Llanelli Naturalists Newsletter - Summer 1997 - No 62
R Nigel Stringer & R H Davies

Well of course, it does help if one knows what it is before one starts looking for it.  To give everybody a clue - it doesn't move, doesn't make a noise, dries up periodically (no - not a Nats member in an AGM being asked to give a future walk or talk!) but it is very pretty.  Yes - got it in one - it's a heterotrophic thallophytic cryptogram! or commonly known as a fungus.

As everybody knows fungi are an extremely difficult group to identify to species level but P. caeruleum is easily identifiable because it is royal blue in colour and has the consistency of velvet (the only other species it could be confused with is Chlorosplenium aeruginascens which is turquoise in colour and has similarly coloured discs).  P. caeruleum is related to the normal type of mushrooms we are familiar with but instead of having a stalk, cap and gills it form a thin film which coats branches of deciduous trees.  If someone finds what looks like royal blue paint on living deciduous trees/shrubs please inform the authors.  The information will form part of a continuing national survey, being carried out by the British Mycological Society, initiated in 1996, on the distribution of this fungus throughout Britain.

The first record of the species was made in 1813 and just over 70 sightings have been reported to date.  It does not like cold winters and has a mainly Atlantic and Mediterranean distribution in Europe.  It is only found at two sheltered fjords in Norway, is absent from Sweden and the latest Danish collection was in 1882 (Alick Henrici, British Mycological Society).  Main areas in Britain seem to be the west coast from Wales southwards, particularly the South West and especially Devon.

Host preference seems to be mainly concentrated on deciduous trees, particularly ash (nearly 50% of records) and hazel although it has occasionally been recorded on birch, box, clematis, hawthorn, beech, ivy, blackberry, willow, oak, elm and elder.  It has been found locally at Carmel Woods and the authors would appreciate records from any members of the Llanelli Naturalists.  Unfortunately there isn't a photograph of this fungus in Roger Phillips' book but there is one in Marcel Bon's publication oh page 324 under the old name of Terrana caerulea.

Please record date of find, host plant and length of fungus on twig/branch.  If in doubt on the identification then you can always send part of the specimen for confirmation to one of the authors.