily a species of wet heaths in the New Forest, Dorset and Surrey in the south of England, though it is also scattered in westerrn Scotland and with a few surviving sites elsewhere. It is the only British species of the genus.
150 years ago it was described as 'common' (Moore, 1855) but it has since undergone a drastic decline, primarily through habitat loss by drainage and loss of open microhabitats. The current British status of this species ('nationally scarce') is summarised by Headley (1994).
Like most other clubmosses, L. inundata shows an alternation of independent generations.
The 'dominant' generation is the sporophyte. The vegetative plant consists of trailing, rooting stems which are 'leafy', bearing narrow, simple microphylls. As in Lycopodium (q.v. for more background to this group), the sporangia are clustered into cone-like strobili, in which each sporangium is protected by a leaf-like sporophyll. However, in this species, the strobili are not so clearly defined, lacking a distinct stalk and with the sporophylls not distinct in appearance from the microphylls of the vegatative plant. The gametophyte is small, terrestrial and photosynthetic, taking a few seasons to mature.