ConservationNews Revised list of nationally rare bryophytes v Timmia megapolitana. Ron Porley

Committee, revises the list of nationally rare Table 1. Species now recorded in more than 15 10-km squares since 1950 species. It is a companion to the earlier revision A revised of scarce species (Preston, 2006) which provides H, hornwort; L, liverwort; M, moss. more background to the use of these terms. Atlas total Current total % of Atlas total The starting point for this revision is the list of nationally rare bryophyte species and subspecies H Phaeoceros carolinianus 4 17 425 list of L Barbilophozia kunzeana 10 17 170 which can be extracted from the spreadsheet of Conservation Designations for UK taxa on the L Fossombronia fimbriata 10 17 170 nationally Joint Nature Conservation Committee’s (JNCC) L Leiocolea fitzgeraldiae – 22 – website (www.jncc.gov.uk). I have brought the L Leiocolea gillmanii 13 18 138 taxonomy into line with that of the new Census L Lophozia perssonii 12 23 192 rare Catalogue (Hill et al., 2008), and updated the L Nardia breidleri 11 20 182 list to include newly discovered taxa and new L Scapania curta 15 16 107 10-km square records. The 10-km square totals L Scapania paludicola 4 19 475 bryophytes are based on records made from Britain (v.-cc. L Scapania paludosa 14 22 157 1–112) from 1950 onwards. M Bryum gemmilucens 10 20 200 The changes to the list are summarized below M Bryum knowltonii 13 19 146 and a complete new list of nationally rare species Chris Preston presents a M Bryum kunzei 8 16 200 then follows. Nomenclature follows Hill et al. M Cynodontium strumiferum 8 18 225 revised list of nationally rare (2008) with the name on the JNCC website (if it M Cynodontium tenellum 14 17 121 differs) given as a synonym in the list at the end bryophytes. of this paper. The 10-km square totals were taken M Ditrichum plumbicola 12 20 167 from the BBS database at BRC in September M Fissidens monguillonii 10 17 170 he categories ‘nationally rare’ and 2009. M Grimmia elongata 6 16 267 ‘nationally scarce’ have been used M Hedwigia ciliata – 22 – for some years in Britain as a way Species to be excluded from the list M Hypnum bambergeri 14 16 114 of identifying the most uncommon The largest group of deletions (Table 1) are M Leptodontium gemmascens 9 21 233 plants. Nationally rare taxa are those species which are now recorded in more than M Oncophorus wahlenbergii 12 17 142 Tpresent in 1–15 10-km grid squares and nationally 15 10-km squares, and these should therefore M Orthotrichum speciosum 12 20 167 scarce taxa those in 16–100 squares. These be transferred to the list of scarce species. The M Philonotis tomentella 13 19 146 categories are distinct from measures of threat, number of squares in which the species was M Physcomitrium sphaericum 14 21 150 such as Critically Endangered, Endangered, mapped from 1950 onwards in the Atlas of M Pohlia andalusica 12 16 133 Vulnerable and Near Threatened, which are Bryophytes (Hill et al., 1991–94) and the current M Pseudoleskeella rupestris 12 18 150 assessed using the internationally agreed IUCN total give an indication of the extent to which the M Racomitrium macounii 10 21 210 criteria. Rare and scarce attributions are less species was previously under-recorded. M Sanionia orthothecioides 5 61 1220 important than these designations, but are The greatest increases reflect species where M Sciuro-hypnum glaciale 14 16 114 nevertheless useful in selecting SSSIs, drawing bryologists have made a special effort to get to M Sciuro-hypnum reflexum 14 20 143 up rare plant registers and highlighting the know plants and systematically survey likely M Sphagnum majus 3 21 700 n Fig. 1. Sanionia orthothecioides, ‘special species’ in areas ranging from counties to habitats. Sandy Payne has walked the coastlines a species now removed from the M Sphagnum riparium 15 36 240 small nature reserves. This paper, prepared at the of northern Scotland in search of Sanionia ortho- ‘rare’ list thanks to systematic request of the BBS Conservation and Recording thecioides (Figs 1 & 2), showing that it is much M Tortula freibergii 5 34 680 survey work. Effy Everiss

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Table 4. Species to be added as a result of taxonomic revision more frequent (especially around the convoluted , Fig. 2. Known distribution of Native species to add to the list or other reasons coast of Shetland) than was suspected when it Sanionia orthothecioides. The native species in Table 3 have recently been was reported, new to Britain, in 1992. He is also added to the British list. They all seem likely to M Acaulon mediterraneum Upgraded from variety primarily responsible for the 700% increase in be genuinely rare, although as some of the above L Fossombronia mittenii Extinct but with a post-1950 record records of Sphagnum majus. Similarly, Tortula examples show, our initial impressions of the freibergii has been systematically recorded along rarity of species sometimes have to be modified M Grimmia alpestris Reinstated on British list the canals of north-west England by Locksley in the light of later experience. M Grimmia anodon Formerly feared extinct (2007) and Callaghan (2008). These examples M Pterygoneurum lamellatum Extinct but with a post-1950 record show how effective it can be to adopt and record Table 3. Native species to add to the list M Schistidium atrofuscum Perhaps omitted in error ‘pet’ species. M Tortula schimperi Upgraded from variety and M Arctoa anderssonii Several of the other species have been dis- taxonomic concept refined M Bruchia vogesiaca covered in Britain only recently. These include M Dialytrichia saxicola some added to the British list in the 1990s such (Long, 2008). Like G. sessitana, it is retained on as Leiocolea fitzgeraldiae (described in 1995), M Ephemerum hibernicum the list on the basis of different specimens from Hedwigia ciliata (not separated by British bryolo- M Orthotrichum acuminatum those which caused it to be added originally, as gists from the much more frequent H. stellata M Orthotrichum consimile the latter were all misidentifications. It seems until 1995) and Racomitrium macounii (first M Schistidium flaccidum worth adding, for the sake of completeness, recognized here in 1991). Others have been M Seligeria oelandica Fossombronia mittenii and Pterygoneurum known rather longer but are small, very incon- M Timmia megapolitana lamellatum, two species which have post-1950 spicuous and genuinely very uncommon, includ- M Tortula inermis records but are feared extinct. ing Ditrichum plumbicola (described in 1976), The total number of additional native species Fossombronia fimbriata (described in 1974) and Four of these, Arctoa anderssonii (Rothero, is 17. Lophozia perssonii (reported new to Britain in 2009), Orthotrichum acuminatum (Blockeel, 1968). Phaeoceros carolinianus is a much more 2009), Seligeria oelandica (Bosanquet, 2009) Alien species conspicuous plant, but it has been confused with and Tortula inermis (Blockeel et al., 2009) were It is more difficult to identify introductions in the very similar P. laevis, and Bryum kunzei was published after the preparation of the new bryophytes than flowering plants as they have neglected until it was treated as a species rather Census Catalogue. Seligeria oelandica has long much greater powers of long-distance dispersal. than as var. imbricatum of B. caespiticium. Only been known from Ireland, and Ephemerum hib- They are almost never deliberately spread by Orthotrichum speciosum of the above species is subspecies are listed as nationally rare, so those ernicum was described from Ireland in 2005; people, unlike (for example) vascular plants which genuinely increasing in frequency. reduced to variety should be removed from the both have recently been found in Wales by Sam are imported for horticultural reasons and which A few species have to be deleted as the result of list. Bosanquet. Orthotrichum acuminatum may be a therefore have a clear introduction pathway. In taxonomic research (Table 2). Only species and This gives a total of 40 deletions. ‘native casual’, a plant which arrived by natural general, bryophytes can only be recognized as means but has not persisted. aliens in Britain if they come from distant con- Table 2. Species deleted as a result of taxonomic research A few species have to be added because of tinents, and even then their status is likely to be taxonomic revision, or for miscellaneous other doubtful unless their means of introduction is M Bryum archangelicum Now includes the much commoner B. imbricatum reasons (Table 4). clear. The JNCC spreadsheet omits such recently M Bryum neodamense Now reduced to a synonym of B. pseudotriquetrum var. pseudotriquetrum Grimmia anodon, once feared extinct, still established, alien species. While this is a perfectly M Didymodon mamillosus Now reduced to a synonym of D. rigidulus survives in Edinburgh (Long, 2006). The reasonable course of action for a conservation M Grimmia ungeri British material has been re-identified asG. montana recent history of Grimmia alpestris in Britain is organization to take, it seems worth adding them M Hymenostylium insigne Now reduced to a variety of H. recurvirostrum (and in any event now known from 19 squares) a confusing story of changing determinations, to the list (with an appropriate annotation) for M Pictus scoticus Now reduced to a synonym of Hygrohypnum luridum but it is now regarded as genuinely British those who would like to use the list of rare species

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for other purposes. The following can be listed as Doubtful cases rare aliens or putative aliens. British bryologists are still working out the distribution of the species of Schistidium defined Table 5. Rare aliens or putative aliens by H.H. Blom in his monograph of the S. apo- carpum complex and introduced to most British M Achrophyllum dentatum bryologists by Smith (2004). S. atrofuscum is M Bryum apiculatum included amongst the additions to the JNCC M Bryum valparaisense list above (Table 4) as it has been known from M Calyptrochaeta apiculata Britain since 1957 and is clearly very uncommon. M Leptophascum leptophyllum S. flaccidum has also been added to the list on L Lophocolea brookwoodiana the advice of Sam Bosanquet, who regards it as L Riccia crystallina a very distinctive species which has only been L Riccia rhenana found twice, and so is likely to be genuinely rare. L Telaranea murphyae Four other species are currently known from L Telaranea tetradactyla fewer than 16 squares, S. dupretii, S. flexipile, S. M Thamnobryum maderense papillosum and the very recent addition to the M Tortula amplexa British list S. helveticum (Blockeel et al., 2009). It seems best to wait before adding these to the n Most of these are more or less obvious intro- list of rare species until their distributions are Fig. 3. Seligeria patula. David Holyoak ductions even if (as with Lophocolea brook- clarified. Grimmia muehlenbeckii, reinstated on under-recording is an even greater problem, and sites, new localities are only likely to be found woodiana and Telaranea murphyae) their native the British list in 1997, seems likely to be under- a long period is needed to ensure that we have by general recording and we are likely to range is unknown. Two are more doubtful. recorded rather than genuinely rare, as it is adequate national coverage and that species are become aware of extinctions more rapidly than Bryum apiculatum is a tropical/subtropical, already known from six Scottish vice-counties not included on the list simply because they colonizations. weedy species recently found by David Holyoak (Hill et al., 2008). Dicranum flexicaule, the recent- are under-recorded. The BBS Conservation A further question relates to the frequency (2009) in East Cornwall, new to Europe, where ly upgraded D. fuscescens var. congestum, is even & Recording Committee has suggested that with which these lists are reviewed. With the it appears to have been spread by motor vehicles. more likely to be under-recorded. We do not a more fundamental revision of the rare and increasing flow of data electronically to the BBS, Its status as a native or alien may become yet have a detailed account of the distribution scarce lists, with a later cut-off date, should await the totals on which our assessments are based clearer if further populations are discovered. in Britain of Moerckia hibernica (now separated the publication of the proposed new Atlas of are updated regularly, and it becomes feasible Thamnobryum maderense is a particularly doubt- from M. flotoviana) and of the two species which Bryophytes (see Preston et al., 2009, for details of to revise lists such as those of rare and scarce ful case as the taxonomy of the species requires have until recently been included under Seligeria this). The IUCN threat criteria should identify species annually. However, if they are to be used clarification, and a final assessment is obviously trifaria, S. trifaria sens. str. and S. patula (Fig. 3). species which are rapidly declining and ensure for planning local rare plant registers or assessing impossible until we have a clearer idea of its that they have the appropriate conservation the importance of sites, a degree of stability in British and European distribution. Discussion designations. these lists is essential. We need to decide on a There may well be other species of bryophyte Records made from 1950 onwards are included Leptodontium gemmascens (Fig. 4) has been the compromise between the desire to be up-to-date which are listed amongst the native rare species in the above totals, and some may therefore subject of an exemplary study by Porley (2008), and the need to avoid constantly tinkering with but which were actually introduced, in some be nearly 60 years old. Species such as Bryum which highlights another aspect of this problem. the list. cases perhaps in ancient times. Obvious examples knowltonii and Tortula wilsonii have declined Its known sites have been thoroughly surveyed include those associated with heavy metal since 1950 and are probably now present in fewer in recent years and it is known from 15 10-km The revised list workings such as Cephaloziella massalongi and than 15 squares, even though they do not qualify squares since 1990 and 10 since 2000. However, Once the changes outlined above are imple- Scopelophila cataractae, as well as the puzzlingly for the nationally rare list on the basis of the total it is a species which clearly has a rather dynamic mented, the revised list of nationally rare species rare and disjunct liverwort Lophozia herzogiana. from 1950 onwards. However, for most species distribution, and although we can resurvey old is as presented in Table 6.

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Table 6. Revised list of nationally rare bryophytes Dicranum leioneuron Mnium spinosum Scopelophila cataractae Alien or probably alien species are indicated by an asterisk (*) and species which have been recorded since 1950 but are now Didymodon cordatus Myurella tenerrima Seligeria brevifolia feared extinct by an obelus (†). Didymodon glaucus Orthodontium gracile Seligeria campylopoda Didymodon icmadophilus †Orthotrichum acuminatum Seligeria carniolica Liverworts (54) Ditrichum cornubicum Orthotrichum consimile Seligeria diversifolia Ditrichum subulatum Orthotrichum gymnostomum Seligeria oelandica Adelanthus lindenbergianus Gymnomitrion corallioides Odontoschisma macounii Entosthodon pulchellus Orthotrichum obtusifolium Sematophyllum demissum Anastrophyllum alpinum Herbertus delavayi (H. borealis) Plagiochila norvegica Funaria pulchella Orthotrichum pallens Sematophyllum substrumulosum Anastrophyllum joergensenii Jamesoniella undulifolia Radula carringtonii ( ) Ephemerum cohaerens Orthotrichum pumilum Sphagnum balticum Anastrophyllum saxicola Jungermannia polaris Riccia bifurca Ephemerum hibernicum Palustriella decipiens Sphagnum skyense Athalamia hyalina Leiocolea rutheana Riccia canaliculata Eurhynchiastrum pulchellum Paraleucobryum longifolium Stegonia latifolia Barbilophozia quadriloba Lejeunea eckloniana (L. holtii) *Riccia crystallina Eurhynchium pulchellum Philonotis cernua Syntrichia norvegica Cephalozia ambigua Lejeunea mandonii Riccia nigrella ( ) Fissidens curvatus Philonotis marchica Tayloria lingulata Cephaloziella baumgartneri Liochlaena lanceolata *Riccia rhenana Fissidens serrulatus Physcomitrium eurystomum Tayloria tenuis Cephaloziella calyculata (Jungermannia leiantha) Scapania gymnostomophila Grimmia alpestris Plagiobryum demissum Tetrodontium repandum Cephaloziella dentata *Lophocolea brookwoodiana Scapania parvifolia Grimmia anodon Plagiomnium medium Thamnobryum angustifolium Cephaloziella elachista Lophozia herzogiana Scapania praetervisa Grimmia arenaria Plasteurhynchium meridionale Thamnobryum cataractarum Cephaloziella integerrima Lophozia longiflora Solenostoma caespiticium Grimmia crinita (Eurhynchium meridionale) *Thamnobryum maderense Cephaloziella massalongi Lophozia wenzelii (Jungermannia caespiticia) Grimmia elatior Pohlia crudoides Timmia austriaca Dumortiera hirsuta Marsupella arctica Southbya nigrella Grimmia sessitana Pohlia obtusifolia Timmia megapolitana †Fossombronia mittenii (F. crozalsii) Marsupella boeckii Southbya tophacea Grimmia tergestina Pohlia scotica Timmia norvegica Geocalyx graveolens Marsupella condensata Telaranea europaea (T. nematodes) Grimmia unicolor Pseudocalliergon turgescens Tortella fragilis Gongylanthus ericetorum Marsupella profunda *Telaranea murphyae Heterocladium dimorphum (Scorpidium turgescens) *Tortula amplexa Gymnocolea acutiloba Marsupella sparsifolia *Telaranea tetradactyla (T. longii) Homomallium incurvatum Pseudoleskea incurvata Syntrichia amplexa Gymnomitrion apiculatum Nardia insecta ( ) Hygrohypnum molle Pseudoleskeella nervosa Tortula cernua Hygrohypnum polare †Pterygoneurum lamellatum Tortula cuneifolia Mosses (146) Hygrohypnum smithii Ptychodium plicatum Tortula inermis Acaulon mediterraneum Brachythecium cirrosum Buxbaumia viridis Hygrohypnum styriacum Racomitrium himalayanum Tortula leucostoma Acaulon triquetrum (Cirriphyllum cirrosum) *Calyptrochaeta apiculata Hypnum revolutum Rhynchostegium rotundifolium Tortula schimperi *Achrophyllum dentatum Brachythecium erythrorrhizon Campylophyllum halleri Hypnum vaucheri Rhytidiadelphus subpinnatus Tortula solmsii Amblystegium radicale Bruchia vogesiaca Campylopus subporodictyon *Leptophascum leptophyllum Saelania glaucescens Tortula vahliana Andreaea alpestris Bryoerythrophyllum caledonicum (Dicranum subporodictyon) (Chenia leptophylla) Schistidium atrofuscum Weissia levieri Andreaea blyttii *Bryum apiculatum Ceratodon conicus Micromitrium tenerum Schistidium flaccidum Weissia multicapsularis Andreaea frigida Bryum arcticum Cheilothela chloropus Mielichhoferia elongata Sciuro-hypnum starkei Zygodon forsteri Andreaea sinuosa Bryum calophyllum Cinclidotus riparius Mielichhoferia mielichhoferiana (Brachythecium starkei) Zygodon gracilis Anomodon attenuatus Bryum cyclophyllum Ctenidium procerrimum Mnium lycopodioides (M. ambiguum) Anomodon longifolius Bryum dyffrynense Cyclodictyon laetevirens Aongstroemia longipes Bryum gemmiparum Cynodontium polycarpon Aplodon wormskioldii (‘wormskjoldii’) Bryum marratii Daltonia splachnoides Arctoa anderssonii Bryum muehlenbeckii Dendrocryphaea lamyana Acknowledgements Threatened Bryophyte Database managed by Nick Hodgetts Bartramia stricta Bryum salinum (Cryphaea lamyana) Grateful thanks are due to all the bryologists who contribute and funded by JNCC, Natural England, Countryside Council the records on which this assessment is based, and to the Centre for Wales and Scottish Natural Heritage. Special thanks are Blindia caespiticia Bryum schleicheri Dialytrichia saxicola for Ecology and Hydrology and Joint Nature Conservation due to Sandy Payne for supplying many of the recent records Brachytheciastrum trachypodium Bryum uliginosum Dicranella grevilleana Committee for jointly funding the BRC database where of Sanionia orthothecioides incorporated into Fig. 2. I am (Brachythecium trachypodium) *Bryum valparaisense Dicranum elongatum they are housed. The database incorporates records from the grateful to Sam Bosanquet, Tom Blockeel, Mark Hill, Nick

38 FieldBryology No100 | Feb10 FieldBryology No100 | Feb10 39 n Fig. 4. Leptodontium gemmascens. Ron Porley

Hodgetts, David Holyoak, Ron Porley and Gordon Rothero 94). Atlas of the Bryophytes of Britain and Ireland. 3 vols. of the BBS Conservation and Recording Committee for their Colchester: Harley Books. comments on a draft of this note. Hill, M.O., Blackstock, T.H., Long, D.G. & Rothero, G.P. (2008). A Checklist and Census Catalogue of British and Irish C.D. Preston Bryophytes. Updated 2008. Middlewich: British Bryological CEH Wallingford, Benson Lane, Crowmarsh Society. Gifford, Wallingford, Oxfordshire OX10 8BB Locksley, A.R. (2007). Tortula freibergii along the Bridgewater (e [email protected]) Canal. Field Bryology 93, 8–10. Long, D.G. (2006). Grimmia anodon rediscovered on Arthur’s References Seat. Field Bryology 88, 2–3. Blockeel, T.L. (2009). A transient occurrence of Orthotrichum Long, D.G. (2008). Grimmia updates. Field Bryology 95, acuminatum H. Philib. in Derbyshire, a new British moss. 16–20. Journal of Bryology 31, 47–49. Porley, R.D. (2008). Threatened bryophytes: Leptodontium Blockeel, T.L., Rothero, G.P. & Long, D.G. (2009). Tortula gemmascens. Field Bryology 96, 14–25. inermis and Schistidium helveticum, two mosses from Preston, C.D. (2006). A revised list of nationally scarce bryo- Scotland, new to the British Isles. Journal of Bryology 31, phytes. Field Bryology 90, 22–30. 174–179. Preston, C.D., Hill, M.O., Bosanquet, S.D.S. & Ames, S.L. Bosanquet, S. (2009). Wildlife reports. Bryophytes. British (2009). Progress towards a new Atlas of Bryophytes. Field Wildlife 20, 367. Bryology 98, 14–20. Callaghan, D.A. (2008). Scale dependency and area of occu- Rothero, G.P. (2009). Arctoa anderssonii Wich. (Dicranaceae), pancy: Tortula freibergii in north-west England. Journal of new to the British Isles. Journal of Bryology 31, 76–79. Bryology 30, 279–282. Smith, A.J.E. (2004). The Moss Flora of Britain and Ireland, 2nd Hill, M.O., Preston, C.D. & Smith, A.J.E. (editors) (1991– edn. Cambridge: Cambridge University Press.

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