Field Bryology number 90

Recent work on Hafllatocaulis vernicosus in mid and south

Sam D.S. Bosanquet\ Alan D. Hale, Graham S. Motley & Ray G. Woods

1 Countryside Councilfo r Wales) Llanion House) Llanion Park) Pembroke Dock) Pembrokeshire) SA 72 6DY

Background its inclusion on the European lists, it was given special protection by addition to Schedule 8 of Perception of the status of vemicosus the Wildlife and Countryside Act; finally, in in Britain fluctuated considerably during the 20th 199 5, it was listed as a priority species in the UK century. For many years (as Drepanocladus Biodiversity Action Plan. The Action Plan for vemicosus) it was thought to be a widespread and the species (Anon, 199 5) stated that it had been not uncommon species of flushes and fens recorded at 70 sites in Britain. throughout much of Britain. Smith (1978), for example, described it as 'generally distributed, In order to begin to clarify the status of H. occasional' and noted that it had been recorded vemicosus in Britain, Tom Blocked was in 46 vice-counties in Great Britain. Then, in contracted by the Joint Nature Conservation 1989, Lars Hedenas published a critical revision Committee GNCC) to re-examine all available of the of the genera 5 corpidium and material from British collections (Blocked, Drepanocladus, and introduced a new genus, 1997). This study showed that around one-third Hamatocaulis, to which he transferred D. vemicosus of material collected as D. or H. vemicosus was in (Hedenas, 1989). This paper demonstrated that fact misidentified, 5. cossonii being the most there had previously been frequent confusion of frequent species with which it had been H. vemicosus with other related species, in confused. particular5 corpidium cossonii. Identification At this stage it was impossible to know the true status and distribution of the newly-defined Confusion over the identification of H. vemicosus taxon in Britain, or in Europe outside of seems to have resulted primarily from the lack Fennoscandia. Nonetheless, it was listed (as D. of recognition of 5. cossonii at any taxonomic vemicosus) on a number of international and level in Britain until recently. 5. cossonii often domestic lists that implied a threat and a need looks dramatically different from the more for protection. Thus, in 1991, it was added to familiar, robust, dark red 5. revolvens, and Appendix I of the Council of Europe sometimes has faintly plicate leaves. The brevity Convention on the Conservation of European of the description of 5. cossonii (as Drepanocladus Wildlife and Natural Habitats (commonly revolvens var. intermedius) in Smith (1978), coupled referred to as the Bern Convention); in 1992 it with the reliance on the presence/ absence of was included on Annex lib (species for which plicae in that Flora's key, might have led Special Areas of Conservation should be recorders to misidentify it as H. vemicosus. A lack selected) of the European Community Habitats of good photographs in the public domain Directive; also in 1992, and largely as a result of means that, even now, few British bryologists

2 Hamatocaulis vernicosus in Wales are familiar with H. vernicosus, and the key in the cells. With familiarity, the vast majority of most recent edition of Smith's Flora (Smith, of H. vernicosus can be identified in the field. As 2004) still relies on the presence of at least faint the species is listed on Schedule 8 of the Wildlife plicae to identify the genus Hamatocaulis. and Countryside Act 1981, a licence is required to knowingly collect it for verification. Gaining H. vernicosus is at least as distinctive in the necessary familiarity can thus be rather appearance (Figure 1) as its former congeners difficult. that are now housed in Drepanocladus, Sanionia and Warnstoifia, and only the most depauperate plants should cause confusion. It has pinnately branched stems, with the branches usually projecting at a 90° angle, and falcate leaves. Leaf bases are relatively wider than in closely related species, giving the stem a wide-backed appearance that contrasts with the narrow­ backed stems of W exannulata. Although H. vernicosus has something of a shine, S. cossonii looks much shinier and smoother in the field, as well as having a more tidy overall appearance. The red leaf bases of H. vernicosus are usually apparent, although this varies slightly during the year, perhaps as the plants grow. Well-grown Figure 1. Hamatocauiis vernicosus: general appearance of plants tend to have a concentration of red fresh material. pigmentation on the curve of the hooked stem apex, forming a rectangle of colour that is often Distribution, status and ecology of striking in the field. Leaf plicae are usually clearly Harnatocaulis vernicosus in mid and south visible, sometimes highlighted by lines of red Wales pigment. W exannulata sometimes has faintly plicate leaves or hints of a red leaf base, but its Recent fieldwork by the authors and others has narrow-backed stems and longer, narrower clarified the distribution, status and ecology of leaves make it look quite different. Overlapping H. vernicosus in Wales, in particular mid and leaves in this species and S. cossonii sometimes south Wales. A distribution map of H. vernicosus give the impression of plicae in the field. in Wales is presented in Figure 2. Figure 3 shows Confusion with Palustriella fa lcata can also occur, a typical habitat for the species. but that species has abundant paraphyllia that can be seen in the fieldthrough a x20 hand lens. The hotspots for H. vernicosusin south Wales are a) the massifs of Mynydd Du and Mynydd Microscopic confirmation of the identification Myddfai on the Carmarthenshire (v.-c. of H. vernicosus is provided by the stem section 44)/Breconshire (v.-c. 42) border, and b) the and leaf base. The stem has a neat epidermis of hills of Mynydd Preseli in Pembrokeshire (v.-c. cells with walls of a uniform thickness, unlike 45). the thin-walled hyalodermis of S. cossonii, and lacks the central strand that is present in that Twenty-two records of H. vernzcosus from species. The stem of W exannulata also lacks a Mynydd Du, made by SDSB and GSM between hyalodermis, but that species is easily 2000 and 2003, together with 39 new records distinguished from H. vernicosus under the made by Johnny Turner, were summarised in microscope on account of its large, hyaline alar Turner (2003). There are five main clusters of

3 Field Bryology number 90

Dicranella palustris, Phzlonotis fo ntana, Rhytidiadelphus squarrosus and S corpidium cossonii were associates in more than 20% of samples. Agrostis stolonifera, Carex nigra, C.panicea, ]uncus acutzflorus and Montia fo ntana were among the most regular vascular associates. Mynydd Du SSSI protects five flushes holding H. vernicosus, but most flushes in which it is present are below the 450 m contour that forms most of the boundary of the site. Waun Ddu SSSI protects three small colonies of H. vernicosus, but several much larger patches lie in adjacent moorland outside the SSSI boundary.

Figure 2. 10-km square distribution of Hamatocaulis vernicosus in Wales. Pale dots represent pre-1980 records. records and a few outliers. Most clusters include at least one or two sub-populations numbering thousands of stems, with the largest, on Mynydd Figure 3. Typical habitat for Hamatocaulis vernicosus, Bach Trecastle, including at least three discrete associated here with Sphagnum contortum in a neutral flush. flushes, each of which holds over 10,000 stems of H. vernicosus covering areas of more than The second south Wales hotspot, in 30m2. The colonies are distributed along the Pembrokeshire (v.-c. 45), is centred on Mynydd outcrop of Devonian and Preseli SSSI (Preseli SAC), which holds colonies similar Red Sandstones of Silurian age that form numbering thousands of plants, with smaller the northern half of Mynydd Du, and are colonies elsewhere in the north-east of the vice­ concentrated in gently sloping valleys, usually county. Most colonies of H. vernicosus on below 400 m altitude. There is considerable Mynydd Preseli are associated with bryophyte­ variation in base-status in flushes on the Old dominated, domed springheads where water Red Sandstone, but most appear to be too base­ bubbles up through gently sloping wet heath. rich for H. vernicosus, supporting instead Others on Mynydd Preseli, and all those Palustriella commutata, S. cossonii, S. revolvens or S. elsewhere in the vice-county, are either in fens scorpioides. H. vernicosus occurs primarily on flat that have developed in small hollows ground on valley floors where base-rich water (sometimes pingos) or in flushes on moderately from steeper flushes spreads and mixes with steep ground. The species was recorded in two more acidic water. Quaking springheads in open quadrats during CCW's survey of lowland moorland also support a few colonies. grasslands in the county (Bosanquet, Smith & Calliergonella cuspidata was the only constant Stevens, 2006) and in four quadrats during a bryophyte associate in 38 quadrats sampled by vegetation survey of Mynydd Preseli. Three of Turner (2003), whilst Chilosryphus pallescens, these stands had constant Carex rostrata above a

4 Hamatocaulis vernicosusin Wales neutral bryophyte layer, and are referable to the but all are small. Slightly basic flushes below the Carex rostrata - Sp hagnum squarrosum mire (MS) 450 m contour provide the major habitat for this (Rodwell, 1991) but the others could not be . Its associated species here mirror closely adequately housed in the National Vegetation those noted on Mynydd Preseli, with the Classification. Constant associates were the addition of Galium ulig inosum, Lotus pedunculatus vascular plants Agrostis canina, Anagallis tenella, and Molinia caerulea. An average of 20 associated Carex echinata, C. panicea, Galium palustre, Juncus species have been noted from quadrats of acutiflorus and ]. bulbosus and the moss various sizes up to 4 m2 placed around H. Calliergonella cuspidata, whilst Aneura pinguis, vemicosus. Ten measurements of the pH of spring Sp hagnum contortum, S. flexuosum and S. teres were water bathing these flushes at sites in north regularly present. Mynydd Preseli SSSI protects Breconshire show a range from 5.9 to 6.6. The 19 of the 37 known colonies of H. vemicosus in lowest pH noted was 5.7 from a north Pembrokeshire, including all but one of the Radnorshire site. The Ministry of Defence army colonies with more than 1,000 plants. Four training area of in north other Pembrokeshire SSSis hold smaller Breconshire, which has entirely escaped post­ colonies of the species and only nine colonies WWII agricultural intensification, supports the are known from unscheduled land. only significant populations of this moss not on common land. Four populations are protected The much-studied colony of H. vemicosus at Rhos by SSSI and SAC designation, although they Llawr-cwrt was the only one known in remain slightly vulnerable to damage from troop Cardiganshire (v.-c. 46) until the late 1990s. The training and exploding ordnance. Elsewhere in site is now notified as an SAC, with H. vemicosus mid Wales the grant-aided drainage of flushes on as one of its qualifying features. ADH found a inby land on the lower hill slopes must have second colony in flushes at Soar y Mynydd in destroyed countless populations of the species. 1997, and a third was added by SDSB and GSM GSM has recently found several additional in the Doethie Valley in 2001. These sites lie colonies in the central part of the close to the Mynydd Mallaen/Rhandirmwyn Beacons National Park. The greatest density of area of north-eastern Carmarthenshire, where H. sites is on moorland around the head of the vemicosus has been known since the early 20th River Hepste, just west of the A470 trunk road. century and is still present in a few scattered Here, eight scattered colonies were found during places. During a visit to Cwm Ystwyth with a rapid vegetation survey of the area. Coupled Arthur Chater in 2004, SDSB found the fourth with additional casual records from contiguous and fifth Cardiganshire colonies of H. vemicosus, moorland further east and west, it seems that both of them comprising thousands of plants. this area may prove to be as much of a hotspot These, together with records from Breconshire, as Mynydd Du and Preseli. The geology of this raise the possibility that other large colonies are area is composed mainly of Devonian Old Red currently undetected in remote parts of the Sandstones, as on Mynydd Du. . There are also a few colonies of H. vemicosus in Most of the Breconshire (v.-c. 42) and the central around Pen-y-fan, Radnorshire (v.-c. 43) colonies of H. vemicosus including one at an altitude of 630 m altitude, have been located by RGW since the late 1990s. below Cribyn. This would appear to be the RGW was even prepared in the early days to highest recorded altitude for the species in drag a compound microscope across military Britain. training areas and cut stem sections in the field! Most colonies are on Mynydd Epynt and H. vemicosus is not listed for Glamorgan (v.-c. 41) commons near Abergwesyn and in mid Radnor, in Blocked & Long (1998) and its distribution

5 Field Bryo!ogy number 90 there is rather uncertain. The only record In all, H. vernicosus has been recorded in 20 mentioned in Perry (1994), from Llangennith hectads in north Wales, and within 11 of those Burrows, was re-determined by Tom Blocked. since 1980. Several locations for pre-1980 SDSB has seen two small colonies at Gors records have yet to be re-surveyed for the Llwyn, Onllwyn SSSI, and these appear to species and it seems likely that more extensive constitute the only vice-county records. There general recording would reveal further sites. are, as yet, no confirmed records from the south Wales Coalfield, but flushes in this area support SACs for Hamatocaulis vernicosusin Wales other bryophytes of neutral flushes, such as Sp hagnum subsecundum and S. teres, so H. vernicosus The first European Special Areas of might be expected to occur. Conservation (SACs) for H. vernicosus were selected in the mid-1990s, of necessity on the Distribution and status of Hamatocaulis basis of rather flimsy evidence. By the time a vernicosus in north Wales second tranche of sites was required in the late 1990s, the situation had improved to some Recent survey coverage in north Wales has not extent, but the Countryside Council for Wales been as comprehensive as in the south, and as a (CCW) nonetheless commissioned surveys to result we do not have as complete a picture of confum the presence of the species in certain the distribution of H. vernicosus here. Most proposed SACs. Thus, in 1999, David Holyoak locations are in the north-west, in Merioneth refound it at two locations within Corsydd (v.-c. 48) and Caernarvonshire (v.-c. 49). The Eifionydd in Caernarvonshire (Holyoak, 1999); Merioneth records are clustered on the lower in 2002, Nick Hodgetts confumed its presence slopes of Cadair Idris SAC near Dolgellau, and at one of two previously known locations in the south of Barmouth; these are mostly from foothills of Eryri (Snowdon) (Hodgetts, 2002). A Peter Benoit in the 1970s, but tl1.e continued total of four SACs in Wales have now been presence of H. vernicosus within Cadair Idris selected with H. vernicosus as a primary feature. SAC was confumed by SDSB and ADH in These are Corsydd Eifionydd and Eryri (north 2003. Other populations occur west of Bala Wales), Mynydd Epynt (mid Wales) and Preseli within the extensive upland block now (south-west Wales). In two other SACs it is comprising the Migneint-Arenig-Dduallt SAC. listed as a qualifying feature, but not as a primary In Caernarvonshire, records occur within the reason for site selection. These are Cadair Idris Eryri (Snowdon) SAC and in the fen sites (north Wales) and Rhos Llawr-cwrt (west making up the Corsydd Eifionydd SAC. Wales). Further details may be found on the Populations in Eryri, Migneint-Arenig-Dduallt JNCC website (www.jncc.gov.uk) under and Corsydd Eifionydd SACs have been 'protected sites'. confumed and described by recent CCW­ funded surveys. Current status of Hamatocaulis vernicosus in England, Scotland and Ireland There is a scattering of records elsewhere in north Wales: Montgomeryshire (v.-c. 47), one In England, H. vernicosus has been recorded from hectad, not recorded since 197 4; Denbighshire 32 hectads, six of them post-1980. In Scotland, (v.-c. 50), three hectads (the most recent records it is recorded from 20 hectads, 14 post-1980, are from Mynydd Hiraethog SSSI in 2001); and in the whole of Ireland from 29 hectads, Anglesey (v.-c. 52), one hectad (fust recorded in five post-1980. These figures might appear to 1974 and confumed by SDSB in 2005). There indicate a significant decline, but could just as are no confumed records from Flintshire (v.-c. easily indicate a lack of recent survey by 51). recorders skilled in recognising the species and

6 Hamatocaulis vernicosusin Wales its habitat. A severe decline in East Anglia is, rather dull and is unlikely to normally generate however, certainly genuine. the search effort needed to locate the species. In Scotland and the north of England such low­ Current status of Hamatocaulis vernicosus altitude flushes are likely to be speedily bypassed in Europe on the way to more interesting higher ground. It is nevertheless essential to settle the question as The wider distribution of H. vemicosus in Europe to whether this is a truly threatened species or is incompletely known and, as in Britain, has just a widely overlooked one. The resources hotspots that seem to reflect local recorders' available for bryophyte conservation are sparse knowledge of the species as much as its true and can ill afford to be wasted. Its ecology and distribution. In Sweden it is widespread to life-history remain little-known, as perhaps too frequent in some parts of the north, but has is its world and European distribution and declined in the south, probably due to status. Although probably not threatened in hydrological and management changes (L. Britain it is not impossible that the British Isles Hedenas, pers. comm.). It is also reasonably might hold a significant population in global widespread in Switzerland (http:// terms. www.nism.unizh.ch/map) and Estonia (N. Ingerpuu, pers. comm.). There are strong Finally, one recent and intriguing discovery is populations, described as 'very abundant', in the that H. vernicosus comprises two genetically Auvergne and in eastern France, but most distinct clades (Lars Hedenas, pers. comm.). So French colonies are 'rather small' (y. Hugonnot, far, no correlation has been found between pers. comm.). Investigation of its distribution these genetic groups and the taxon's and ecology is currently underway in Denmark morphological variation. The first clade has (L. Hedenas, pers. comm.), the Czech Republic been found in Minnesota, northern and (T. Stechova, pers. comm.), Spain (P. Heras and southern Sweden and Switzerland, whilst the M. Infante, pers. comm.) and several other second has so far only been detected in European countries. In the Netherlands, where southern Sweden and Switzerland. How British it was thought extinct, it has recently been plants fit this pattern is currently unknown, but refound at a single location (L. Hedenas, pers. it is conceivable that the locally common Welsh comm.). Despite the patchy nature of our plants might represent the first clade, whilst the current knowledge there does not seem to be severely depleted East Anglian colonies might any evidence that H. vernicosus is threatened in represent the rarer second clade. If south Wales Europe. plants belong to the rarer second clade then they would be of considerably more Conclusions importance in a global context than if they are examples of the fust clade. Focused and unrelenting searching for H. vernicosus in mid and south Wales has Acknowledgements demonstrated its widespread occurrence in the region. A growing appreciation of its habitat SDSB's colleagues Diane Dobson, Dave Reed, requirements has undoubtedly improved our Stuart Smith and Alex Turner all found colonies success in locating it. The frequency of its of H. vemicosus during the Pembrokeshire Phase occurrence in this area must now raise a II survey of lowland grasslands. Lars Hedenas question as to whether its current conservation provided useful information during and after the grading is justified. It may yet prove to be more workshop in Cambridge in widespread than it currently appears in other 2005 and provided helpful comments on a parts of the UK. Its flush habitat is bryologically manuscript of this paper.

7 Field Bryology number 90

References Hodgetts NG. 2002. Survey for the moss Hamatocaulis vernicosus on Eryri SSSI/ cSAC. Countryside Council for Wales Science Report. Anon.1995. Biodiversity: the UK Steering Group Report. Volume Holyoak DT. 1999. Status, ecology and conservation ofthe moss 2. Action Plans. London: HMSO. Hamatocaulis vernicosus in Englandand Wales. Countryside Blockeel TL. 1997. A revision of British specimens of Council for Wales and English Nature Science Report. Drepanocladus vernicosus. Peterborough: Joint Nature Perry AR. 1994. Hornworts, liverworts and of Conservation Committee. Glamorgan. In: Wade AE, Kay QON, Ellis RG, eds. Blockeel TL, Long DG. 1998. A check-fist and census Flora ofGlamorgan. London: HMSO, 219-248. catalogue of British and Irish bryophytes. Cardiff: British Rodwell JS. 1991. British communities. Volume 2. Mires Bryological Society. and heaths. Cambridge: Cambridge University Press. Bosanquet SDS, Smith SLN, Stevens DP. 2006. A Smith AJE. 1978. The moss flora ofBritain and Ireland, 1'1 ed. vegetation survey and conservation assessment of lowland Cambridge: Cambridge University Press. grassfands in Pembrokeshire. Bangor: Countryside Council Smith AJE. 2004. The moss flora ofBritain and Ireland, 2nd ed. for Wales. Cambridge: Cambridge University Press. Hedenas L. 1989. The genera Scorpidium and TurnerJ. 2003. Surveyfor the moss Hamatocaulis vernicosus Hamatocaufis, gen. nov., in northern Europe. Lindber;gia on lvfynyddDu and Waun Ddu, Brecknock and Carmarthen. 15: 8-36. Countryside Council for Wales Science Report.

Hedwigia ciliata var. leucophaea new to England and Wales (the first British records for over 100 years)

Des A. Callaghan

51 Bishopdale Drive) Rainhil� Presco!y Mersryside) L3 5 4ffi·Descal l@ bluryonder.co.uk

Introduction from the Channel Islands to the Shetlands and throughout Ireland, but is absent from much of Until relatively recently Hedwigia ciliata was eastern and southern England. H. ciliata was thought to be a species easily recognised and much scarcer amongst the material studied by free from taxonomic uncertainty. However, Crundwell (1995), although it was also Hedenas (1994) showed that in Sweden and widespread. H. ciliata was subsequently included Fennoscandia this taxon comprised two in the British Red Data Book as 'Data Deficient' species: H. ciliata and H. stellata. The former was (Church et al., 2001), pending a better shown to occur throughout Sweden, whereas understanding of its distribution and trends in the latter had a very marked southern population size. distribution. Hedenas (1994) found that H. ciliata contained a Subsequently, Crundwell (1995) examined variety in Fennoscandia worth taxonomic several hundred British specimens assigned to recognition, i.e. H. ciliata var. leucophaea. The H. ciliata and found that the vast majority were distinctive characters of H. ciliata var. ciliata H. stellata. He showed that H. stellata occurred compared to var. leucophaea were said to be: 8