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.
Range & Status
Forms small (to 3cm) finely branched tufts confined to the intertidal zone where it is
epilithic on rock, epizoic on mussels and other invertebrates and epiphytic on Corallina spp. of red seaweed. Often misidentified, many records being the much more common and widespread species P. stricta . Restricted to southern and western areas on wave-exposed shores.
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.