Beaked beardless moss  (Weissia rostellata)

Eutrophication: nutrient enrichment of aquatic or terrestrial ecosystems.
Gametophyte: a life cycle stage in plants, which has one set of chromosomes (threads of DNA protein) in the cell nucleus (a condition known as ‘haploid’), which arises from a spore (which is also haploid). Sex cells (gametes) are produced during the gametophyte stage. This is the dominant life-cycle stage in liverworts and mosses.
Rhizoids: thread-like structures that help to anchor the plant to the substrate, and absorb minerals and water. In liverworts they consist of a single cell, in mosses they are multi-cellular.
Spore: microscopic particles involved in both dispersal and reproduction. They comprise a single or group of unspecialised cells and do not contain an embryo, as do seeds.
Sporophyte: the stage of a plant life cycle that produces spores (microscopic particles used in dispersal and reproduction). This stage is diploid (in the cell nucleus there are two sets of chromosomes - threads of DNA protein) and is dominant in ‘higher’ plants such as flowering plants.
Vascular system: in plants, the system that allows water and nutrients to move around.

1. Systema Naturae 2000 / Classification- Parker (1982) - (July 2002):
   http://members.ams.chello.nl/jwabr/SN2000/1982%20Parker/Classification/1.htm
   
2. The Environment Agency (2000) Focus on Biodiversity. The Environment Agency, Bristol.
   
3. UK BAP Species Action Plan (July 2002):
   http://www.ukbap.org.uk
   
4. Holyoak, D. T. (2002) Violet crystalwort (Riccia huebeneriana) and beaked beardless-moss (Weissia rostellata): Report to Plantlife on work carried out in southern England during 2001. Report number 198, ISBN 1 87261369 1. Plantlife, London.
   
5. Mosses and Liverworts in Wales. (July 2002):
   http://home.clara.net/adhale/bryos/