Rainbow wrack (Cystoseira tamariscifolia)

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

Summary

Description

Cystoseira tamariscifolia is a bushy seaweed, up to 60 cm in length but usually 30-45 cm. It has a cylindrical frond and branches irregularly. The reproductive bodies on the end of branches are long, oval and spiny. Small air bladders are usually found below the reproductive bodies. Cystoseira tamariscifolia is olive green in colour, almost black when dry. When the plant is seen underwater it has a blue-green iridescence.

Recorded distribution in Britain and Ireland

A southern species recorded in southwest Britain, recorded around the coast of Ireland predominantly in the west and although recorded from the Hebrides, rare in the north.

Global distribution

Found in the north east Atlantic, Mediterranean and southeast Atlantic.

Habitat

Found in rockpools and on the lower shore. Grows on both rocky shores and gravelly flats.

Depth range

-

Identifying features

  • Blue-green iridescence underwater.
  • Almost black when dry.
  • Rough texture, bushy appearance.

Additional information

May be confused with other species of Cystoseira but can be distinguished by the characteristic blue-green iridescence when the plant is underwater.

Listed by

- none -

Further information sources

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Bibliography

  1. Fish, J.D. & Fish, S., 1996. A student's guide to the seashore. Cambridge: Cambridge University Press.

  2. Gibson, R., Hextall, B. & Rogers, A., 2001. Photographic guide to the sea and seashore life of Britain and north-west Europe. Oxford: Oxford University Press.

  3. Guiry, M.D. & Nic Dhonncha, E., 2002. AlgaeBase. World Wide Web electronic publication http://www.algaebase.org,

  4. Hardy, F.G. & Guiry, M.D., 2003. A check-list and atlas of the seaweeds of Britain and Ireland. London: British Phycological Society

  5. Hayward, P., Nelson-Smith, T. & Shields, C. 1996. Collins pocket guide. Sea shore of Britain and northern Europe. London: HarperCollins.

  6. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]

  7. JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid

  8. Stewart, W.D.P., 1962. Occurrence of Cystoseira tamariscifolia (Huds.) Papenf. On the West Coast of Scotland. Nature, 195, 402-403.

Datasets

  1. Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.

  2. Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01

  3. National Trust, 2017. National Trust Species Records. Occurrence dataset: https://doi.org/10.15468/opc6g1 accessed via GBIF.org on 2018-10-01.

  4. Nature Locator, 2017. Sealife Tracker. Occurrence dataset: https://doi.org/10.15468/qgk3pg accessed via GBIF.org on 2018-10-01.

  5. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  6. OBIS (Ocean Biodiversity Information System),  2025. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2025-05-21

  7. Royal Botanic Garden Edinburgh, 2018. Royal Botanic Garden Edinburgh Herbarium (E). Occurrence dataset: https://doi.org/10.15468/ypoair accessed via GBIF.org on 2018-10-02.

Citation

This review can be cited as:

Ager, O.E.D. 2008. Cystoseira tamariscifolia Rainbow wrack. 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 21-05-2025]. Available from: https://www.marlin.ac.uk/species/detail/1914

Last Updated: 29/05/2008