Range & Status
Known only in E. and W. Cornwall, Portugal, Madeira and the Azores. This very small leafy liverwort was not recognised in Britain until Paton (1990) distinguished it from M. sprucei (Limpr.) Bernet.
Recorded during 2000-2008 at two sites in W. Cornwall (near Lower Bostraze in W. Penwith) and seven in E. Cornwall (in St Austell china-clay district). Other populations recorded since the 1960s have become extinct.
Habitat & Ecology
Known in Cornwall mainly from disused china-clay pits or disused areas in working pits. It grows as a colonist on unshaded or lightly shaded hard clay, less often on low granitic rocks, typically in rather bare places (>50% unvegetated) in which Nardia scalaris Gray is often common and the very similar Marsupella sprucei is usually also present. It is a paroicous species in which gametangia and sporophytes commonly occur, the capsules ripening in March and April. Despite its English name, the plant is typically blackish-purple in colour.
It disappeared from at least six Cornish sites between 1971 and 2005 due to shading from Common Gorse Ulex europaeus and Bramble Rubus fruticosus agg. The habitat was destroyed at another site. All of the extant populations are potentially at risk from shading by taller plants as vegetation succession proceeds, so deliberate management is needed to maintain suitable open conditions.
The two extant sites in W. Cornwall and three of the sites in E. Cornwall are protected as SSSI and SAC; these sites are being managed by Natural England to maintain suitable habitat conditions for M. profunda . Listed as Vulnerable on UK Red-list (Church et al ., 2001), and as Critically Endangered under the IUCN Red List; placed on Schedule 8 of the Wildlife and Countryside Act 1981, as amended; included in Natural England' s Species Recovery Programme. This species is listed on the UK BAP Priority Species list (2007).