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Meetings of the BBS - 1968

 

Annual Meeting 1968

Ross-on-Wye 3-9 April

The Annual General and Field Meeting was held at Ross-on-Wye, Herefordshire, from 3-9 April and was attended by thirty-four members. Most of the planned excursions were in Herefordshire (v.-c. 36), with one day in the Forest of Dean, W. Gloucestershire (v.-c. 34), but most members also visited neighbouring counties. Although Herefordshire had been well worked in the past and few new vice-county records could be expected, a number of interesting plants were found. Almost no mapping had previously been carried out in the region so that the lists made during the week, in twenty of the 10 km. squares of the Ordnance Survey National Grid, were a valuable contribution to the mapping scheme.

4 April. Bright sunshine was particularly welcome as it soon melted most of the snow that had preceded our arrival at Ross. Members worked in small parties to explore the woods and valleys near Woolhope, south-east of Hereford (v.-c. 36). Areas visited included Haugh Wood, where Ptilidium pulcherrimum* and Bryum ruderale* were found, and The Plantation which produced Campylium calcareum; Funaria fascicularis and Weissia rutilans were seen in a field on Backbury Hill and Plagiothecium denticulatum* on the edge of the wood; Tortula papillosa, Orthodontium lineare*, Rhynchostegiella curviseta, Isopterygium depressum, Plagiothecium sylvaticum*, Reboulia hemisphaerica and Lejeunea ulicina* were seen on or near Cherry Hill; Pottia caespitosa was refound on Common Hill where Fissidens exilis, P. lanceolata, P. recta, Phascum curvicollum, Acaulon muticum, Barbula acuta and Cephaloziella stellulifera were also noted. Members met for lunch at Broadmoor Common, and then visited Caplar Wood, where Orthotrichum sprucei was refound on trees on the bank of the R. Wye. Other species seen included Tortula latifolia, Cinclidotus fontinaloides, Barbula nicholsonii, Grimmia alpicola var. rivularis, Scleropodium tourretii, Eurhynchium schleicheri and Marchesinia mackaii. Tortula subulata var. subinermis and Barbula spadicea were found on the river bank near Perrystone Court.

[* New v.-c. record ]

5 April. Members drove to the Black Mountains above the Olchon Valley on the western border of Herefordshire. Work was somewhat hampered by snow but the steep Old Red Sandstone slopes of Red and Black Darens (v.-c. 36) were explored. Plants seen included Barbula ferruginascens, Philonotis calcarea, Isopterygium pulchellum, Orthothecium intricatum, Preissia quadrata*, Leiocolea bantriensis, Barbilophozia floerkei*, B. barbata*, Tritomaria quinquedentata and Marchesinia mackaii. After lunch one party who went to Blaen Olchon at the head of the valley found Plagiobryum zieri, Hygrohypnum eugyrium*, H. ochraceum*, Leiocolea muelleri, Sphenolobus minutus*, Mylia taylori* and Scapania uliginosa*. Another party visited Cwm Coedycerrig, west of Llanvihangel-Crucorney (v.-c. 35), and recorded Orthodontium lineare, Thuidium recognitum*, Hygroamblystegium tenax, Plagiothecium curvifolium, Trichostomum sinuosum and Porella laevigata. Other members explored the Grwyne Fawr Valley (v.-c. 35 and 42), where plants seen included Seligeria recurvata and Leiocolea badensis.

6 April. Members explored the Forest of Dean (v.-c. 34) in small parties. On the heaths around the ponds near Hazel Hill, Dicranum bonjeanii, Cratoneuron commutatum var. falcatum and eight species of Sphagnum were seen; Encalypta vulgaris, Pottia lanceolata, Barbula hornschuchiana, Lophozia excisa and L. bicrenata were noted on shale tips near by, and Rhytidiadelphus squarrosus c.fr. was found in adjacent woodland. Cephaloziella stellulifera occurred on waste ground north of Ruspidge Halt, while in Sutton Bottom Fissidens minutulus var. minutulus, Tetraphis pellucida c.fr., Metzgeria fruticulosa and Porella platyphylla were recorded. Fissidens exilis and Campylopus introflexus were found on Bearse Common, and F. viridulus, Aloina aloides, Tortella tortuosa, Campylium protensum and Cololejeunea rossettiana were seen in quarries near by. Mnium stellare, Hylocomium brevirostre and Lejeunea ulicina were noted in woodlands near Wyegate Green. After meeting near Cannop for lunch, members gravitated westwards to richer ground in the Wye valley. Plants seen on the limestone crags of The Slaughter (v.-c. 34) included Scorpiurium circinatum, Metzgeria conjugata, M. pubescens, Solenostoma sphaerocarpoidea and Anomodon longifolius, but members were distressed to find that a large patch of this very rare plant had already been needlessly removed. Tortula latifolia, Cinclidotus fontinaloides, Orthotrichum rivulare and O. sprucei were noted on the river banks near Brockweir. In the ravine at Llandogo (v.-c. 35), Plectocolea paroica, Plagiochila spinulosa*, Lophocolea fragrans, Saccogyna viticulosa, Lejeunea patens*, Fissidens curnowii*, F. rivularis and Jubula hutchinsiae were recorded, the last two also being seen in the valley above Whitebrook. Bryum micro-erythrocarpum* was found on Huntsham Hill (v.-c. 36).

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

7 April. No excursions had been planned for Sunday but members visited a number of different areas. Those who explored the wooded slopes and valleys near Tintern (v.-c. 35) recorded Pohlia rothii*, Rhynchostegiella teesdalei, Isopterygium depressum, Metzgeria fruticulosa and Diplophyllum obtusifolium, while Encalypta streptocarpa c.fr., Gyroweisia tenuis and Brachythecium glareosum were seen in a roadside quarry south of Tintern. Plants noted in a wooded glen below Cwrt Gilbert, south-west of Brecon (v.-c. 42), included Fissidens curnowii, Dicranodontium denudatum and Grimmia alpicola var. rivularis. Polytrichum alpestre, Splachnum ampullaceum, Acrocladium stramineum, A. cordifolium, Marchantia polymorpha var. aquatica*, Odontoschisma sphagni* and seven species of Sphagnum were seen on Rhosgoch Common near Painscastle (v.-c. 43). On the bank of the R. Wye near Bredwardine (v.-c. 36), one party saw Orthotrichum rivulare, O. sprucei, Myrinia pulvinata and Porella pinnata*. Fissidens celticus* was found on a stream bank near Luxley, N. of Mitcheldean and Ptilidium pulcherrimum* on an oak in Newent Wood (both v.-c. 34). Riccia warnstorfii and R. glauca* were seen near Redmarley D'Abitot (v.-c. 37), where Sphaerocarpos michelii and S. texanus were refound; the latter was also seen, with Dicranella staphylina and Pleuridium subulatum, in a field near Phocle Green, north-east of Ross (v.-c. 36). Plagiothecium curvifolium* was located in Chase Wood near Ross, and at Sellack Tortula papillosa and Bryum donianum were recorded. Tortula stanfordensis* was found on the bank of the R. Wye near Hoarwithy and on the following day T. vahliana was discovered on the roadside here, and more T. stanfordensis on the river bank east of Bolstone.

8 April. Members explored the limestone south of Great Doward (v.-c. 36) but were disappointed not to see a number of the species previously recorded there. However, Fissidens minutulus var. tenuifolius*, Tortula marginata, Gymnostomum calcareum, Bryum radiculosum, Mnium marginatum, M. cuspidatum, Campylium protensum c.fr., C. calcareum, Isopterygium striatulum, Eurhynchium schleicheri, Rhytidium rugosum, Riccia warnstorfii and Solenostoma sphaerocarpodea were noted. In north-facing limestone quarries near Welsh Bicknor, luxuriant carpets of bryophytes included Ctenidium molluscum c.fr., Hylocomium splendens c.fr., Rhytidiadelphus triquetrus c.fr. and Plagiochila asplenioides c.per.

9 April. Members visited Cocksbrook Wood near Orcop (v.c. 36), which proved disappointing, but Ephemerum serratum var. minutissimum, Anthoceros laevis and Fossombronia pusilla were seen in adjacent fields. The rocks on Garvay Hill Common were only found by one small party who recorded Polytrichum nanum, Campylopus introflexus*, Encalypta vulgaris, Grimmia orbicularis and Pterogonium gracile. In the valley of the R. Monnow north-east of Skenfrith (v.c. 35), Fissidens crassipes, Dicranella staphylina, Rhynchostegiella teesdalei and Tortula stanfordensis* were found. The latter was also seen on both banks of the R. Wye below Whitebrook (v.-c. 35 and 34*). Broad Meend bog near Trelleck (v.-c. 35) has deteriorated since the surrounding heaths were drained and planted with conifers but it was included on the programme as it is almost the only lowland bog in the district. Dicranum bonjeanii, Lepidozia setacea, Calypogeia muellerana, Mylia anomala, Cephalozia bicuspidata var. lammersiana*, C. connivens, Odontoschisma sphagni and five species of Sphagnum were noted here.

Although few of the areas visited were rich bryologically, ninety-four species and varieties of hepatics and over 260 species and varieties of mosses were noted by members during the week, and thirty-three new vice-county records were made. Temperatures during the week were generally low but we were fortunate in having dry weather nearly every day and members worked late into the evenings, covering many areas not included on the programme. I am grateful to all those who took the trouble to send in mapping cards and lists of their finds during the week, and to the Forestry Commission and landowners who gave us permission to visit their properties.

JEAN A. PATON

 

Summer Meeting 1968 (1)

Isle of Skye, 17-23 August

The first week of the meeting was spent centred on Broadford, Isle of Skye, from 17 to 23 August. Sixteen members attended all or part of the excursions. After one of the finest summers on Skye for recent years the weather was disappointingly bad, and as a result several of the localities were visited by different groups on different days. It is thus impossible to present this account in any chronological sequence, but merely in terms of the areas visited.

The Isle of Skye (v.-c. 104) is remarkable for its wide range of solid geology, topography and climate, resulting in a flora, both vascular and cryptogamic, of contrasting geographical and ecological categories. The areas visited were chosen in an attempt to sample some aspects of the island's richness. The Sleat Peninsula is probably the most sheltered area of the island. There are several extensive birch-hazel woods and waterfall-ravines, both of which provide habitats for several Southern-Atlantic species growing near their known northern limits. The places visited and some of the species found are: Gillean Burn - wooded glen with Hygrohypnum eugyrium, Hylocomium umbratum, Sematophyllum novae-caesareae, Tetraphis browniana, Aphanolejeunea microscopica, Jubula hutchinsiae, Lepidozia pinnata and Lophocolea fragrans. Tokavaig - deep limestone ravine with Gymnostomum calcareum, Orthothecium intricatum, Cololejeunea calcarea, Leiocolea turbinata and Metzgeria hamata. Wooded sandstone gorges nearby yielded Fissidens celticus*, F: crassipes*, F. curnowii, Grimmia hartmanii, Rhabdoweisia crenulata, Trichostomum hibernicum, Frullania germana, Harpalejeunea ovata, Jubula hutchinsiae, Plagiochila tridenticulata and Radula aquilegia. Coast S.W. of Drumfearn - north-facing coastal rocks and wooded ravines with Dicranodontium uncinatum, Dicranum scottianum, Fissidens celticus, Hypnum cupressiforme var. mamillatum*, Neckera pumila, Ulota drummondii, Bazzania tricrenata, Drepanolejeunea hamatifolia, Herberta adunca, Lepidozia trichoclados*, Mylia cuneifolia and Tritomaria exsecta. Tarskavaig Bay - woods with Ulota vittata and Harpanthus scutatus. Aird of Sleat oatfield with Bryum rubens*, B. sauteri* and Pseudephemerum nitidum. Loch nan Dubhrachan - Fossombronia foveolata and Hygrobiella laxifolia.

[* New v.-c. record ]

The Kyleakin area to the east of Broadford is rather similar to the Sleat, except that there is ground over 2000 ft., but this was not visited during the meeting. A party examined some of the ravines on the north-west side of Beinn na Seamraig, and although the parent rock is Torridonian Sandstone, several basic patches were found, with Isopterygium pulchellum, Glyphomitrium daviesii, Pohlia elongata, Rhacomitrium ellipticum, Seligeria pusilla, Eremonotus myriocarpus, Plectocolea paroica* and Solenostoma sphaerocarpum. Sheltered areas within the gorges were productive with Dicranodontium uncinatum, Rhabdoweisia crenulata, R. denticulata, Colura calyptrifolia, Douinia ovata, Lepidozia pearsonii, L. trichoclados, Plagiochila carringtonii and P. tridenticulata. A disused quarry to the west of Kyleakin yielded Archidium alternifolium, Ephemerum serratum var. serratum*, Fossombronia incurva*, F. wondraczekii*, Haplomitrium hookeri*, and Riccardia incurvata*, growing with Anagallis minima, Gnaphalium uliginosum and Isolepis setacea. Peaty banks nearby supported Calypogeia neesiana var. neesiana*, Cephalozia bicuspidata var. lammersiana, and C. leucantha.

The gabbro of the Cuillin Hills, although attaining 3000 ft., is generally poor botanically and attentions were thus centred on the lower slopes and the coast between Glenbrittle and Ulfhart Point. Much of the ground is covered with Molinia-Calluna bog, with Campylopus atrovirens var. falcatus, C. schwarzii, C. shawii, Sphagnum imbricatum, S. molle and S. strictum. The ultra-basic peridotite outcrop of An Sguman yielded Glyphomitrium daviesii, Grimmia decipiens var. decipiens and var. robusta, G. ovalis, G. patens, Hedwigia integrifolia and Ulota hutchinsiae. In flushes below An Sguman Acrocladium trifarium was seen with Sphagnum contortum and S. warnstorfianum. The coast is deeply indented by impressive ravines, and the sea-cliffs support mixed birch-hazel-rowan scrub. Species of interest noted between An Leac and Ulfhart Point include Cephaloziella pearsonii, Marchesinia mackaii, Grimmia hartmanii, Hypnum callichroum, Orthotrichum striatum and Trichostomum hibernicum. The most interesting find in the Cuillin area was Bryum dixonii*, found in a rock crevice by Allt Coire Lagan, its fifth British locality.

Bla Bheinn contrasts with the other Cuillin Hills in its floristic richness, due to outcrops of north-facing metamorphosed limestone in Coire Uaigneach. It supports typical montane calcicoles such as Barbula ferruginascens, Bartramia hallerana, Isothecium myosuroides var. brachythecioides, Plagiopus oederi, Pohlia cruda, Orthothecium rufescens, Seligeria doniana and S. pusilla. More local species seen here include Dicranum starkei*, Anthelia juratzkana, Eremonotus myriocarpus, Herberta straminea, Mastigophora woodsii, Mylia cuneifolia (on rock), Scapania aequiloba*, S. ornithopodioides and Solenostoma oblongifolium*. Basic outcrops on An Stac and An Carnach were rewarding with the addition of Leiocolea heterocolpos*, Marsupella adusta, M. alpina, M. stableri and Plectocolea subelliptica*.

The spectacular basalt escarpment of the Trotternish Peninsula is the richest botanical ground on Skye. Two areas were visited, The Storr and The Quirang. They are rather similar and provide a wide range of habitats, with extensive outcrops of basalt, in parts strongly calcareous, of varying aspect and shelter, interesting block litters, gullies and montane grasslands. Much of the area is unstable, with impressive landslip features providing conditions of locally high humidity and shelter. Typical plants of both areas include Amphidium lapponicum, Antitrichia curtipendula, Encalypta ciliata, E. rhabdocarpa, Glyphomitrium daviesii, Grimmia decipiens var. robusta, G. funalis, G. stricta, G. torquata (including a form with long hair-points), Mnium marginatum, M. orthorhynchum, Orthotrichum rupestre, Pterogonium gracile, Seligeria recurvata, Cololejeunea calcarea, Harpalejeunea ovata, Herberta straminea and Reboulia hemisphaerica. Rarities recorded at both sites include Barbula icmadophila, Dicranoweissia crispula, Grimmia apocarpa var. homodictyon, Anthelia juratzkana*, Barbilophozia lycopodioides, Plectocolea subelliptica, Mastigophora woodsii, Scapania gymnostomophila *, and Solenostoma oblongifolium. Further species of interest noted only at The Storr include Anomobryum concinnatum, Entodon concinnus, Plagiothecium denticulatum var. obtusifolium, Pohlia polymorpha*, Pterygynandrum filiforme, Lophozia obtusa* and Porella cordeana, whilst The Quirang supports Pohlia rothii, Seligeria pusilla, Colura calyptrifolia, Frullania microphylla, Marsupella funckii and Porella thuja.

Much of the coastline of northern Skye is formed of spectacular sea-cliffs. Two areas were briefly examined. Rubha Hunish north of Duntulm has extensive north east facing block-litters forming an undercliff at Meall Tuath. The area is remarkable for the abundance of Myurium hebridarum growing under heather, between blocks and in gullies. Impressive hepatic mats with Anastrepta orcadensis, Bazzania tricrenata and Herberta adunca occur near sea-level. Additional species of interest include Campylopus polytrichoides, Cynodontium strumiferum, Cephaloziella hampeana* and Frullania microphylla.

The cliffs of Beararaig Bay consist of Jurassic limestones with overlying basalts. Species of interest on the limestones include Anomodon viticulosus, Dicranella subulata and Eucladium verticillatum, whilst on an artificial basalt cutting for pipes from a nearby dam, abundant Barbula icmadophila was noted.

During the meeting several short visits were made to other areas. These included Coille Gaireallach and Ben Suardal Durness limestone ravine and outcrops with Amblystegiella sprucei*, Antitrichia curtipendula on hazels, Campylium chrysophyllum*, Heterocladium heteropterum var. flaccidum* and Leiocolea badensis*; and Arnisort oatfield with Bryum riparium*.

Many interesting and unexpected records were made during the week, and I would like to thank members for persisting under such difficult weather and for providing lists of their finds.

H. J. B. BIRKS

 

Summer Meeting 1968 (2)

Dingwall, 25-30 August

The second week of the Summer meeting, from 25 to 30 August 1968, was based on Dingwall, Ross-shire, bryologically a little-known area of Scotland. The weather was fine, and nine members attended for the whole week, although four had to leave on the last day. Dingwall, at the head of the Cromarty Firth, is well placed for both interesting acid moine schist and Old Red Sandstone on higher ground, and basic dunes and Old Red Sandstone near the coast, both in Easter Ross (v.-c. 106). Only the last day's excursion into Sutherland (v.-c. 107) took us into another vice-county.

25 August. The party visited the Black Isle Peninsula to look in particular at Ethie Burn ravine. This was reached by crossing a field at the head of the valley, where Anthoceros husnotii*, Dicranella crispa and Ephemerum serratum var. minutissimum* were found. On descending a precipitous sandstone cliff, Pterygoneuron ovatum was refound in one of its old habitats, and Aloina rigida* was seen on less open ground. Desmatodon convolutus grew on ground bordering the beach. The ascent of the ravine yielded several interesting plants, such as Mnium affine* in a wooded area, Orthotrichum pulchellum on an elder, Metzgeria pubescens*, Cololejeunea calcarea, Gyroweisia tenuis, Hygrohypnum eugyrium and Plagiothecium curvifolium. A stop at a quarry near Drummarkie produced more Aloina rigida and Bryum creberrimum*, and a marsh at Newton of Ferintosh yielded Fossombronia wondraczekii*, Archidium alternifolium, Pseudephemerum nitidum*, and Hypnum lindbergii.

26 August. The ascent of Ben Wyvis was achieved by crossing recently afforested moorland which produced Sphagnum fuscum and Tetraplodon mnioides. Under an unyielding sun, one party scaled the steep west face of Wyvis, finding Moerckia flotoviana*, Calypogeia trichomanis, Scapania uliginosa and Bryum weigelii in flushes, the last two also found by the second party on a lower stream. On the east side of the summit ridge, Moerckia blyttii, Marsupella varians, M. sphacelata and Conostomum tetragonum were found on dry exposed ground, and associated with a late snow patch near the summit, Haplomitrium hookeri* c.fr., an interesting find at 3000 ft., Pleuroclada albescens, Nardia breidleri*, Polytrichum norvegicum c.fr., Arctoa fulvella, Dicranum starkei, Splachnum sphaericum, Philonotis seriata and Plagiothecium platyphyllum* were discovered. On rocks and flushes in the corrie farther down, Anthelia juratzkana, Lophozia opacifolia, Marsupella stableri*, M. alpina, M. adusta, Scapania umbrosa, S. paludosa, Sphagnum lindbergii and Isothecium myosuroides var. brachythecioides were seen, and Barbilophozia lycopodioides, Gymnomitrion corallioides*, Scapania ornithopodioides, Rhabdoweisia fugax, Dicranodontium asperulum and Hylocomium umbratum grew amongst boulder scree lower on the slope. Rocks by the loch at the bottom of the corrie yielded Grimmia torquata, G. hartmanii, G. patens, Rhacomitrium ellipticum and Pterygynandrum filiforme. Solenostoma oblongifolium*, Plectocolea subelliptica*, Nardia geoscyphus*, Cephalozia pleniceps*, Barbula ferruginascens, Bartramia pomiformis var. elongata, Orthothecium intricatum and Hypnum callichroum were found on the way back to the summit.

27 August. Legs suffering from Ben Wyvis were relieved by a fairly gentle day on the dunes north-east of Tain. Despite afforestation, the remaining highly calcareous dune slacks revealed many interesting plants. On the dunes were Tortula ruraliformis c.fr., Barbula reflexa, Tortella inclinata, Thuidium abietinum* and Entodon concinnus, whilst in the slacks were Riccardia incurvata*, Moerckia flotoviana, Fossombronia incurva*, Haplomitrium hookeri, Bryum knowltonii*, B. creberrimum, a member of the B. bicolor aggregate, Meesia uliginosa and Catoscopium nigritum*. Returning, one party stopped at a salt marsh near Summerton to find Campylium polyganum*, and the other party saw Campylopus introflexus* and Desmatodon convolutus by a raised beach at Rockfield, both on the peninsula east of Tain.

28 August. The day was again spent on the Wyvis range. The more energetic of the party headed for Allt nan Caorach, where a gorge through Old Red Sandstone yielded many interesting plants. Tetraphis browniana and Seligeria recurvata were found on rock and Leiocolea heterocolpos* was growing amongst Amphidium mougeotii. Other species seen included Calypogeia neesiana var. neesiana, Eremonotus myriocarpus, Plectocolea paroica*, Marsupella sprucei*, Harpanthus flotovianus and Dicranella grevilleana c.fr. On rocks in the river were two forms of Hygrohypnum ochraceum and at the side of the path was a small piece of Tetraplodon angustatus. In the fork of a tree Antitrichia curtipendula with abundant fruit was seen. A large number of male plants of Discelium nudum* was found on an exposed clay bank of Allt Coire Misirich, an extension of range from Ayrshire for this plant. Meall a Tuire, visited by other members of the party, yielded Frullania fragilifolia, Atrichum tenellum*, Polytrichum nanum, Pohlia bulbifera and Hypnum cupressiforme var. mamillatum*, whilst Catoscopium nigritum was found above Black Rock in Glen Glass. A search of Evanton salt marsh for Bryum salinum was unsuccessful, but Riccia glauca, R. sorocarpa, Fossombronia wondraczekii and Dicranella schreberana c.fr. were seen, and Tortula laevipila and T. papillosa were found on an elder by the sea near Ardullie Lodge.

29 August. The party stopped first by the roadside at Altnabreac on Loch Achilty. Orthotrichum striatum was found on a tree by the shore and Mnium affine grew well in a nearby marsh. The path was followed through the wood to Loch an Droma, and Orthotrichum striatum, O. stramineum and O. pulchellum were found on trees overhanging a stream, and Frullania tamarisci var. robusta* occurred on rocks near the path. Around Loch an Droma several finds were made: Fossombronia foveolata* was in some abundance on exposed margins of the loch bed, and on sandy soil at the edge of the loch were Plectocolea paroica, Odontoschisma elongatum*, not seen in Britain for many years, Scapania subalpina, S. scandica and Pohlia bulbifera*. Near the falls of Conon, below Loch Luichart, a little Cryptothallus mirabilis was discovered beneath Sphagnum recurvum and nearer Dingwall, Diplophyllum obtusifolium* was found on a roadside bank and Barbilophozia hatcheri on an overgrown rock in a nearby field.

30 August, the last day, was spent filling in a few gaps in the Sutherland lists. A brief search in the first stubble field over the county boundary produced Riccia sorocarpa*, Anthoceros husnotii*, A. laevis*, Pseudephemerum nitidum* and Pottia truncata*. The dunes north of Embo did not look promising, being very overgrown, but Lophozia excisa*, Scapania aspera*, Seligeria recurvata*, Encalypta rhabdocarpa*, Tortula intermedia*, Barbula reflexa*, Tortella fragilis*, Bryum pendulum*, Thuidium philibertii*, Campylium elodes* and Drepanocladus lycopodioides* were discovered. Farther north, in woods near Little Torboll, the party found Campylopus introflexus* and Plagiothecium curvifolium* on tree bases, Sphagnum teres in boggy ground, and on boulder clay rocks Leiocolea bantriensis, Saccogyna viticulosa*, Scapania degenii *, Lejeunea cavifolia, L. patens* and Frullania tamarisci var. robusta*.

A visit to Cononbridge produced Riccia warnstorfii* and R. glauca*. Mapping cards were marked in fourteen 10 km. grid squares. Despite the area being rather dull geologically, many interesting plants were found, the most outstanding being Leiocolea heterocolpos, Odontoschisma elongatum, Scapania degenii and Discelium nudum, all being considerable range extensions. It is to be hoped that this meeting encourages the B.B.S. to hold further excursions in the area, and to visit other equally inviting but unexplored areas of Scotland. Thanks are due to Miss Duncan for organizing a very successful meeting, and to the members attending whose energy and hard work led to such an enjoyable and fruitful meeting.

BRIAN J. O'SHEA

 

Autumn Meeting 1968

Cardiff, 26-27 October

A weekend meeting was held on 26-27 October in the Department of Botany, University College of South Wales and Monmouthshire, Cardiff, by kind permission of Professor G. F. Asprey. On the Saturday the President, Mr J. H. G. Peterken, F.L.S., took the chair, and the following papers were read, summaries of which are given below.

Dr O.L. GILBERT: 'Bryophytes and atmospheric pollution.'

For a long time botanists have been aware that many common bryophytes are absent from a large area of the Lower Tyne valley. A brief literature and herbarium survey has indicated that their decline has taken place over the last 130 years. A thorough investigation into the distribution of these plants has revealed that not all species are equally affected and that various environmental factors such as shelter, pH, availability of nutrients, growth form of species, seral stage of community, water relations of the habitat, etc., can act to considerably increase or alleviate the harmful influence. (Constantly wet, high pH sites produce maximum alleviation and allow the survival of sensitive species in the centre of Newcastle.) The harmful influence was rapidly identified as air pollution by means of transplant experiments, chemical analysis and visits to other parts of the country. The effect of grit, sulphur dioxide, smoke, fluorine, vehicle exhaust and metal particles were investigated and it is now certain that sulphur dioxide is the most harmful pollutant in the air over Tyneside. The toxic limit of Grimmia pulvinata growing on sandstone walls has been calculated and it is found to be absent from this habitat in areas where the annual average sulphur dioxide concentration exceeds ca. 45 µg./m.³. Experimental work to explain how sulphur dioxide toxicity can be modified by the environment has revealed that the degree of ionization of sulphurous acid greatly affects its toxicity and that in thalli exposed to low concentrations (ca. 250 µg./m.³.) of sulphur dioxide, chlorophyll levels are affected long before respiration starts to fall. This must not, however, be taken as evidence that chlorophyll is the first system in the plant to be disrupted, as certain fungi are nearly as sensitive as green plants.

Mr G. CLARKE: 'Growth studies in bryophytes.'

The net annual productivity of Pohlia wahlenbergii var. glacialis on the sub-Antarctic island of South Georgia was measured using a coring technique for sampling. The dry weight of the current season's growth gave a net annual productivity ranging from 479 to 849 g./m.²/year at different sites. The presence of running water at a site appeared to be correlated with the higher figures. Values for the Relative Growth Rate, obtained both in situ in the field and in pot culture experiments, were also greater at sites where running water was present. Measurements of the length of the current season's growth showed that during the second half of the season the rate of increase of stem length was less than that of the dry weight per unit area. It was found that the weight per unit area could be correlated with the length if the closeness of packing of the stems was taken into account. Length measurements at various sites on Disko Island, West Greenland, indicated net annual productivity values of 665 to 1517 g./m.²/ year. The average productivity of Pohlia on Disko (latitude 69° N.) is evidently greater than that on South Georgia (latitude 54° S.). This is borne out by experiments with flowering plant seedlings and can be correlated with climatological measurements.

Dr N. G. BAYFIELD: 'Polytrichum commune - a hardy perennial.'

Polytrichum commune is a perennial moss with potentially unlimited apical growth. The tussock habit can be maintained over long periods on the same site by a cycle of growth, collapse and regrowth. Individual shoots frequently continue growth through more than two complete cycles. Shoot density varies throughout the cycle with collapse usually taking place when the stems are both tall and relatively widely spaced. Wind-tunnel studies showed that risk of desiccation increased as density declined. Below a density of about 0·45 stems/cm.² desiccation risk increased very rapidly. This may explain field observations that stem elongation rates generally showed a decline with density. At low densities stems appeared to have little mutual shelter or support. Water conduction in this species was discussed and water-potential curves compared with those for species lacking a well-developed internal conduction system.

Dr J.G.HUGHES: 'Sexual and apogamous races of Phascum cuspidatum.'

Apogamous plants of P. cuspidatum may be obtained from seta-cuttings. They are green plants, at first protonemal then with erect radially symmetrical microphyllous shoots, becoming leafless above with a terminal cauline sporangium. The protonemata are of the caulonema type, resembling the grosschloronema of Tetraphis pellucida under some cultural conditions. The leafy shoot has short internodes and small leaves compared with the sexual plant. The leaves are squarrose. Rhizoids are rarely formed. Branching of the leafy shoot is sympodial. The terminal leafless stem may be much branched, with branches often in whorls. The leafless meristems have an apical cell with two cutting faces, in contrast with the tetrahedral apical cell of the typical sporogonium, and the two histogens (endothecium and amphithecium) are lacking in the apogamous plant. When sporangia are formed they lack the ring of five stomata found on the sporogonium. Both sexual and apogamous races are summer annuals. In the seasonal variation in leaf number there is evidence that the sexual plants are adapted in favour of late developers. In neither race is leaf number conditioned by light intensity. Only in the apogamous race was leaf number reduced in daylight by the use of coloured filters, especially red. The frequency of the vegetative development of sporangia in the apogamous plants was low in daylight. Reduction of leaf number under coloured filters was not accompanied by increased development of sporangia. In both races vegetative growth was prolonged in fluorescent light and this was due to its excessive blueness. Under yellow-filtered fluorescent light, the vegetative development of sporangia was much increased. Sexual reproduction was favoured by reduced light intensity and this was due to effects upon the mechanism of antheridial dehiscence and the frequency of fertilization. In a discussion of the low fertility of the apogamous plants of this and other species, it was proposed that the alternation of generations in mosses is based in part on a mechanism which ensures that neither sporophyte nor gametophyte alone can form sporangia.

Dr R.L.JEFFERIES: 'Ionic relations of Cephalozia connivens and Leiocolea turbinata.'

The movement of ions into these two liverworts has been examined in relation to the ionic conditions which exist in the habitats where these plants grow. An analysis of measurements of electrical potential differences which exist between plant cells and the external solutions together with estimates of the concentration of ions in the plants suggests that at low external concentrations (0·1 mM) of potassium this ion is pumped into the tissues of these plants. The influx of potassium into plants of both species is sensitive to the inhibitor C.C.C.P. (1 x 10-6 M) and is markedly influenced by the calcium concentration and the hydrogen ion concentration in the external solution. Maximum influx of potassium into plants of Cephalozia connivens occurs when the calcium concentration of the external solution is 0·1 mM and the pH is 4·0. These conditions are similar to those that exist in the habitat where this plant grows. Corresponding conditions for plants of Leiocolea turbinata are where the pH of the external solution is 4·0-8·0 and the calcium concentration is 3·0 m M. These results are in close agreement with field data from habitats in which this plant occurs.

Mr D. C. SIGEE: 'Some observations on the fine structure of Cryptothallus mirabilis.'

Electron-microscope observation of the fine structure of the apical cell and its surrounding cells revealed the presence of normal proplastids. In apical regions of the thallus well back from the apical cell, and in wall cells of the archegonia, the plastids showed no tendency towards chloroplast differentiation. It was considered that the fine structure of these plastids was consistent with the presence of carotenoids and the absence of chlorophyll in the organelles. Preliminary investigation of the egg cell indicated a stage in which the periphery of the cytoplasm was highly vacuolated, with large amounts of endoplasmic reticulum, and with discrete masses of ribosomes (resembling nucleoli). The egg cell has an additional (possibly fluid) inner wall layer, which contains particles and organelles derived from the cytoplasm, and which may serve to isolate the development of the egg cell from its surrounding (gametophyte) cells.

Dr J. H. DICKSON: 'Scanning reflexion electron microscopy of bryophyte spores with special reference to Polytrichum.'

The scanning reflexion electron microscope is an excellent tool for revealing the details of the sculpturing of bryophyte spores. Taxonomic potentialities were illustrated by reference to Polytrichum. In this genus every species examined thoroughly so far is determinable by spore characters.

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

In the evening a conversazione was held in the Botany Department's laboratories and a large number of exhibits were displayed and discussed:
Dr J. G. HUGHES: Sexual and apogamous races of Phascum cuspidatum.
Mr J. R. HAMPSON: Forestry Commission literature.
Mr J. DRANSFIELD: Some attractive Malesian mountain bryophytes.
Mrs H. BIRKS: Some interesting bryophytes from the Isle of Skye.
Dr J. H. DICKSON: A. Encalypta mutica Hagen from Post-glacial Worcestershire.
B. The world range of Cryptothallus mirabilis.
Mr D. C. SIGEE: Some electron micrographs of Cryptothallus mirabilis cells and archegonia.
Mr S. G. HARRISON: Some bryophyte collections in the Welsh National Museum of Wales, Cardiff.
Dr K. BENSON-EVANS and
Mrs M. C. BROUGH (Cardiff Naturalists' Society):
Maturation cycles of some mosses from Fforest Ganol, Glam.
Mr R. D. FITZGERALD: East European Bryophyte Floras.
Mrs E. CAMPBELL and
Dr K. BENSON-EVANS:
Comparative studies on the maturation cycles in Marchantia polymorpha from opposite banks of the outflow stream at Llanishen Reservoir, Glam.
Dr K. BENSON-EVANS: Some illustrations of the anatomy and cytology of Cryptothallus mirabilis.

On the Sunday a field excursion was held. In the morning a visit was made to Morlais Hill and Morlais Glen, an area of carboniferous limestone near Merthyr Tydfil, and bryologically one of the richest districts in the county. Unfortunately, heavy rain made field work difficult and the intended visit in the afternoon to the Pennant Sandstone scarp of Craig-y-Llyn had to be abandoned. About 100 species were found amongst which may be noted: Oligotrichum hercynicum, Diphyscium foliosum, Dichodontium pellucidum, Ditrichum heteromallum, Pottia heimii, Barbula hornschuchiana, Gymnostomum aeruginosum, Pohlia elongata, Bryum pallens, Thuidium philibertii, Campylium chrysophyllum, Cirriphyllum piliferum, C. crassinervium, Preissia quadrata, Riccia sorocarpa, Leiocolea badensis, Solenostoma triste, Cololejeunea calcarea and Frullania germana.

A. E. WADE
KATHRYN BENSON-EVANS

 

 
 
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