Cornish Biodiversity Network  -  Supporting Wildlife Recording

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Cornish Red Data (2009)

The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.

Riccia crystallina - Blue Crystalwort

Range & Status

Known in S. Africa, C. and S. America, Caribbean, Australia and much of S. and C.

Europe, extending northwards to France and the former Russian Baltic. In Britain known mainly in the Isles of Scilly, but also from two sites in Cornwall and a single site in Scotland (Renfrewshire).

Regional Distribution

Widespread throughout the inhabited islands in Scilly (17 tetrads). Recent records from coastal car parks in W. Cornwall (Marazion, SW53A, 2005) and E. Cornwall (Porthluney Cove, SW94Q, 2002) show that it is now colonising the mainland.

Habitat & Ecology

Locally abundant in Scilly in bulb and potato fields and sometimes on paths, growing

on sandy soil with other bryophyte colonists, often in shaded places. The species is

monoicous and produces abundant spores that mature from January to June.


Not threatened in Scilly, where it is widespread and plentiful.



Click here to see Aphotoflora images by David Fenwick


I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.

The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.

Cornish Biodiversity Network. 2017.