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Meetings of the BBS - 1969

 

Annual Meeting 1969

Lyme Regis 9-16 April

The Annual Meeting (9-16 April) was held at Lyme Regis on the Dorset-Devon border. Excursions were made into Devon (v.-c. 3), Somerset (v.-c. 5) and Dorset (v.-c. 9). The weather was favourable, being neither too dry nor too wet; and the Saturday excursion was attended by twenty-seven people.

10 April. Members spent the day exploring the cliffs and landslip to the west of Lyme Regis (v.-c. 3). This area consists of several miles of chalky undercliff, with thorn-thickets, spontaneous ashwood, and a little grassland. Because of the length to be covered the party split into two, one group working near Pinhay and the other near Goat Island. The Pinhay contingent recorded Amblystegium varium, Fissidens bambergeri, Gymnostomum calcareum, Scorpiurium circinatum, Seligeria pusilla, Anthoceros husnotii and Cololejeunea minutissima. On Whitlands Cliff, an interesting find, which caused some speculation in the field, was a plant which from its leaves appeared to be Ditrichum subulatum. The area near Goat Island was more varied, and several other species were recorded: Barbula unguiculata var. cuspidata*, Bryum capillare var. torquescens, Eurhynchium schleicheri, Leptodon smithii, Phascum curvicollum, Pottia commutata, Weissia tortilis*, Marchesinia rnackaii and Porella laevigata.

[* new vice-county record]

11 April. In the morning the party visited Prior's Park Wood (v.-c. 5), an area of neglected coppice. The ground was for the most part damp and calcareous, with Cratoneuron commutatum conspicuous in the ditches. Typical coppice epiphytes such as Orthotrichum affine, O. striatum, Neckera pumila, Ulota crispa and Lejeunea ulicina were seen on hazel. All these species were encountered repeatedly during the meeting. Other plants seen were Heterocladium heteropterum var. flaccidum, Orthotrichum pulchellum, Plagiothecium latebricola, Zygodon conoideus and Lophocolea bidentata c.per. At lunch-time a drizzle developed and many members sheltered in an agreeable public house at the top of the hill. Suitably fortified, they emerged on to the wet heath of Widcombe Moor, recording Dicranum spurium*, Cephaloziella subdentata and Odontoschisma denudatum*. Then everybody scattered and filled in mapping cards for nearby squares. Tortella nitida was found on the wall of the church at Donyatt; Riccia warnstorfii, Dicranella staphylina* and Plagiothecium latebricola in some damp coppice near Chaffcombe; Zygodon conoideus and Amblystegium juratzkanum on Blagdon Hill; and Polytrichum aurantiacum and Scapania compacta near Culmhead.

12 April. A blustery morning was spent working the banks of the Otter Estuary near Budleigh Salterton (v.-c. 3). Species seen were Amblystegium kochii, Bryum donianum, B. sauteri, Desmatodon convolutus, Epipterygium tozeri, Eurhynchium megapolitanum, Funaria fascicularis, Leptodon smithii, Pottia heimii, P. wilsoni, P. crinita, Scleropodium tourretii and Tortula papillosa. On sandstone rocks there were fair quantities of a form of Tortula vahliana with immature fruit. Then the party moved inland to Woodbury Common where on wet heath they found Funaria obtusa, Cephalozia macrostachya, Cladopodiella francisci, Odontoschisma denudatum and Riccardia latifrons.

The Annual General Meeting was held at 8.30 p.m.

13 April. This was the free day, and many members took the opportunity to visit Portland (v.-c. 9). The species seen were much the same as for the BBS excursion in April 1952. New records were Amblystegium serpens var. salinum*, Bryum capillare var. torquescens, Pottia starkeana and Scleropodium tourretii, while Eurhynchium meridionale, Funaria muehlenbergii, Gymnostomum calcareum, Cephaloziella baumgartneri, Marchesinia mackaii and Southbya nigrella were refound in their old haunts. Another party visited Hooke Park (v.-c. 9) and the valleys below it. Hooke Park also was the scene of an excursion in 1953 and many of the same plants were found. New records were Bryum donianum, Pohlia lutescens*, Reboulia hemisphaerica and the small-bulbilled form of Bryum bicolor.

14 April. With reduced numbers the party visited Eggardon Hill (v.-c. 9), chalk grassland with an outcrop of calcareous grit on its western slope. On the outcrop grew Cinclidotus mucronatus (nowhere near water), Leptodon smithii, Seligeria pusilla, Scorpiurium circinatum and Trichostomum crispulum var. viridulum. Zygodon viridissimus var. stirtonii was found on a wall and Mnium seligeri* in a marshy field nearby. In the afternoon the party moved to Powerstock Common - derelict coppice with a variety of soils. Records included Amblystegium juratzkanum, Atrichum undulatum var. minus*, Plagiothecium ruthei, Ptychomitrium polyphyllum* (on slag by a railway), Weissia microstoma var. brachycarpa* and Nowellia curvifolia. A detachment then drove to Eype Mouth and found Aloina rigida*.

15 April. First stop was East Hill near Ottery St Mary (v.-c. 3), and the party split up to explore the gulleys running eastwards towards Sidbury. One section went into Core Copse and reported Atrichum crispum and Saccogyna viticulosa. The other section chose the shaded goyle above Lincombe Farm, where a small stream trickled among sandstone rocks. On these rocks grew Brachydontium trichodes, Dicranella rufescens, Campylostelium saxicola* and Lophocolea fragrans. One car load then went to Harpford Wood and recorded Epipterygium tozeri and Eurhynchium schleicheri. The remainder drove down to Weston Mouth, where in a recently sown pasture grew flat-leaved Weissias (W. crispa var. aciculata*, W. microstoma var. brachycarpa* ); but a half-hour's search revealed little else: Ephemerum serratum var. minutissimum, Dicranella staphylina* and Brachythecium mildeanum.

A glance at the foregoing lists will show that the neighbourhood of Lyme Regis is not remarkable for its bryophytes. Indeed, it must be one of the most 'average' areas on the south coast of England. A moderate rainfall (35 in.) is accompanied by soft rocks, small hills and a pocket-handkerchief landscape. The ancient woodland has been felled or reduced to coppice; and whereas there has recently been an increase in properly managed forest, this has resulted not so much in the restoration of former habitats as in the drainage of heaths and bogs. In these circumstances the organizer, Mrs Appleyard, was confronted with an unusually difficult task in planning the excursions. Undoubtedly she selected the best sites in the district, and members were able to see a fair selection of habitats in an area which is still free from atmospheric pollution. All who attended will wish to thank her warmly.

M. O. HILL

 

Summer Meeting 1969

Sedbergh, 23-30 September

The summer meeting was held at Sedbergh, Yorkshire, from 23 to 30 August for the purpose of working N.W. Yorkshire (v.-c. 65) and the eastern part of Westmorland (v.-c. 69). Although the area has been well worked in the past, and few new vice-county records could be expected, especially for Westmorland, there were many old records to be refound and in addition very little mapping had been previously carried out in the region. The thirty-four members who attended for all or part of the meeting were rewarded by magnificent weather on all but one day.

24 August. The morning was spent in the vicinity of Sunbiggin Tarn, v.-c. 69. In the highly calcareous mires and springs around the tarn grew Cinclidium stygium in abundance, Gymnostomum calcareum, Mnium pseudopunctatum c.fr., M. seligeri, M. affine, Drepanocladus revolvens var. intermedius, Moerckia flotoviana and Leiocolea badensis*. Nearby acid moorland yielded Polytrichum alpestre, Campylopus introflexus c.fr. and C. brevipilus. Some members investigated Tarn Sike west of Sunbiggin Tarn. Here calcareous flushes containing Leiocolea bantriensis, L. muelleri, Acrocladium sarmentosum, Orthothecium rufescens, Splachnum ampullaceum c.fr. and Amblyodon dealbatus c.fr., with Bryum alpinum and Grimmia stricta on stones, form a network amidst oligotrophic peat hummocks supporting species of undisturbed blanket bog, the most notable of which were Sphagnum fuscum c.fr. and Cephalozia loitlesbergeri c.per.

[* new vice-county record]

In the afternoon, Crosby Gill (v.-c. 69), a wooded valley cutting through Yoredale limestone, was visited. Interesting species found in and around the stream were Barbula spadicea c.fr., Mnium stellare, Neckera crispa c.fr., Hygrohypnum eugyrium, Hypnum lindbergii, Plagiochila spinulosa, Barbilophozia atlantica, Lejeunea lamacerina var. azorica and Cololejeunea calcarea. The woods were rich in corticolous species and Dicranum montanum, Ulota drummondii*, Tortula intermedia, Orthotrichum striatum, Nowellia curvifolia and Riccardia palmata were recorded. Several members called at Orton Scar but failed to refind Trichostomum crispulum var. nigroviride.

25 August. In brilliant sunshine members split up into several parties to explore Whernside but none were successful in refinding Aulacomnium turgidum and the presence of this species there today, far outside its normal British range, should now be regarded as very doubtful. One party, ascending the hill from the west (v.-c. 64), found Bryum capillare var. elegans, Splachnum sphaericum and Calypogeia trichomanis on the blanket bogs and peat hags overlying the millstone grit which forms the summit cap of the hill. Greensett Crags (v.-c. 64), the highest limestone outcrops, on the eastern slopes, were a richer hunting ground and interesting plants seen here included Encalypta rhabdocarpa, Trichostomum crispulum var. nigroviride*, Grimmia trichodon, Barbula ferruginascens, Seligeria doniana c.fr., S. pusilla c.fr., S. trifaria c.fr., Tortula subulata var. graeffii, Mnium orthorhynchum, Barbilophozia barbata and Riccia sorocarpa.

Another party explored Great Blake Beck Gill (v.-c. 65) on the eastern side of Whernside. The best finds here were Sphagnum teres, Dicranella crispa, Tetraphis browniana c.fr., Bryum klinggraeffii, Ulota phyllantha*, Plectocolea hyalina, Solenostoma sphaerocarpum, Scapania scandica and Lophozia obtusa. Those who visited Upper Deepdale and Blea Gill (v.-c. 65) were rewarded with Sphagnum girgensohnii, S. fimbriatum, Dicranodontium denudatum* and Tetraplodon mnioides on the blanket bog, and Sphagnum robustum, Plagiobryum zierii c.fr., Eucladium verticillatum, Orthotrichum rupestre and Plagiochila spinulosa in the gill itself.

Rhynchostegiella teesdalei c.fr., Barbula spadicea c.fr. and Fissidens rufulus c.fr. were found at the bottom of Deepdale (v.-c. 65) and Leskea polycarpa, Orthotrichum lyellii and Tortula subulata var. subinermis* by the river at Corn Close near Sedbergh (v.-c. 65). There are old Dentdale records for Habrodon perpusillus and Leucodon sciuroides, but neither of these plants was seen during the meeting and it is possible that they are now extinct.

26 August. The gills cutting through Yoredale limestone, shales and sandstones on the Mallerstang area (v.-c.s 65 and 69) were visited. The richest of these proved to be Aisgill (v.-c. 69) where the most outstanding find was Leiocolea heterocolpos*. Other interesting species were Pohlia elongata c.fr., Bartramia hallerana c.fr., Plagiopus oederi, M. marginatum c.fr., Breutelia chrysocoma c.fr., Seligeria acutifolia var. longiseta, Tetraphis browniana c.fr., Tortula subulata var. graeffii, Orthothecium intricatum c.fr., Isothecium holtii, Plectocolea paroica, Saccogyna viticulosa and Solenostoma sphaerocarpum, whilst clay banks above the gill yielded Dicranella rufescens, D. crispa, Discelium nudum and Blasia pusilla.

At Hell Gill, the River Eden, demarcating the boundary between v.-c.s 65 and 69, descends through a spectacular vertical-sided gorge only a few feet across, whose walls were covered by almost pure carpets of Seligeria trifaria. Washer Gill nearby (v.-c. 65) yielded Porella cordaeana, Neckera crispa c.fr. and Mnium stellare. A separate party explored the valley of the R. Rawthey above Uldale House (v.-c. 65) and recorded Philonotis caespitosa *, Lepidozia trichoclados and Sphenolobus minutus*. Hypnum imponens was seen on Pudding Howe Hill (v.-c. 69).

Several members also looked at the R. Rawthey in Wandale (v.-c. 65), where Fissidens rufulus c.fr., Seligeria recurvata, Hygrohypnum eugyrium, Lophozia excisa*, Solenostoma sphaerocarpum and Marchantia polymorpha var. alpestris* (v-c.s 65 and 69) were noted. Woodland over the river in v.-c. 69 yielded Hypnum cupressiforme var. mamillatum c.fr., Fissidens celticus, Plagiothecium laetum c.fr. and Lejeunea ulicina.

27 August. Again in clear, sunny weather members ventured farther afield into the Lake District (v.-c. 69). One party explored the Naddle Forest to the east of Haweswater. Although many of the Atlantic species recorded from here were not seen, finds included Dicranum montanum, Cynodontium bruntonii c.fr., Orthotrichum tenellum c.fr., Hylocomium brevirostre, Sphagnum contortum, S. teres, Barbilophozia atlantica, Bazzania trilobata and Hygrobiella laxifolia.

Other members ascended High Street seeing Pterogonium gracile on rocks by Small Water on the way. The cliffs above Nan Bield yielded Andreaea alpina, Pohlia elongata, Bryum inclinatum c.fr., B. alpinum var. viride, Rhabdoweisia crenulata, Bartramia pomiformis var. crispa, Grimmia doniana, G. torquata, G. patens, Dicranum blyttii, Acrocladium sarmentosum, Plagiothecium denticulatum var. obtustfolium*, Gymnomitrion obtusum, Marsupella adusta and M. ustulata. Slightly more basic rocks were found on Mardale Ill Bell and Long Stile and additional species here included Amphidium lapponicum c.fr., Arctoa fulvella c.fr., Bryum capillare var. elegans, Grimmia funalis, Oedipodium griffithianum c.fr., Pohlia ludwigii, Rhacomitrium ellipticum c.fr., Trichostomum tenuirostre, Cephaloziella pearsonii, Gymnomitrion crenulatum, G. concinnatum, Marsupella alpina and Radula aquilegia. Archidium alternifolium c.fr., Bryum micro-erythrocarpum, Ditrichum cylindricum and Pellia neesiana were noted on the shores of Haweswater.

28 August was spent in the vicinity of Cautley Spout (v.-c. 65). Although well known bryologically, several new records were made for the area and many old ones confirmed. The bogs and wet pastures below the spout were rich in Sphagna and fifteen species, including S. girgensohnii, S. teres, S. warnstorfianum and S. contortum, were recorded. The environs of the spout were a rich hunting ground, where members saw Seligeria recurvata c.fr., Brachydontium trichodes c.fr., Rhabdoweisia fugax c.fr., R. denticulata c.fr., Bartramia ithyphylla c.fr., Funaria obtusa c.fr., Oedipodium griffithianum, Fontinalis antipyretica var. gracilis, Hygroamblystegium tenax, Drepanocladus revolvens var. intermedius, D. vernicosus, Radula lindbergiana and Frullania fragilifolia. From the rocks and flushes above the spout Bryum weigelii, Acrocladium sarmentosum, Solenostoma cordifolium, Chiloscyphus pallescens, Calypogeia trichomanis and Pellia neesiana were recorded. Additional species seen on Cautley Crag itself included Grimmia doniana c.fr., Amphidium lapponicum c.fr., Trichostomum tenuirostre, Tortella densa, Marsupella ustulata, Barbilophozia barbata, Lepidozia pearsonii and Anastrepra orcadensis.

29 August. The last day was spent in Upper Swaledale, an area little known bryologically. In the Rigg Beck Ravine (v.-c. 69) interesting species noted were Discelium nudum, Trichostomum brachydontium var. cophocarpum, Mnium orthorhynchum, Entodon concinnus and Thuidium philibertii. Bryum pallescens c.fr. and Weissia controversa var. densifolia c.fr. were seen on lead mine waste by the R. Swale (v.-c. 65) and Barbula trifaria c.fr., B. vinealis, Campylium calcareum c.fr., Zygodon viridissimus and Frullania fragilifolia at Kisdon Force.

Another party spent the day in Fossdale (v.-c. 65) and recorded Seligeria trifaria c.fr., Eucladium verticillatum, Barbilophozia barbata, Calypogeia trichomanis, Plectocolea hyalina, Ptilidium pulcherrimum and Pedinophyllum interruptum. Members who called at Twistleton Glen, Ingleton (v.-c. 64); to see Homomallium incurvatum also recorded Hypnum callichroum*.

Although the number of new vice-county records made on the meeting was rather small, many old records were confirmed and the lists made in twelve 10 km. grid squares were a valuable contribution to the mapping scheme. Grateful thanks are due to the land-owners who freely gave us permission to visit their properties, and to the many members who sent in mapping cards and lists of their finds.

JEFFREY G. DUCKETT
MARY DALBY

 

Autumn Meeting 1969

Birmingham, 25-26 October

A week-end meeting was held on 25-26 October in the Department of Biological Sciences, University of Aston in Birmingham, by kind permission of Professor A. J. Matty. The President, Mr J. H. G. Peterken, took the chair on Saturday, and the following papers were read, summaries of which are given below.

Mr T. J. BINES: 'Aspects of growth and nutrition of Ulota crispa.'

Ulota crispa (Hedw.) Brid. was found to be limited in its colonization to rugosities in bark. An accumulation of water was detected at these points using a dye technique. On examination of these sites on bark of Corylus avellana, Sorbus aucuparia and Quercus sp. there was no detectable difference in major cation content between these sites and the plain bark. The growth rate of cushions in relation to the twig diameter was measured. A positive correlation was obtained between the log. of twig diameter and the age of the cushion. It was found that the nutrient content of small cushions was high. This corresponded to a period of rapid increase in length and width but not in height. After this rapid increase the nutrient level of the cushion remained constant on a µg./g. dry wt. basis. Cushions do not therefore accumulate nutrients with age but maintain the same level after the initial growth increase, at least until they are colonized by other species. Further analyses of bark nutrient contents have been carried out. An interesting correlation was obtained between the potassium and magnesium levels (+ve) and the phosphate and iron levels (-ve). This probably indicates dust contamination of the bark surface. Leaching rates from the bark surface and Ulota crispa cushions were assessed. Little loss of the major cation occurred from the moss but measurable amounts, providing a weak nutrient solution for growth of epiphytes, were leached from bark.

Mr W. J. SYRATT: 'The effect of sulphur dioxide on epiphytic bryophytes.'

A continuous flow capillary dilution and humidifying assembly has been employed to investigate the effects of low concentrations of SO2 (down to 1 p.p.m.) at known humidities on chlorophyll breakdown, respiration rate and sulphate accumulation in seven epiphytic bryophytes. Results have shown that chlorophyll degradation is dependent both on the concentration and humidity at which the gas is supplied, the higher the humidity the greater the breakdown. Dicranoweisia cirrata had least breakdown. The SO2 tolerant moss D. cirrata was shown to be capable of converting SO2 to SO4¯ with a higher efficiency than the other species investigated and that this capability is light-dependent. Metzgeria furcata, a tolerant liverwort, though capable of large sulphate accumulations, was shown not to be more efficient than other more sensitive species. The more sensitive species converted only small amounts of SO2 to SO4¯. The fact that D. cirrata accumulates SO4¯ in the field has been demonstrated by means of a 160 km. transect north-east from London. As the distance from London increased (and hence SO2 pollution decreased) so the extractable sulphate in the moss decreased. The use of epiphytic bryophytes as indicators of air pollution, based on the sensitivity of the species investigated experimentally using fumigations with SO2 and on their observed field distribution, was considered possible. A range of tolerances and/or sensitivities was found in the species investigated, D. cirrata being most tolerant and Ulota crispa being most sensitive.

Dr P. J. GRUBB: 'The growth of the sporophyte of Polytrichum formosum Hedw.'

Whereas Haberlandt's early work on sporophyte growth suggested an emerging independence from the gametophyte, Rastorfer's studies suggested a continuing strong dependence for photosynthate. Experiments on defoliation and covering of the gametophyte in Polytrichum supported Rastorfer's view. So did experiments on the growth of isolated sporophytes - they develop a great deal but their dry weight decreases. Recent studies by Paolillo and Bazzaz confirm a real difference in this respect between Funaria (Haberlandt's plant) and Polytrichum (Grubb's and Rastorfer's). Covering the sporophyte of Polytrichum at various stages discloses a morphogenetic requirement for light. Long exposures are needed for normal development. Red light is most effective. Infra-red light does not reverse the red effect. The sources of the organic supplies to the sporophyte seem to vary: at least sometimes net redistribution from older organs is important as well as current photosynthesis in the gametophyte leaves.

Dr M. C. F. PROCTOR and Mr H. M. HINSHIRI. 'Some experiments on assimilation by bryophytes following desiccation.'

After a period of desiccation bryophytes regain their normal rate of net assimilation only after an 'activation period'. In experiments with Anomodon viticulosus, Porella platyphylla and other species, using a Warburg apparatus, it was shown that this effect is due to enhanced respiration, more or less proportionate to the duration and intensity of the preceding desiccation. There were also indications of increased sensitivity to stimulation of respiration by handling during recovery from desiccation. For moderate periods of desiccation there is apparently little effect on the photosynthetic mechanism, though there are indications that this is affected by prolonged desiccation. The conclusions agree broadly with those of Willis (with Tortula ruraliformis) and Ensgraber (with Conocephalum conicum), but the respiration peaks were of shorter duration, comparable in length with the 'activation periods' indicated for Hylocomium splendens by Stålfelt.

Dr R. S. CLYMO: 'The growth of Sphagnum.'

The substance of this paper is to be published in the Journal of Ecology, vol. 58, 1970.

Mr K. LEWIS: 'Experimental taxonomy of the bulbilliferous Pohlia.'

The bulbilliferous Pohlia are characterized by the production of bulbils or gemmae in the axils of their leaves. The bulbils differ both in form and in the number produced per leaf axil. These differences have been used as diagnostic features to delimit the taxa within the group. However, many of the descriptions and illustrations of bulbils in the literature are ambiguous and misleading and have caused much misidentification. Further, there has been some speculation concerning the stability of the buibils, regarding both their form and number per axil. For these reasons, the nomenclature and taxonomy of the bulbilliferous Pohlia has become a confused issue. Samples of these plants, collected from all over the British Isles, have been subjected to culture under uniform environmental conditions and it has been possible to resolve the limits of variation within each taxon. The Census Catologue of British Mosses (Warburg, 1963) lists six bulbilliferous species, namely Pohlia annotina (including the var. decipiens), P. proligera, P. bulbifera, P. rothii, P. drummondii and P. gracilis. As a result of the present work, it is proposed to merge P. annotina, P. annotina var. decipiens and P. proligera in one taxon, and two new taxa will be created.

After discussion and questions to speakers, the President thanked all who had contributed and Dr R. E. Longton for arranging the programme of papers.

In the evening a conversazione was held at the University and the following exhibits were displayed :
Mr T. LAFLIN: Bryophyte flora of Warwickshire.
Dr M. E. NEWTON: Sex chromosomes in bryophytes.
Mr M. V. FLETCHER: Some bryophytes from Skye.
Dr J. G. HUGHES: Aspects of growth in Phascum cuspidatum.
Mr E. C. WALLACE: Portraits of bryologists.
Mr K. LEWIS: Bulbilliferous Pohlia.

About twenty-five members, including the President, met on Sunday morning at Banners Gate, Sutton Park (v.-c. 38). The party walked first to Long Moor Mill Pool, where Pellia neesiana* and Mnium rugicum* were found. A number of uncommon Warwickshire bryophytes were refound in the boggy areas of Long Moor, including Splachnum ampullaceum, Mnium pseudopunctatum, Cratoneuron commutatum and its var. falcatum, Drepanocladus exannulatus, D. revolvens var. intermedius and Acrocladium giganteum.

[* new vice-county record]

On wet peat by a ditch near Rowton's Well Pohlia bulbifera* was found, confirming earlier gatherings, the identity of which had been doubted, from this place. Also on peaty ditch sides were Calypogeia muelleriana and Dicranella cerviculata. Members then moved on to Little Bracebridge bog and pool, where a number of interesting plants were refound. Among these were Leiocolea bantriensis, Scapania irrigua, Sphagnum plumulosum, Fissidens adianthoides, Mnium seligeri and Drepanocladus vernicosus. Mrs Appleyard discovered also Sphagnum teres, recorded by Bagnall in the nineteenth century from three places in Sutton Park, but recently found in v.-c. 38 only by Coleshill Pool. A picnic lunch was eaten in the Park, made enjoyable by the good weather.

A smaller number of people went on to the Alvecote Pools Nature Reserve, where they were received by Mr G. A. Arnold, the Warden. The reserve is on the site of a disused colliery, Subsidences have filled with water, forming large pools and boggy areas. Riccardia sinuata, R. pinguis, Lophocolea cuspidata and Dicranella cerviculata were found at the pool margins. Members were interested in the large slag heap which is erratically burning inside after spontaneous combustion. Where the burning comes near to the surface the heat kills the vegetation over areas of variable size, and the hot, bare ground is colonized by Pohlia nutans and Campylopus introflexus. Sulphur dioxide produced by the burning appears to have no ill effect on these two species. On bare wet ground at the base of the slag heap were Cephaloziella starkei, Lophozia bicrenata, Leptobryum pyriforme and the small-bulbilled form of Bryum bicolor. The party dispersed after thanking Mr Arnold for conducting them round the area.

J. G. HUGHES
T. LAFLIN

 

 
 
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