Heterodermia leucomela (L.)

Ciliate Strap-lichen PHYSCIACEAE SYN: Physcia leucomelos (L.) Mich. Anaptychia leucomelaena (L.) Massal.; Lichen leucomelos L. 1763

Status Nationally Rare UK BAP Priority Species Schedule 8 Wildlife and Countryside Act (1981) Lead Partner: Plantlife International RDB – Endangered (2003) 13/233 10km squares (9 in England, 4 in Wales) post 2000

UK Biodiversity Action Plan These are the current BAP targets following the 2001 Targets Review:

T1 - Maintain all known populations of this species. T2 - Increase the extent of existing populations where appropriate and biologically feasible.

Progress on targets as reported in the UKBAP 2002 reporting round can be viewed online at: http://www.ukbap.org.uk/2002OnlineReport/mainframe.htm

The full Action Plan for Heterodermia leucomela can be viewed on the following website: http://www.ukbap.org.uk/UKPlans.aspx?ID=363

Contents 1 Morphology, Identification, Taxonomy & Genetics...... 2 1.1 Morphology & Identification ...... 2 1.2 Taxonomic Considerations ...... 3 1.3 Genetic Implications ...... 3 2 Distribution & Current Status ...... 3 2.1 World ...... 3 2.2 Europe ...... 3 2.3 United Kingdom ...... 4 2.3.1 England ...... 4 2.3.2 Northern Ireland...... 4 2.3.3 Scotland...... 4 2.3.4 Wales ...... 4

Work on Heterodermia leucomela is supported by:

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3 Ecology & Life Cycle...... 6 3.1 Ecology ...... 6 3.2 Life Cycle...... 6 3.2.1 Dispersal...... 6 4 Habitat Requirements ...... 7 4.1 The Landscape Perspective...... 7 4.2 Communities & Vegetation ...... 7 4.3 Summary of Habitat Requirements ...... 11 5 Management Implications ...... 11 6 Threats / Factors Leading to Loss or Decline or Limiting Recovery...... 12 7 Current Conservation Measures ...... 12 7.1 In Situ Measures...... 12 7.2 Ex Situ Measures ...... 12 7.3 Research Data ...... 12 7.4 Monitoring Heterodermia Leucomela & The Common Monitoring Standard ...... 12 8 References ...... 13 9 Acknowledgements ...... 13

1 Morphology, Identification, Taxonomy & Genetics

1.1 MORPHOLOGY & IDENTIFICATION DESCRIPTION Heterodermia leucomela (Figures 1 & 2) is a distinctive lichen appearing fruticose and forming loose tufts up to 10cm across. The dichotomously branched, ivory-white thallus is between 3-5mm in width, with many black marginal cilia up to 5mm long. The lower surface is white and channeled, the central part arachnoid or powdery and variably sorediate. The lower cortex is not developed. Apothecia have not been observed in British material.

CHEMISTRY Medulla Pd+ yellow, K+ yellow-red, KC+ yellow–red, C– (zeorin and salazinic acid).

SIMILAR SPECIES This species can be confused superficially with several of the shrubby Cladonia species, but on close inspection cannot be confused with any other British lichen.

Figure 1 - Heterodermia leucomela (Drawing by Fred Rumsey).

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Figure 2 - Heterodermia leucomela growing on coastal rock with Teloschistes flavicans. (Photograph by Bryan Edwards).

1.2 TAXONOMIC CONSIDERATIONS Two subspecies are described; subsp. leucomela and subsp. boryi (Fée) Swinscow & Krog 1976.

1.3 GENETIC IMPLICATIONS None.

2 Distribution & Current Status

2.1 WORLD Heterodermia leucomela subsp. leucomela and subsp. boryi are both widespread in the tropics. Subsp. leucomela also extends to cooler regions, reaching the temperate zones (Swinscow & Krog, 1988).

2.2 EUROPE All records from Europe are from Atlantic and Mediterranean regions. There are old records from Sicily (1922), and Tuscany (1909), Italy (Nimis, 1993), Switzerland and north-east France (Moberg, 2004). Recent records are only known from Atlantic coast of France, particularly Brittany where it is found on coastal cliffs and in the crowns of forest 3 trees, and Spain and Portugal, including the Algarve (Jones, 1980). H. leucomela is widespread in the Macaronesian islands.

Most recent literature sources state that H. leucomela is ‘well established’ in south-west Ireland. This generally refers to Cork and Kerry from where there are a number of early literature records and herbarium specimens. However, there are very few post-1980 records, and its current status in Cork and Kerry is uncertain and in need of urgent review.

2.3 UNITED KINGDOM

2.3.1 ENGLAND In the 19th Century H. leucomela was distributed in scattered sites along the south coast of England from the Isles of Scilly east to West Sussex, with an outlying site on the Bathampton Downs, near Bristol. By 1950 it had undergone a significant decline and was recorded in the Isles of Scilly and Cornwall. Surveys in 2000 and 2001 found the species to be widespread and present in quantity on the Isles of Scilly and in three Cornish populations, the largest of which is on the west coast of The Lizard (see Figure 3 and Table 1) (Edwards, 2001, 2002).

2.3.2 NORTHERN IRELAND No confirmed records.

2.3.3 SCOTLAND No confirmed records.

2.3.4 WALES Historically H. leucomela was first recorded in Wales in 1895 by J.E. Griffiths who found it near Roscolyn on the west coast of Anglesey. In more recent times there are records from Bardsey and near Aberdaron on the Lleyn Peninsula. A survey in 2001 rediscovered the species on Anglesey and found healthy populations on the tip of the Lleyn Peninsula (Edwards, 2002). The Bardsey populations are part of a long term monitoring project. In 2004 the species was recorded for the first time in Pembrokeshire at St David’s Head, and in 2005 it was found in some quantity further south at Stackpole Head.

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Figure 3 – UK distribution of extant Heterodermia leucomela sites.

Table 1 - Summary of current Heterodermia leucomela sites in England and Wales. SITE GRID SITE STATUS DATE RECORDER POP’N Peninnis Head a SV90 SSSI Sep-01 Bryan Edwards 7 Peninnis Head b SV90 SSSI Sep-01 Bryan Edwards 50 Giant's Castle SV91 None Sep-01 Bryan Edwards 20 Deep Point SV91 None Sep-01 Bryan Edwards 12 Gap Point SV91 None Sep-01 Bryan Edwards 50 Hoe Point SV80 SSSI Sep-01 Bryan Edwards 70 Wingletang Down a SV80 SSSI Sep-01 Bryan Edwards 130 Wingletang Down b SV80 SSSI Sep-01 Bryan Edwards 50 Wingletang Down c SV80 SSSI Sep-01 Bryan Edwards 3 Castle Brose-Carnew Point SV80 None Sep-01 Bryan Edwards 45 Shipman Head Down a SV81 SSSI Sep-01 Bryan Edwards 35 Shipman Head Down b SV81 SSSI Sep-01 Bryan Edwards 70 5 SITE GRID SITE STATUS DATE RECORDER POP’N Shipman Head Down c SV81 SSSI Sep-01 Bryan Edwards 30 Popplestone Brow SV81 SSSI Sep-01 Bryan Edwards 100 Piper's Hole SV81 SSSI Sep-01 Bryan Edwards 90 Gimble Point - Gun Hill SV81 SSSI Sep-01 Bryan Edwards 400 St Martin's Head SV91 SSSI Sep-01 Bryan Edwards 40 Burnt Hill SV91 None Sep-01 Bryan Edwards 12 White Island, St Martins SV91 SSSI Jun-02 Bryan Edwards 146 Gwennap Head SW32 SSSI Sep-00 Bryan Edwards 60 Mullion Cliffs SW61 SSSI May-01 Bryan Edwards 30 Lower Predannack Cliff SW61 SSSI May-03 Bryan Edwards 18 Vellan Head SW61 SSSI May-02 Bryan Edwards 5 Gew Graze-Kynance Farm SW61 SSSI May-00 Bryan Edwards 80 The Horse SW61 SSSI May-00 Bryan Edwards 6 Rill Point SW61 SSSI May-03 Bryan Edwards 40 Kynance Cliff SW61 SSSI May-03 Bryan Edwards 15 Kynance north (EN) SW61 SSSI May-00 Bryan Edwards 260 Kynance north (NT) SW61 SSSI May-03 Bryan Edwards 40 Kynance south SW61 SSSI May-00 Bryan Edwards 125 Holestrow Cliff SW61 SSSI May-00 Bryan Edwards 24 Treleaver-Chynhalls Cliff SW71 SSSI Nov-00 Bryan Edwards 8 Pentire Head SW98 SSSI May-00 Bryan Edwards 6 Boconnoc Park SX16 SSSI Mar-04 Bryan Edwards 60 St David’s Head SM72 SSSI 2004 Tim Wilkins ? British Lichen Stackpole Head SR99 SSSI Apr-05 ? Society St Mary's Well, Aberdaron SH12 SSSI Jun-02 Bryan Edwards 18 Mynydd y Gwyddel, Aberdaron SH12 SSSI Jun-02 Bryan Edwards 12 Trwyn y Gwyddel, Aberdaron SH12 SSSI Jun-02 Bryan Edwards 85 Bardsey Island SH12 SSSI May-02 Tony Fletcher Penrhyn Mawr, SH27 SSSI Jun-02 Bryan Edwards 35 Penrhosfeilw Common Rhoscolyn Head SH27 None Jun-02 Bryan Edwards 5

3 Ecology & Life Cycle

3.1 ECOLOGY In the British Isles, H. leucomela is mainly a terricolous or saxicolous species. Historically there are several records from the crowns of ancient woodlands and parklands, and one current site is from tree branches. All current sites are in areas relatively free of SO2 pollution and are probably low in NO2. Given its past and present distribution, H. leucomela can be described as having a southern-oceanic distribution.

3.2 LIFE CYCLE

3.2.1 DISPERSAL H. leucomela has not been found fertile in the British Isles. The species is capable of vegetative reproduction as soralia are present along the underside of the thallus lobes. The soredia may be spread by invertebrates such as slugs. Alternatively, individual plants may be spread in very exposed sites by the wind, blowing plants around until they become anchored by the long black cilia.

6 4 Habitat Requirements

4.1 THE LANDSCAPE PERSPECTIVE All but one sites of H. leucomela is found on maritime cliffs, slopes and heaths. In these habitats H. leucomela is found growing among crustose, foliose and fruticose and bryophytes on thin soils and low boulders. The geology is varied with granite (Isles of Scilly), serpentine (The Lizard) and basalt (Pentire Head), but all sites are subject to salt spray. H. leucomela can also be found in woodland and parkland.

4.2 COMMUNITIES & VEGETATION COASTAL Within the National Vegetation Classification (Rodwell, 1991, 2000), H. leucomela is found in several coastal grassland and maritime cliff communities (Table 2). These communities are typically species-rich and open in nature with bare soil, small boulders and a number of terricolous bryophytes and lichens.

Table 2 - Summary of vegetation in which H. leucomela has been found. NVC COMMUNITY/SUB-COMMUNITY LOCATION CODE Isles of Scilly Land’s End H7 Calluna vulgaris-Scilla verna heath (Figure 5) Lleyn Peninsula The Lizard Armeria maritima-Cerastium diffusum cliff therophyte Anglesey MC5c community, Aira praecox sub-community (Figure 8) Isles of Scilly Festuca rubra-Armeria maritima grassland, Plantago Isles of Scilly MC8e coronopus sub-community (Figure 6) Lleyn Peninsula Anglesey MC10 Festuca rubra-Holcus lanatus grassland Pentire Head

H. leucomela is also found on boulders and rock outcrops within H6 Erica vagans-Ulex europaeus heath on The Lizard, and one of the core populations on The Lizard is on a serpentine scree with open W22 Prunus spinosa-Rubus fruticosus scrub. At a finer level, when growing on or near boulders H. leucomela is part of the Ramalinetum scopularis lichen community of the xeric-supralittoral zone. Characteristic associated species include Anaptychia runcinata (Figure 7), Ochrolechia parella, Parmotrema chinense, Ramalina siliquosa and Xanthoria parietina, plus the leafy liverwort Frullania tamarisci (Figure 7). Other uncommon or rare western species may be associated with H. leucomela including Cladonia firma and Heterodermia japonica (Figure 8), Parmotrema crinitum, Pseudocyphellaria aurata and Teloschistes flavicans.

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Figure 5 - Habitat for H. leucomela on The Lizard. H7 Calluna vulgaris-Scilla verna maritime heath broken by low serpentine boulders. Kynance Cove, May 2000 (Photograph by Bryan Edwards).

Figure 6 - Habitat for H. leucomela on The Lleyn Peninsula. Short MC8e Festuca rubra-Armeria maritima grassland, Plantago coronopus sub- community, broken by low boulders. St Mary’s Well, looking towards Bardsey Island, June 2002 (Photograph by Bryan Edwards).

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Figure 7 - Heterodermia leucomela with Anaptychia runcinata, Frullania tamarisci and Xanthoria ectaneoides on serpentine low serpentine boulder, Lower Predannack Cliffs, The Lizard, May 2003 (Photograph by Bryan Edwards).

Figure 8 - Heterodermia leucomela (centre top) in typical terricolous habitat in open maritime turf, MC5c/MC8e, with Cladonia firma, C. rangiformis, Heterodermia japonica, Lotus corniculatus and Plantago coronopus, Old Shipman Head, Bryher, Isles of Scilly, September 2001 (Photograph by Bryan Edwards).

9 WOODLAND & PARKLAND H. leucomela occurs very rarely as an epiphyte in Britain. Of the herbarium specimens examined only one collection was from trees. It was collected, with Heterodermia japonica, from Beech twigs in St Leonard’s Forest, West Sussex in 1892. In 2002 a new population of H. leucomela was discovered at Boconnoc, near Lostwithiel, Cornwall. The plants were also found on Beech twigs (Figures 8 and 9) with H. japonica. Other associates include common foliose and fruticose lichens such as Flavoparmelia caperata, Hypogymnia tubulosa, Hypotrachyna revoluta, Parmotrema chinense and Usnea cornuta.

H. leucomela is found as an epiphyte on old Beech and Oak in ancient woodland in western Brittany, France and on shrubs in the Algarve, Portugal. It occurs widely as an epiphyte in the tropics and sub-tropics.

Figure 9 - Open grown mature Beech tree supporting H. leucomela on well-lit twigs (Photograph by Bryan Edwards).

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Figure 10 – H. leucomela on well-lit Beech twig with Hypotrachyna revoluta (Photograph by Bryan Edwards).

4.3 SUMMARY OF HABITAT REQUIREMENTS From field surveys, the main factors influencing the distribution of H. leucomela are a warm oceanic climate, a predominantly southerly or westerly aspect and open, short maritime turf with scattered rocks maintained by grazing, exposure or naturally slow succession.

5 Management Implications Of the 40 populations that are currently known, only 13 are under any sort of formal management. H. leucomela is just one of many species that has suffered due to the cessation of grazing on cliff tops and coastal grassland and heath land sites. On The Lizard, 7 of the 12 sites have cattle or pony grazing. The site at Pentire Head is grazed by sheep as is one of the populations on Anglesey and the sites on Bardsey and the Lleyn Peninsula. On The Lizard, several important colonies on Lizard Downs National Nature Reserve were threatened by scrub encroachment and the associated fire risk. The scrub has been cleared from around the low rock outcrops and subsequent grazing is keeping the scrub in check.

On many of the remaining sites with no formal management the populations appear to be under no immediate threat. The sites on the Isles of Scilly, at Gwennap Head, Land’s End and Penrhosfeilw Common on Anglesey are within coastal grassland or heath land sites that are very exposed and the vegetation is kept in check by a combination of exposure, summer parching and, in some cases, rabbit grazing. However, monitoring is desirable at these sites to show population dynamics and highlight any gross changes so that suitable management can be put in place if necessary.

11 6 Threats / Factors Leading to Loss or Decline or Limiting Recovery H. leucomela has been lost from a number of counties (Table 3). The reasons for this loss are unclear. Low-level atmospheric pollution is the most likely cause as other pollution sensitive species have similarly declined in lowland Britain. Habitat change may have been a contributory factor locally with the cessation of cliff top grazing resulting in the encroachment of coarse vegetation and scrub.

H. leucomela is an attractive species and there are numerous historical collections in national and local herbaria. While over-collection has not been a major factor in the species overall decline it may have had an impact locally, for example Ballard Down in Dorset, from where there are at least eight copious collections in national herbaria.

Table 2 - Last records of H. leucomela in other counties. VICE-COUNTY SITE GRID DATE LAST SEEN 3, South Devon Babbacombe SX86 <1889 4, North Devon Morthoe SS44 c1878 6, North Somerset Bathwick Downs ST76 <1917 9, Dorset Portland SY67 1915 Hb. BM 13, West Sussex St Leonard’s Forest TQ23 c1892, Hb. BM

Most populations of H. leucomela are not under any immediate threat, as the sites in which they occur are owned or managed by conservation bodies.

The main threat to the species is from the encroachment of coarse vegetation and scrub. Firstly the vegetation can shade out the slower growing lichens, and secondly an increase in scrub can heighten the fire risk. H. leucomela is particularly sensitive to fire unlike Cladonia lichens which have the ability to recolonise if the fire is not very severe.

7 Current Conservation Measures

7.1 IN SITU MEASURES At present, 36 of the 42 populations are found within Sites of Special Scientific Interest (Table 1), many of which receive further protection as candidate Special Areas of Conservation (cSAC). The majority of the sites are owned or managed by conservation bodies. Of the 19 populations in the Isles of Scilly, 17 are within ownership of the Duchy of Cornwall and the land is managed by the Isles of Scilly Wildlife Trust. The Lizard supports 12 populations, of which 7 are owned and managed by English Nature and the remaining 5 are on land owned and managed by the National Trust. The three sites on the Lleyn Peninsula are all within ownership of the National Trust. Firebreaks have been put around some of the more important rock outcrops.

7.2 EX SITU MEASURES None.

7.3 RESEARCH DATA None.

7.4 MONITORING HETERODERMIA LEUCOMELA & THE COMMON MONITORING STANDARD None.

12 8 References Church, J.M., Coppins, B.J., Gilbert, O.L., James, P.W. & Stewart, N.F. (1996). Red Data Books of Britain and Ireland: Lichens Volume 1: Britain. Joint Nature Conservation Committee, Peterborough. Coppins, B.J. (1971). Field Meeting in Brittany. Lichenologist 5: 149-174 Edwards, B. (2001). The current status of Heterodermia leucomelos in Cornwall. Back from the Brink Report no. 159. Plantlife, London. Edwards, B. (2002). The current status of Heterodermia leucomela on the Isles of Scilly. Back from the Brink Report no.193. Plantlife, London. Edwards, B. (2002). The current status of Heterodermia leucomela in Wales. Back from the Brink Report no. 217. Plantlife, London. James, P.W., Hawksworth, D.L. & Rose, F. (1977). Lichen Communities in the British Isles: A Preliminary Conspectus. In Lichen Ecology, 295-413. Academic Press, London. Jones, M.P. (1980). Epiphytic macrolichens of the Algarve, Portugal. Lichenologist 12 (3): 253-276. Moberg, R. (2004). The lichen genus Heterodermia in Europe and the Macaronesian Islands. In: Contributions to Lichenology: Festschrift in honour of Hannes Hertel. P. Dobbeler & G. Rambold (eds): Bibliotheca Lichenologica 88. J. Cramer in der Gebruder Borntraeger Verlagsbuchhandlung, Berlin, Stuttgart. Nimis, P.L. (1993). The Lichens of Italy: An annotated catalogue. Museo Regionale di Scienze Naturale, Torino. Purvis, O.W., Coppins, B.J., Hawksworth, D.L., James, P.W. & Moore, D.M. (1992). The Lichen Flora of Great Britain and Ireland. Natural History Museum, London. Rodwell, J.S. (ed). (1991). British Plant Communities, Vol 2: Mires and Heaths. Cambridge University Press, Cambridge. Rodwell, J.S. (ed). (2000). British Plant Communities, Vol 5: Maritime communities and vegetation of open habitats. Cambridge University Press, Cambridge. Swinscow, T.D.V. & Krog, H. (1988). The Macrolichens of East Africa. British Museum (Natural History), London. Woods, R.G. & Coppins, B.J. (2003). A Conservation Evaluation of British Lichens. British Lichen Society, London.

9 Acknowledgements Thanks to Bryan Edwards for his work on the draft of this dossier. Thanks also to Plantlife International Volunteer James Peat for his editorial work on this dossier.

10 Contacts Plantlife International The Wild Plant Conservation Charity 14 Rollestone Street or contact enquiries: Salisbury [email protected] Wiltshire SP1 1DX Tel: 01722 342730

11 Links ARKive species web page for Heterodermia leucomela: http://www.arkive.org/species/ARK/fungi/Heterodermia_leucomela/ British Lichen Society: http://www.thebls.org.uk/ 13

Plantlife International wishes to acknowledge the financial support of English Nature, Scottish Natural Heritage and the Countryside Council for Wales for the Back from the Brink (species recovery) programme.

A leaflet highlighting the importance of H. leucomela along with other cliff top grassland and heathland terricolous lichens has been produced by Plantlife International and is aimed at landowners, land managers and conservation bodies.

ISBN: 1 904749-20-8

Original draft by Bryan Edwards Edited by Plantlife International First draft dated June 2004 Last revised 17 February 2006

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