The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
(syn. T. nematodes auct. eur. non (Gottsche ex Aust.) Howe, T. sejuncta auct. non (Angst.) S.W.Arnell). Mainly a tropical and subtropical species, occurring in tropical and southern Africa, in Macaronesia, and very locally along the Atlantic fringe of Europe from Portugal northwards to W. Ireland. Similar plants in the Americas from Peru northwards to New York are now regarded as a different species. Originally thought to be an introduction to the British Isles, but it is now regarded as a native species, at least in W. Ireland (Smith, 1990). The only British locality is in W. Cornwall.
One locality, at Trevellow Carn south-west of Penzance (SW42N).
Habitat & Ecology
A tiny, mat-forming, leafy liverwort. The Cornish site is on humic soil and steep granite rocks, where shaded by Rhododendron Rhododendron ponticum and Cherry Laurel Prunus laurocerasus . In Ireland it favours moist peaty banks, peat on rocks and rotting wood, usually in deeply shaded, humid sites under Rhododendron in woodlands and thickets, on or near the coast. It is a monoicous species that often produces sporophytes, maturing in May and June. Axillary bulbils are produced (Paton, 1999), which probably serve for vegetative reproduction.
The Cornish site is in private grounds. T. nematodes was present in considerable quantity there in 1996. Its persistence will probably depend on the maintenance of deeply shaded habitat under Rhododendron and Cherry Laurel, so that this is probably the only site in Cornwall at which these shrubs should be encouraged!
Listed as Vulnerable in the UK Red-list (Church et al ., 2001); added to the UK BAP in 2007.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.