Baltic stonewort (Chara baltica)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



Like all stoneworts, the Baltic stonewort does not have true leaves or roots but has leaf-like branchlets in whorls around the stem and a mass of fine rhizoids that anchor the plant in sediment. Chara baltica is light bright olive green or dark to bright green in colour and has little calcium encrustation. It grows up to 90 cm in height and has small solitary acute spines scattered along the stem. The gaps between each whorl of branchlets (internodes) are 1-3 times as long as the branchlets themselves. Where present, male reproductive bodies are larger than 0.5 mm in diameter. It is anchored in mud or silt my translucent rhizoids and can give out an unpleasant odour.

Recorded distribution in Britain and Ireland

Found at three sites in the Western Isles, Scotland and also from Shetland, the Norfolk Broads, Anglesey, Cornwall, and Devon, although previously recorded from 16 sites around Britain. There is an unconfirmed record from county Silgo, Ireland.

Global distribution

Northern coastal Europe including France and Holland, with most frequent records from reduced salinity areas of the Baltic. Also known from Greenland and Bolivia.


Usually inhabits clear brackish water up to up to 7 m deep, though is more common above 2.5 m Chara baltica grows in calcareous sandy and marly substrata in lagoons, lakes, pools, ditches, quarry pools, streams, sand dune pools and pits by the coast. It is often found at the gradually shelving edges of lakes or muddy substrata in lakes and lagoons. This species inhabits mostly brackish waters, in the UK habitats salinities tend to be very low.

Depth range


Identifying features

  • Up to 90 cm in length.
  • Solitary spines on the stem.
  • Internode length gradually decreases throughout the stem.
  • Bracts in each whorl are equal or of different lengths.
  • Thallus may have a strong unpleasant odour.

Additional information

Only female plants occur in northern Europe and the species reproduces parthenogenetically (Bryant & Stewart, 2002). Stoneworts get their name from calcium deposits on their stems that give them a stony or gritty texture. The identification of Chara baltica is difficult and samples should be sent to the National Stoneworts Recorder for identification.


  1. Bryant, J.A & Stewart, N.F., 2002. Order Charales. In: John, D.M., Whitton, B.A. & Brook, A.J. (Eds.) The Freshwater Algal Flora of the British Isles. An identification guide to freshwater and terrestrial algae. Cambridge: Cambridge University Press.

  2. Lambert, S., 2007. The Environmental Range and Tolerance Limits of British Stoneworts (Charophytes). PhD,  University of East Anglia, Norwich.

  3. Lambert, S., 2009b. Stoneworts: their habitats, ecological requirement and conservation. Using science to create a better place: Integrated catchment science programme, Environment Agency, Bristol, pp. 23. Available from

  4. Moore, J.A., 1986. Charophytes of Great Britian and Ireland. London: Botanical Society of the British Isles.

  5. Stewart, N.F. & Church, J.M., 1992. Red data books of Britain and Ireland: stoneworts. Peterborough: The Joint Nature Conservation Committee

  6. Stewart, N.F., 2004. Important Stonewort Areas. An assessment of the best areas for stoneworts in the United Kingdom. Plantlife International, Salisbury, UK.


  1. Botanical Society of Britain & Ireland, 2018. Other BSBI Scottish data up to 2012. Occurrence dataset: accessed via on 2018-09-25.

  2. National Trust, 2017. National Trust Species Records. Occurrence dataset: accessed via on 2018-10-01.

  3. NBN (National Biodiversity Network) Atlas. Available from:

  4. Norfolk Biodiversity Information Service, 2017. NBIS Records to December 2016. Occurrence dataset: accessed via on 2018-10-01.

  5. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-07-22

  6. Royal Botanic Garden Edinburgh, 2018. Royal Botanic Garden Edinburgh Herbarium (E). Occurrence dataset: accessed via on 2018-10-02.


This review can be cited as:

Barnes, M.K.S. 2008. Chara baltica Baltic stonewort. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 22-07-2024]. Available from:

Last Updated: 27/03/2008