Multi-fruited river moss (Cryphaea lamyana)

GenusCryphaea (6)
SizeLeaf width (at mid-leaf): 8-12 µm
Spore size: 18 µm

Classified as Vulnerable in Great Britain and fully protected under Schedule 8 of the Wildlife and Countryside Act 1981(1).

Multi-fruited river moss has a creeping stem from which short branches arise (1). It is not as highly branched as the similar species C. heteromalla, and has blunter and shorter leaf tips (1). Mosses are broadly divided into two main types, called 'acrocarpous' and 'pleurocarpous' mosses (4). This species is a 'pleurocarp' (1); the female sex organs (archegonia) are produced on short side branches, and not at the tips of stems and branches. These species tend to grow as spreading carpets rather than as erect tufts (5).

In Britain, multi-fruited river moss occurs only in south-west England and south-west Wales (2). Good populations are known in East Cornwall and South Devon along the River Tamar, and in North and South Devon on the Bovey (1), but the main stronghold occurs along the Afon Teifi in Cardiganshire (2). Elsewhere this moss occurs on the Atlantic coast of continental Europe reaching south to Portugal, and in the western Mediterranean (1).

Occurs in the flood zone of rivers, growing on exposed roots, tree trunks, overhanging branches and rock faces (1), and occasionally on stone bridges (2). It tends to avoid very shaded areas, possibly as a result of increased competition from other mosses (3).

Mosses, hornworts and liverworts form a group of simple plants called bryophytes (1). 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. All bryophytes have an interesting life cycle consisting of two main parts, called the gametophyte and sporophyte generations (4). Plants that are in the gametophyte stage can reproduce sexually. Male organs (antheridia) produce male sex cells or gametes called antherozoids, which actually move to the female sex organs (archegonia) (4) through water droplets (7). Fertilisation occurs and a plant develops called a 'sporophyte', which remains attached to the plant. The sporophyte releases spores from within a capsule; the spores disperse and develop into a new gametophyte stage plant (4).

Although there is no evidence that this moss has declined in Great Britain, it is vulnerable because it depends on a small number of trees at each site; these trees must be protected (1). Possible threats include river engineering works such as bank straightening, and removal of boulders and trees from the banks, as well as pollution of the water, shading from trees and dredging activities in which the silt is dumped upon or dragged across the habitat of this moss (2).

Multi-fruited river moss is a UK Biodiversity Action Plan Priority Species, and is afforded special protection under Schedule 8 of the Wildlife and Countryside Act 1981 (2). The Species Action Plan aims to maintain the current range of this moss and extend it where possible, and establish ex-situ stocks of the species by 2005 (2). Plantlife, the Lead Partner for this species has included it on its Back From The Brink programme.

For more on this species see:

The UK Biodiversity Action Plan Species Action Plan, available on-line at:

Plantlife Species Dossier:

For more on Plantlife's Back from the Brink programme see:

Information authenticated by Plantlife, the wild plant conservation charity:

  1. National Biodiversity Network Species Dictionary (September, 2002)
  2. 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.
  3. Mosses and Liverworts in Wales (September, 2002)
  4. Allaby, M. (1998) Oxford Dictionary of Plant Sciences. Oxford University Press, Oxford.
  5. UK BAP (September, 2002)
  6. The Environment Agency: Focus on Biodiversity. (September, 2000)
  7. Egerton, H. and Jones, F. (1998) Nature Encyclopedia. Dorling Kindersley, London.