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Meetings of the BBS - 1960

 

Annual Meeting 1960

Oswestry 7-12 April

The Easter meeting of the Society was held at Oswestry in Shropshire, from 7 to 12 April. The centre was chosen to combine visits to the famous Shropshire Meres and Mosses with relatively easy access to Welsh Border country. Although the number of members present fluctuated throughout the week forty-three attended some part of the excursions.

7 April. The first excursion, in sunny weather, was to the limestone quarries and rocky outcrops of Llanymynech Hill, south-west of Oswestry. Mr Charles Sinker, Warden of Preston Montford Field Centre, gave the party much local information throughout the meeting, and on this occasion explained the niceties of the boundaries of v.c.'s 40 and 47. Many species characteristic of rock crevices were growing in the old quarries, including Seligeria doniana (47)*, S. calcarea, Tortula muralis var. rupestris, Fissidens viridulus (47)* and Funaria muehlenbergii (47)*. Madotheca platyphylla, Scapania aspera (47)*, Zygodon viridissimus var. stirtonii (40), Bryum erythrocarpum (47)*, Trichostomum crispulum (47)*, Mnium affine and M. stellare were also recorded. Examination of deeply shaded limestones revealed Marchesinia mackaii in some quantity, also Pedinophyllum interruptum (47)*. Other interesting species from members' lists feature Bryum canariense var. provinciale (47)*, Cephaloziella hampeana (40)*, Leiocolea mulleri (40 and 47)*, Lophozia excisa (47)* and Barbilophozia barbata (47)*. Collections of the bryophytes on soil produced Dicranella schreberiana c.fr., Ephemerum serratum var. minutissimum (40)*, and in broken limestone turf Ditrichum flexicaule var. densum (47) with Thuidium philibertii (47)*. Several bryophytes were fruiting abundantly on tree-shaded limestone boulders, including Camptothecium sericeum, C. lutescens and Rhytidiadelphus triquetrus.

8 April. A visit was made to two of the famous Mosses east of Oswestry, Whixall Moss and Wem Moss. The weather was cold with a little rain on this occasion. In the morning the party left the cars by the Shropshire Union Canal after crossing a fine specimen of a counterbalanced bridge, and walked on to Whixall Moss, bearing west past the isolated trees of Oaf's Orchard. Mr Sinker directed us to the famous locality for Dicranum bergeri, which we discovered has been damaged by fire, and only a small amount of material was in good condition. Odontoschisma denudatum (40)* and Mylia anomala were also found in the bog with many species of Sphagnum. Other species noted were Lepidozia setacea and Dicranella cerviculata from the peaty sides of drainage ditches. The party then drove to Wem Moss where lunch was taken. The bog proved rich in Sphagnum species including S. cuspidatum, S. fimbriatum, S. tenellum, S. compactum, S. subsecundum, S. plumulosum, S. papillosum, S. recurvum and the rare S. pulchrum. Amongst the Sphagna the liverworts Lepidozia setacea, Calypogeia sphagnicola (40)*, Odontoschisma denudatum (40)*, O. sphagni, and C. muelleriana (40)* were found.

On the way back to Oswestry the party called at White Mere, southeast of Ellesmere, but the lake margin proved most disappointing; continuing to Crose Mere, near the village of Kenwick, the water's edge was much less paper-strewn and several things of interest were found. Physcomitrium pyriforme was plentiful on soil in the field adjoining the Mere. Bryophytes of the vegetation at the water's edge included Eurhynchium speciosum, usually at the base of tussocks of Carex paniculata, Acrocladium cuspidatum c.fr., Amblystegium juratzkanum, Hygroamblystegium tenax and Leptodictyum riparium.

9 April. The third excursion was to Pennant Melangell near Llangynog west of Oswestry; the day was sunny and breezy. Some members collected in Nant Achlas, a valley west of Pennant Melangell; most, however, concentrated on the main Cwm. Along the wooded stream margins, below the falls in Blaen y Cwm, several interesting epiphytes were seen including Orthotrichum affine, O. lyellii, O. stramineum and O. striatum, all with capsules. Also present on the trees were Neckera pumila, Leucodon sciuroides, Tortula laevipila, Orthotrichum pulchellum (47)* and a single patch of Ptilidium pulcherrimum (47)*. After careful searching Tortula subulata var. subinermis (47)* was discovered on moist tree boles. On the rocks at the stream edge Hyocomium flagellare was collected, a species rare within the valley. Nowellia curvifolia (47)* occurred on dead wood.

Among the bryophytes of the rocky outcrops on the upper slopes were Oedipodium griffithianum c.fr. (47)*, Cynodontium bruntonii, Fissidens osmundoides, Seligeria recurvata (47)*, Oligotrichum hercynicum, Lepidozia pearsonii, Calypogeia neesiana var. neesiana (47)*, Polytrichum alpinum (47)* and Plagiobryum zierii. Interesting plants collected near the waterfall on wet east-facing rocks included Preissia quadrata (47)*, Hygrohypnum ochraceum, Ctenidium molluscum var. robustum, and Breutelia chrysocoma c.fr. On drier boulders abundant Antitrichia curtipendula was found and specimens of Grimmia hartmanii (47)*, and Trichostomum brachydontium var. littorale (47)*. Lophozia silvicola (47)*, L. alpestris (47)*, Riccardia multifida c.fr., R, sinuata (47)*, Calypogeia arguta, Lophozia incisa, L. floerkii and Tritomaria quinquedentata were also recorded from the upper rocky outcrops. Species from Nant Achlas valley include Funaria attenuata, from wet sandy banks, Ptilidium pulcherrimum on birch trees, and Anastrepta orcadensis (47)* growing on steep grassy slopes at 1200 ft. Also, on sandy banks, were patches of Dicranella subulata (47)* and another interesting find was Acrocladium sarmentosum (47)* in a marsh at 1250 ft.

The lists produced by members for the area indicate the rarity of Lejeunea spp. and the absence of such species as Plagiochila spinulosa.

10 April. No excursions were planned for Sunday, but several members visited Nant-y-ffrith and several new v.c. records were made. Orthodontium lineare (50)*, Cirriphyllum piliferum*, Ditrichum heteromallum*, Eurhynchium praelongum var. stokesii*, Isopterygium depressum* and Polytrichum commune*, all in v.c. 51.

11 April. In excellent weather Breidden hill, a dolerite mass south of Oswestry, was visited. Fine views of the Shropshire countryside were enjoyed as the party explored the north-facing slopes. Of particular interest was Bartramia stricta, a very restricted southern species, which was present in some quantity in the sterile state. Several patches of fruiting material were also seen. The vertical shaded basic rocks produced Targionia hypophylla, Fissidens pusillus (47)*, Frullania fragilifolia, Isopterygium depressum. On pockets of soil another southern species, Scleropodium illecebrum, was found by several members. Characteristic of the stones below the vertical faces of rock were Orthotrichum rupestre (47)*, and Philonotis capillaris. Mixed woodland occupies much of the intermediate slope of the north side of the hill, the upper part being open. Calcifuge plants such as Barbilophozia attenuata (47)* and Campylopus fragilis were present in the ground-flora; Metzgeria fruticulosa (47)* was epiphytic on deciduous trees. Several Grimmias were collected from exposed rocks, G. funalis (47)*, G. retracta (47)* being new v.c. records. Lophozia excisa is reported from soil covered rocks by one member, and also Campylopus subulatus from thin earth on open ledges.

Lophozia alpestris (40) and Ephemerum serratum var. minutissimum (40)* were recorded on Corndon Hill (V.C. 47) by several members, who, enjoying the afternoon sunshine, returned to Oswestry by a long detour. They also discovered Fissidens exilis (47)* near Trinity Well, Long Mountain, and Riccia fluitans (47)* in the Shropshire Union Canal north of Buttington. The canal bank proved interesting and Fissidens incurvus (47 )* and Bryum erythrocarpum (47)* appear in the collections.

12 April. The limestone area of west-facing cliffs known as Eglwyseg Rocks, near Llangollen, provided an interesting final day to the excursions. Unfortunately the weather was cold with a little rain. The bryophytes recorded from the limestone include Neckera crispa c.fr., Porella laevigata (50)*, P. cordeana, all in shaded places, Grimmia orbicularis, Trichostomum brachydontium var. cophocarpum on exposed boulders, and Barbula reflexa from limestone soil. Above the limestone cliffs amongst Calluna, Leptodontium flexifolium was found, and along the stream sides Orthothecium intricatum, Cratoneuron commutatum var. virescens (50)*, Aplozia riparia and Hypnum patientiae. The same area also produced Lophozia barbata and Blepharostoma trichophyllum (50)*. At the north end of the valley, World's End, several records of interest were made, including Weissia crispata, Barbula rigidula c.fr., and Riccardia palmata (50)*.

On the return journey to Oswestry several members stopped at the bank of the Dee near Chain Bridge and plants of interest reported in their lists include Amblystegium varium (50)*, Tortula subulata var. subinermis (50)* on waterside trees, Lejeunea cavifolia (50)*, and several Grimmias, G. commutata, G. retracta and G. trichophylla, on rocky outcrops.

On behalf of all the members who attended the meeting, I should like to thank Dr E. F. Warburg and Mr A. J. E. Smith for the excellent organization of both the accommodation and the excursions. Even though no plants of exceptional interest were seen, many members found and saw species new to them and all thoroughly enjoyed this skilfully planned Easter Meeting. Our thanks too go to Mr C. Sinker, Warden of Preston Montford Field Centre, whose knowledge of the Oswestry area proved so valuable to the Society.

DAVID BRIGGS

Autumn Meeting 1960

Ullapool, 27 August-10 September

The autumn meeting was held at Ullapool, Wester Ross, from 27 August to 10 September, and was attended by sixteen members. The Society had not met before in the north-western Highlands of Scotland, where indeed Ullapool is probably the only suitable place on the mainland with sufficient accommodation. Ullapool is within reach of a wide range of interesting ground, but time in the field was restricted both by the need to travel rather long distances over a notoriously bad road system and by the custom in Scottish guest-houses of serving high teas at an inconveniently early hour.

The first excursion was to the two eastern corries of An Teallach (v.c. 105), to the south-west of Ullapool, a mountain well known to climbers but unexplored bryologically. Unfortunately the party did not go the best way up, and work was also interfered with by heavy rain and low cloud. Members unfamiliar with them had their first introduction to the large hepatics so characteristic of the West Highland mountains: Pleurozia purpurea, Scapania ornithopodioides, S. nimbosa, Jamesoniella carringtonii, Mastigophora woodsii, Herberta hutchinsiae, H. adunca and Bazzania pearsonii. Other plants seen were Dicranella squarrosa in fruit, Dicranoweissia crispula, Dicranum fuscescens var. congestum, Dicranodontium uncinatum, D. asperulum, Mnium affine, Philonotis fontana var. tomentella*, P. seriata (down to 1750 feet alt.), Isothecium myosuroides var. brachythecioides, Plagiothecium denticulatum*, P. roeseanum* and Lepidozia pearsonii.

[* = New v.c. record]

The second mountain excursion was to that part of Ben Dearg which lies in Wester Ross (v.c. 105), at the head of Gleann na Sguaib. Tetraplodon angustatus was seen on the way up, Bryum muehlenbeckii in some quantity by a lochan at 2400 feet. On the rocks and in the scree above were Dicranoweissia crispula, Leptodontium recurvifolium Rhacomitrium micrcocarpon, Pohlia annotina*, Meesia uliginosa, Acrocladium trifarium, Isopterygium muellerianum, Harpanthus Flotovianus and scattered stems of Anastrophyllum joergensenii. Bad weather curtailed the excursion, and the area would be worth revisiting.

Two visits were paid to the Fannich Mountains. On the first the party left the road near the western end of Loch Droma and went via Loch a'Mhadaidh to the ridge connecting Sgùrr Mòr with Càrn na Criche, which forms the boundary between West and East Ross. On the route to the ridge, in v.c. 105, were seen Sphagnum warnstorfianum, S. fuscum in fruit, Tetraplodon angustatus, Plagiothecium denticulatum var. obtusifolium and Barbilophozia lycopodioides. Just within Wester Ross were Anthelia juratzkana*, Lophozia opacifolia* with perianths, and, on Càrn na Criche, Ditrichum zonatum var. scabrifolium*. There was a little Aulacomnium turgidum on both sides of the county boundary, and in v.c. 106 were Marsupella adusta*, Scapania scandica* and also Rhabdoweissia fugax at the unusually high altitude of 2850 feet. The few members who came back over the top of Sgùrr Mòr found the view rewarding but the bryophytes dull, though Aulacomnium turgidum was about in some quantity.

The second Fannich excursion was to Loch Li (v.c. 106), reached from near the eastern end of Loch Droma across a very wearisome stretch of moorland. The corrie in which the loch lies is not a beautiful one and the weather was indifferent, but the rocks, and screes to the north-west of the loch proved of considerable interest. The species found here included Dicranella subulata*, Barbula ferruginascens, Trichostomum hibernicum*, Leptodontium recurvifolium, Pseudoleskea patens, Isopterygium muellerianum, Plagiothecium denticulatum var. obtusifolium, Cephalozia bicuspidata var. lammersiana*, Lophozia obtusa*, Anastrophyllum joergensenii, Lepidozia pearsonii* and Lejeunea patens*. Tetraplodon angustatus was found on moorland near Loch Li, Bryum erythrocarpum* by the road.

The last mountain excursion was made by a small party in perfect weather to Ben Dearg, the ascent of the mountain being from the south-west, the descent by Choire Ghrànda and Loch Coire Làir, all in v.c.l06. The summit area and Choire Ghrànda had a rich bryophyte flora including Sphagnum teres*, S. fuscum*, Polytrichum norvegicum, Acrocladium trifarium, Hylocomium pyrenaicum*, Moerckia blyttii, Lophozia opacifolia*, Anastrophyllum joergensenii, Harpanthus flotovianus. Marsupella sphacelata*, M. adusta, M. ustulata, M. sprucei*, Calypogeia trichomanis*, Anthelia juratzkana* and Scapania paludosa. S. subalpina* was seen near Loch Coire Làir.

The Durness limestone occupied a good deal of the meeting's attention. The first visit was to the crags by the roadside to the south-west of Knochan. These are crossed by the county boundary. The small part of the area in Wester Ross yielded Encalypta ciliata*, Amblyodon dealbatus*, Thuidium recognitum*, Radula lindbergiana and Frullania germana. On the Sutherland side (v.c. 108) were Seligeria recurvata, Pseudoleskea catenulata var. acuminata, Cirriphyllum piliferum*, fruiting Orthothecium rufescens and Reboulia hemisphaerica*. At Elphin were Dicranella schreberiana*, fruiting Trichostomum brachydontium var. cophocarpum and Grimmia apocarpa var. homodictyon. Also seen in West Sutherland were Atrichum undulatum var. minus*, Hypnum hamulosum and Lejeunea patens*. The geological map shows limestone near Loch Urigill and some of the party went there in hope, but most of it is covered with drift. Cinclidium stygium was seen on the way. The birch wood by the loch is uninteresting, but had Hypnum cupressiforme var. mamillatum*.

Inchnadamph is botanically the best known locality on the Durness limestone and almost certainly the richest. A good many bryologists have collected there before, but a day's visit added a surprising number of new records for West Sutherland. Noteworthy species found on the cliffs to the south of the hotel included Tortula princeps, T. subulata var. graeffii*, Gyroweissia tenuis, Gymnostomum calcareum, fruiting Trichostomum brachydontium, Weissia rutilans*, Grimmia apocarpa var. homodictyon, Bryum mildeanum, Thuidium recognitum* and Solenostoma atrovirens var. sphaerocarpoidea*. Two plants of special interest, both growing luxuriantly, were Tortella inclinata var. densa (Lor.) Limpr. and Gymnostomum recurvirostrum var. insigne. Both have strong claims to be treated as species. The former has hitherto in the British literature gone under other names (Tortula tortuosa fo. curta, T. tortuosa var. rigida) but is quite distinct from both T. tortuosa and T. inclinata, though more closely related to the latter.

On the same day a few members visited the Traligill valley at Inchnadamph. The most interesting finds here were a polysetous form of Barbula spadicea, Gymnostomum recurvirostrum var. insigne, Orthotrichum cupulatum var. nudum, Ulota drummondii, U. vittata*, Cratoneuron commutatum var. virescens*, C. filicinum var. fallax*, Rhynchostegiella teesdalei* and Porella cordaeana*.

On another excursion to the West Sutherland limestone the party made a short stop at Ledbeg, which proved poor, and then visited the Allt nan Uamh, about three miles south of Inchnadamph. Hygrohypnum dilatatum was seen in the stream, quite close to the road. In or near the stream on the way to the caves were Seligeria doniana, Bryum mildeanum, Rhodobryum roseum*, Marchantia polymorpha var. alpestris* and Calypogeia trichomanis*. Amblystegium compactum was seen in the caves, Seligeria tristicha* and Pseudoleskea catenulata var. acuminata nearby. The crags above and to the west of the caves had a very little Encalypta alpina* and also Tortella inclinata var. densa, Grimmia trichodon* and Anomobryum concinnatum*.

The geological map showed the limestone outcropping around Loch Ailsh, an area to which no bryologist seems to have been before. A morning was spent on the limestone and overlying drift to the south-west of the loch in East Ross (v.c. 106), and resulted in a long list of new records: Fissidens cristatus*, Seligeria doniana*, Dicranella varia*, Barbula hornschuchiana*, B. reflexa*, Trichostomum brachydontium*, Leptodontium flexifolium*, Pohlia delicatula*, Mnium marginatum*, Ambloyodon dealbatus*, Thuidium philibertii*, Campylium chrysophyllum*, Drepanocladus revolvens var. intermedius*, Eurhynchium swartzii*, Leiocolea bantriensis*, Chiloscyphus pallescens*, Cephaloziella hampeana*, Calypogeia neesiana* and Frullania fragilifolia*. The afternoon was spent on the east side of the loch, in East Sutherland (v.c. 107). The Allt na Cailliche yielded Andreaea rothii*, Fissidens osmundoides*, Rhabdoweissia denticulata*, Dicranella crispa*, D. varia*, Barbula hornschuchiana*, B. fallax*, Pohlia albicans*, Bryum argenteum*, B. bicolor*, Orthothecium intricatum* and Pellia fabbroniana* : while by the loch and in the extensive limestone area near Bennore Lodge were Fissidens pusillus*, F. taxifolius*, Seligeria doniana*, Weissia rutilans*, Grimmia hartmanii*, Ephemerum serratum var. minutissimum*, Bryum mildeanum*, Mnium marginatum*, Philonotis calcarea*, Climacium dendroides*, Thuidium delicatulum*, T. recognitum*, Cratoneuron commutatum var. falcatum*, Drepanocladus revolvens var. intermedius*, Riccardia sinuata*, Plectocolea paroica* and Scapania aequiloba*.

A final visit to the Durness limestone was in the valley of the Ullapool River (v.c. 105). The limestone, which is being quarried here, had a fairly good calcicole flora with Fissidens viridulus*, Seligeria doniana*, Barbula hornschuchiana*, B. cylindrica*, Weissia microstoma*, W. rutlilans*, Grimmia apocarpa var. homodictyon, Mnium stellare*, Leucodon sciuroides* and Leiocolea badensis. Hypnum cupressiforme var. mamillatum was seen on a tree and Calypogeia sphagnicola*, Mnium seligeri* and Cladopodiella francisci on boggy ground off the limestone.

Several visits were paid to other habitats on the low ground. The first was to Doire Dhubh, a small birch wood bordering a loch on the north side of Cul Beag (v.c. 105). The mosses were perhaps a little disappointing, the only species of interest being Sphagnum quinquefarium, Glyphomitrium daviesii and Zygodon conoideus, but the liverworts more than made up. Calypogeia suecica*, found by Dr Warburg on a rotting log was the best. Other noteworthy species were Sphenolobus hellerianus*, Tritomaria exsecta*, Cephalozia catenulata*, Plagiochila tridenticulata, Harpalejeunea ovata, Aphanolejeunea microscopica, Frullania germana and a great abundance of Colura calyptrifolia.

One morning was spent on the dunes on the west side of Achnahaird Bay (v.c. 105). Bryum calophyllum*, mixed with a little B. warneum*, was abundant in several places, and in good condition though, as so often in Bryum populations, showing a good deal of capsule malformation. Other species seen here were Archidium alternifolium in fruit, Dichodontium pellucidum var. fagimontanum*, Barbula tophacea*, Mnium rugicum*, Moerckia flotoviana and Barbilophozia hatcheri. The afternoon was spent at Reiff Bay (also v.c. 105), where it was hoped that Myurium hebridarum or Campylopus shawii might be found. The ground was a little disappointing, but produced Pottia truncata*, P. intermedia*, Bryum bicolor*, Cephaloziella hampeana*, C. subdentata, Cephalozia bicuspidata var. lammersiana, Calypogeia trichomanis and Lepidozia pinnata. Grimmia funalis was seen in a most unusual habitat - non-basic rocks where exposed to occasional sea spray.

One day on the low ground was spent south from Ullapool, all in v.c. 105. The first stop, a promising-looking stream at the Braes of Ullapool, produced nothing of interest. Ash trees at the roadside between Foich Lodge and Glackour yielded Zygodon viridissimus var. vulgaris* and several Orthotricha, including a strong candidate for O. shawii; but it proved to be only an arboreal form of O. rupestre. The Corrieshalloch Gorge at Braemore, also visited again by a few members, was more profitable. The slopes between the river and the road had Dicranella schreberiana, Ephemerum serratum*, Fossombronia foveolata* and F. wondraczeki*, while in the gorge itself were Tetraphis browniana*, Hygrohypnum eugyrium, Hypnum cupressiforme var. mamillatum, Plectocolea paroica*, Calypogeia suecica, Eremonotus myriocarpus*, Cephalozia catenulata, C. leucantha, C. media, Radula aquilegia and R. lindbergiana. The afternoon was occupied by a visit to the hazel scrub near Durnamuck on the shore of Little Loch Broom, where is an old record for Leiocolea gillmanii. This was not found, only an abundance of L. bantriensis. Also seen here were Barbilophozia atlantica* and Tritomaria exsecta.

A number of additional plants of interest were collected at various times during the fortnight, quite apart from the official excursions. One car-load went to Durness and visited the Smoo Cave where they found Fissidens pusillus*, Distichium inclinatum and Amblystegium compactum, stopping on the journey just north of Kylesku to collect Cephaloziella hampeana*, both localities being in West Sutherland (v.c. 108). In West Ross Campylium polygamum* was found at the mouth of the Ullapool River, the Society paid homage to Lophocolea fragrans in a cave by the sea at Ardmair, its northernmost British locality, and Polytrichum commune var. perigoniale* was seen by the roadside between Ardmair and Ullapool during an involuntary stop because of work on the road.

On the whole the meeting was lucky with the weather. Although there were not many days suitable for the mountains there were none of those very wet days so common in the west of Scotland where time spent in the field may be a duty but is certainly no pleasure. All members saw species new to them and well over a hundred new vice-county records were made. Most of these of course were mere 'gap fillers', but there were many extensions to range. Cratoneuron commutatum var. virescens was new to Scotland. New to the northern Highlands, i.e. not previously found north of the Great Glen, were Seligeria tristicha, Encalypta alpina, Grimmia trichodon, Ephemerum serratum var. minutissimum, Bryum warneum, Marchantia polymorpha var. alpestris, Lophozia opacifolia, Sphenolobus hellerianus, Calypogeia sphagnicola and Scapania scandica. Considerable extensions were made to the known range of Anomobryum concinnatum, Bryum calophyllum, Marsupella sprucei, Lophozia obtusa, Cephalozia catenulata, Cephaloziella hampeana, Calypogeia suecica, C. trichomanis and C. neesiana, and there were lesser extensions to the range of many more.

Finally, some remarks on the species not seen. The complete absence of some mosses very common over most of the British Isles - Dicranoweissia cirrata, Tortula laevipila, Aulacomnium androgynum, Homalia trichomanoides - was no surprise to those familiar with the western Highlands. But even of oceanic species there were some notable absences, and it is clear that the Ullapool district is less rich in them than many areas farther south. Campylopus shawii and Mylia cuneifolia were not seen, though Ullapool is well within their geographical range. Rhabdoweissia crenulata, Neckera pumila and Sematophyllum novae-caesareae apparently reach only to Kintail, Daltonia splachnoides to Torridon. Details such as these cannot be shown by the present vice-comital system of recording and illustrate the need for accurate distribution maps of British Bryophytes.

A.C. CRUNDWELL

* = New Vice-County Records throughout.

 

Weekend Meeting 1960

Oxford, 29-30 October

Dr E. F. Warburg and Mr A. J. E. Smith organized the meeting which took place on 29 and 30 October 1960, in the Botany Department of Oxford University (by kind permission of Prof. C. D. Darlington).

The President, Miss E. M. Lobley, was in the chair on the Saturday and forty-one members and visitors were present to hear the following papers:

Dr K. R. LEWIS: 'The genetics of Bryophytes'. This paper is printed on pp. 111 - 130.

Dr M. C. F. PROCTOR: 'Epiphytic bryophyte communities in the Dartmoor oakwoods'.
The Dartmoor woods fall into two main groups: three small but well known woods (including Wistman's Wood) on the granite plateau, above the 1000 feet contour, and receiving a rainfall of c. 60-70 inches a year; and a much more extensive and varied series of woods, mostly below the 1000 feet contour, in the deep river valleys cut into the granite and Culm Measures round the edge of the Moor.

In the driest valley woods, the tree bases are generally occupied by Isothecium myosuroides, with Mnium hornum, Dicranum scoparium, etc. This gives way above to a zone of Hypnum cupressiforme var. filiforme, with scattered Dicranum scoparium, and this in its turn to a zone rich in lichens, especially in well-lighted situations. The upper branches carry an open Ulota-Frullania dilatata community. The Ulota-Frullania community may persist on the trunks of coppice oaks until they reach a diameter of 25 cm. or so, and is then often somewhat richer in species, with Neckera pumila, Orthotrichum lyellii, O. striatum, etc. Hazel and ash bear similar Ulota-Frullania communities, though on ash the Ulotas tend to drop out of the later stages.

In the higher and wetter valleys the bases are still covered with I. myosuroides, often extending for a considerable distance up the trunk, but this gives way upwards to a community consisting largely of Frullania tamarisci and Isothecium myosuroides or Hypnum cupressiforme var. filiforme. Above this the upper branches are often covered with Hypnum cupressiforme var. filiforme, while the younger twigs bear the open Ulota-Frullania community.

In Wistman's Wood and Black Tor Copse the trunks and larger branches are typically covered with a thick mat of Isothecium myosuroides, Dicranum scoparium, Scapania gracilis, etc. This shows indications of a cyclical succession, apparently building up from an open community of which Isothecium myosuroides, Plagiochila punctata and Douinia ovata are characteristic consituents, and which is persistent on the overhanging surfaces of trunks and branches. The upper branches are occupied by Hypnum cupressiforme var. filiforme and the common corticolous lichens ( Hypogymnia physodes, Parmelia spp. etc.), while the Ulota-Frullania dilatata community is usually confined to the highest twigs, and is rather poorly developed.

Transitions between the situation of Wistman's Wood and that in the valley woods can be found in some woods on the granite in the higher parts of the valleys.

Mr P. J. GRUBB: 'The study of translocation in Bryophyta, using radio-active isotopes.'
An account was given of some experiments on Polytrichum spp. designed to investigate the processes involved in the translocation of mineral nutrients. It was concluded that nutrients are drawn up passively into the shoot in the transpiration stream; there is no evidence of an active redistribution such as occurs in the phloem of higher plants. The mineral supply to the sporophyte also appears to be passive, involving no special active absorption in the foot.

Prof. P. W. RICHARDS: ' Campylopus introflexus and C. polytrichoides in the British Isles.'
C. introflexus (Hedw.) Brit. and C. polytrichoides De Not. are regarded by Dixon and most other modern British bryologists as synonymous. Giacomini has, however, shown that they are well defined species with distinct distributions, the former being found mainly in Australia and the Americas, the latter in Europe, Africa and tropical Asia. C. introflexus was first found in Europe in 1954 by R. B. Pierrot and P. Stormer who recognized it independently in a locality in Finistère (France). No British record is known previous to 1941, but there is evidence that the species is spreading rapidly and occupying a much larger area than C. polytrichoides which is confined to South-west Ireland, North Wales, Pembrokeshire and south-west England and shows no signs of spreading.

C. introflexus tends to occur on peat, often where it has been burnt or recently cut, while C. polytrichoides grows in rocky habitats. The hair point, short and more or less straight in C polytrichoides, long and usually abruptly recurved in C. introflexus, is an obvious difference between the two species. Dr E. F. Warburg kindly read the paper on behalf of Prof. Richards who, unfortunately, could not attend.

Dr F. ROSE: 'Bryophyte associations in the British Isles - some observations on community structure.'
While much work has been carried out on the Continent on bryophyte sociology, little has been done in the British Isles. A short history of foreign attempts in this direction was first given. The methods and aims of classifying and describing bryophyte communities were then discussed. The bryophyte community is a reflexion of the complex of environmental factors in its particular habitat: so, in so far as the community possesses distinctness and homogeneity, the environmental complex is a distinctive reality. Therefore any objective system of bryophyte community description and delimitation must: (1) show a reasonably constant correlation between the habitat factors and the structure of the community (a point often ignored abroad), and (2) be so designed that any other competent worker can also recognize the units and use the descriptive techniques.

To produce a satisfactory and sufficiently objective technique of description, quantitative methods must be used where possible, though the experience of the skilled field botanist in recognizing communities initially is not to be ignored.

Degree of association appears in practice to be more important than measurement of absolute cover: the latter is very difficult to carry out accurately, and very time-consuming. Units can best be determined by specific composition, but are of little objective value unless a fair proportion of the species show a high degree of constancy and indeed fidelity to the association. Simple statistical techniques for assessing degree of association and coefficient of difference were discussed, and a number of examples of well-characterized bryophyte associations with a number of species in each of high constancy, were described; examples quoted included wet-heath, Sphagnetum of acid bog, rich calcareous Schoenus-fen, and chalk grassland north slope terrace associations.

On Saturday evening, the subcommittee convened to deal with the bryophyte mapping scheme met and, later, at a conversazione held in the Botany Department, mapping cards were on sale. The following exhibits were presented: Studies of variation in Amblystegium (W. M. M. Baron); Cytological studies in the genus Dicranum (D. Briggs); Mire Bryophytes from Swedish Lappland, Mosses from British Quaternary Deposits (J. H. Dickson); British species of the Plagiothecium denticulatum-sylvaticum complex (S. W. Greene); Recent additions to the British Hepatic Flora (Dr E. W. Jones); Variation in Sphagnum imbricatum, S. strictum and S. compactum (Miss E. M. Lobley); Southbeya tophacea new to Britain (Mrs J. A. Paton); Campylopus introflexus and C. polytrichoides (Prof. P. W. Richards); Microfilm of anatomical studies of Mosses (Dr L. B. C. Trotter) (Dr Trotter has generously presented this microfilm of his work to the Society); Recent additions to the British Moss Flora (Dr E. F. Warburg); Stereoscopic colour transparencies of Tortula stanfordensis and Gongylanthus ericetorum at the Lizard, Cornwall (Dr and Mrs H. L. K. Whitehouse).

On Sunday, a fine, dry day, twenty-two members set off by coach (since private transport was not forthcoming) to White Horse Hill in Berkshire, v.c. 22. First, a stop was made in Oxford itself, where Octodiceras fontanum was seen growing on the stonework of the canal at the junction of Hythe Bridge Street and Upper Fisher Row.

The time spent at White Horse Hill gave members the opportunity to see common chalk grassland species as well as a few rarer ones, namely, Barbula acuta, Ephemerum recurvifolium, Pottia caespitosa and Weissia sterilis, all of which occurred on Dragon Hill. After lunch, the party proceeded to Cothill where the majority of members visited the gravel pits. The most noteworthy species found were Bryum intermedium, B. pendulum and Preissia quadrata. A few members botanized a nearby fen, dominated by Schoenus nigricans and Juncus subnodulosus, and saw various fen mosses, including Campylium elodes, Drepanocladus revolvens var. intermedius, Mnium pseudo-punctatum and Mnium seligeri.

Thanks are due to the Oxford Botany Department for supplying refreshments free of charge and Dr Warburg and Mr Smith are to be congratulated for a completely successful meeting.

JAMES H. DICKSON

 

 
 
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