Thirteen members attended the taxonomic workshop over the weekend of 31 October – 1 November at the University of East London. We were very fortunate in having the expert guidance of the distinguished Dutch bryologist, Dr Ida Bruggeman-Nannenga, who has spent many years studying the European Fissidens taxa and has built up an encyclopedic knowledge of their variation in the field. Using stained permanent slides of every European taxon, she demonstrated their essential diagnostic features with a video projection microscope, and afterwards members were able to study the slides for themselves. It was a great relief to have confirmed that members of the F. bryoides group are not always clearly defined, and would probably be better given the rank of “expression” rather than full specific or varietal status, as the morphology of several taxa tend to converge under certain habitat conditions. It was also illuminating to see how the various taxa behave in the wider context of the continent.
Dr Harold Whitehouse brought along a selection of his superb stereo-photographs of Fissidens and Tortula species, complementing Ida’s microscope slides with an indication of disposition of some of the taxa in the third dimension.
Having had such a feast on Fissidens, the ‘afters’ on Tortula brought everyone literally down to earth by concentrating on just two species and their look-alikes. The update on Hennediella macrophylla (= T. brevis) pointed out the rather sordid fact that it was apparently being spread along the banks of very mucky London streams and rivers, and on bare soil under trees in London parks, by none other than the brown rat. So far its look-alike H. standfordensis has not yet extended its range sufficiently to overlap. It was suggested that members might like to look out for evidence of it also being spread by rats, and to contemplate just how well the two might be recorded when eventually they expand their ranges and end up in mixed populations.
The other Tortula members were alerted to was T. virescens, which is turning up all over eastern England on tarmac paths, on damp brickwork, and on tombs in churchyards, and seems to be relatively uncommon on trees. On the Sunday Tim Pyner took us to Hatfield Broad Oak churchyard where it was growing in small tufts on brick tombs together with its look-alike T. intermedia. In the same churchyard a fine example of another plant that has been overlooked on stone in eastern England, Leucodon sciuroides, in two large patches on the limestone capping stones of buttresses on either side of the south door of the church. It has also been found recently on stone/brick elsewhere in Essex and in Cambridgeshire, and from the large patches present has clearly been overlooked in this habitat.
Unfortunately we were unable to visit the chalk pits in the Grays area as planned, due to problems with access. Members instead spent a pleasant sunny morning in Epping Forest looking at luxuriant patches of Zygodon forsteri, and both species of Leucobryum with capsules, as a substitute.
Kenneth J. Adams