Liverwort (Cephaloziella massalongi)

KingdomPlantae
PhylumHepatophyta
ClassHepatopsida
OrderJungermanniales
FamilyCephaloziellaceae
GenusCephaloziella (1)
SizeLength: 6-8 mm (2)

Classified as Vulnerable in Great Britain (3).

This liverwort has a leafy appearance with yellowish-green, dark red-brown or black shoots that either lie along the ground or are raised upwards (3). The shoots support leaves that have toothed edges (3). Although this species is minute, it can often develop into fairly sizable patches (3). It is very similar in appearance to the related species Cephaloziella nicholsonii, and only detailed examination can distinguish the two (3). Cephaloziella nicholsonii is often larger, up to 15 mm long, is more fertile and produces asymmetrical gemmae, whereas Cephaloziella massalongi produces symmetrical gemmae (2).

In Great Britain this liverwort is known only from the south-west of England and north Wales, and is locally abundant at a number of sites in Cornwall and Devon (3). Elsewhere it has a wide distribution, occurring in north-western Europe, where it is classified as rare, and in the southern Appalachian Mountains in the USA (3).

Typically grows around copper mines or other copper-enriched habitats in damp acidic soil, on walls, rocks, and mine-spoil (3).

Liverworts, hornworts and mosses form a group of plants called bryophytes (3). Bryophytes lack many of the more complex structures of the higher plants, such as a vascular system, and flowers. They do not have roots, instead they have structures called 'rhizoids' which absorb water and anchor the plant to the substrate. In liverworts these rhizoids each consist of a single elongated cell (4). Bryophytes have an interesting life cycle, which consists of two main stages, called the gametophyte and sporophyte generations, the gametophyte generation is dominant. In the UK, Cephaloziella massalongi reproduces by producing special groups of cells called 'gemmae' (3) which develop into new plants (4). This species often occurs with C. nicholsonii, but it appears to be less resistant to dry conditions than the latter (3).

This liverwort has been lost from a number of sites in Anglesey and Gwynedd in Wales (3), it is thought that over-tidying of derelict land and land reclamation schemes may pose threats to the species (3).

Most of the sites that support this species are unprotected; just two occur within designated Sites of Special Scientific Interest, one in Cornwall, and the other in Wales (3). Site protection has been proposed for the strongest populations (3).

Information authenticated by Royal Botanic Gardens, Kew:
http://www.rbgkew.org.uk/

  1. National Biodiversity Network Species Dictionary (May 2002) http://www.nhm.ac.uk/nbn/
  2. Paton, J. A. (1999) The liverwort flora of British Isles. Harley Books, Colchester.
  3. Church, J. M., Hodgetts, N. G., Preston, C. D. and Stewart, N. F. (2001) British Red Data Books: mosses and liverworts. Joint Nature Conservation Committee, Peterborough.
  4. Mosses and Liverworts in Wales (May 2002): http://home.clara.net/adhale/bryos/