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Meetings of the BBS - 1975

 

Spring Field Meeting 1975

Newtown, 2-7 April

The spring meeting was based on Gregynog, near Newtown, a country house belonging to the University of Wales. In all , about 35 members attended, though there were seldom more than 20 on the excursions. The excursions were mainly in Montgomeryshire (v.-c. 47) with sorties into Shropshire (v.-c. 40) and Merioneth (v.-c. 48). Except where stated below localities are in v. -c. 47.

2 April. Members drove to Llawryglyn and explored the wooded valleys above Gwernafon. Dicranodontium denudatum, Fissidens celticus, Anastrepta orcadensis, Lepidozia pearsonii, L. pinnata, Odontoschisma denudatum* and Scapania umbrosa were found on banks and rotten wood. A small ravine, difficult to negotiate without getting wet and hard to climb out of without getting muddy, provided Tetraphis browniana* on dripping rocks. Next stop was Dylife. To our surprise the public house was being "antiquated" and its plastic trappings removed. The bar was a trestle table. Refreshed, we drove down to Pennant and explored the valley below Ffrwd Fawr. Banks and flushes produced Polytrichum nanum, Sphagnum subsecundum var. subsecundum*, Barbilophozia barbata, Diplophyllum obtusifolium*, Marsupella funckii and Scapania scandica*. Eurhynchium alopecuroides grew in a stream, and on rocks nearer Ffrwd Fawr members saw Campylopus subulatus, Gymno mitrion concinnatum*, G. obtusum* and Plagiochila punctata.

* = New vice-county record.

3 April. The morning stop was Roundton, a small rocky dolerite hill near Church Stoke. Rocks and earth at the base of the hill produced Philonotis capillaris, Rhodobryum roseum and Frullania fragilifolia. On the south side of the hill, members were gratified to find Tortula canescens* in some quantity and with perfect capsules. There were several other xerophilous and thermophilous plants, including Bryum elegans*, Encalypta vulgaris, Grimmia conferta*, Pottia lanceolata*, Pterogonium gracile, Weissia crispa var. aciculata*, W. microstoma* and Barbilophozia barbata. Sheltered habitats nearby produced Eurhynchium speciosum* and Plagiopus oederi*. In the afternoon the party split up, a contingent visiting Snailbeach Mines (v.-c. 40) where they recorded Pottia starkeana*. The majority, however, went up Ashes Hollow on the Long Mynd (also v.-c. 40), accompanied by Mr. J. R. Packham and Mr. C. A. Sinker. On the way up we saw Bryum flaccidum*, Grimmia montana, Mnium seligeri, Philonotis calcarea, Zygodon conoideus, Leiocolea bantriensis and Reboulia hemisphaerica. By the time we reached the top, snow had covered up Bryum weigelii, a speciality of the area. Mr. Sinker instructed us where to dig, and we soon came on its elegant pink mats.

A Council meeting was held at Gregynog in the evening.

4 April. Having driven long distances on the previous days it was pleasant to visit the valley above Mochdre, near Newtown. Here we were led by Mr. R. R. Lovegrove of the R. S. P. B., who had kindly sought permission of numerous land owners, enabling us to go for three miles in continuous woodland, uninterrupted by roads or houses. Lower down the stream had cut into damp calcareous shales, which supported a characteristic flora, including Gymnostomum aeruginosum, Isopterygium depressum, Mnium stellare, Neckera crispa, Pohlia cruda, Rhynchostegiella teesdalei, Porella cordaeana, P. laevigata and P. platyphylla. Plagiothecium latebricola* was also seen in the lower part of the valley. Higher up the banks became acid and we saw little of note. In the afternoon we visited the Dugwm Rock near the top of the same ridge. The Dugwm, like the Mochdre valley, had not been explored previously for bryophytes, and was a complete surprise. Members expected to find an acidic rocky outcrop suitable for Grimmia spp. What they found instead was a deep, sheltered, highly calcareous gorge with sheets of fruiting Cratoneuron commutatum and Ctenidium molluscum and Hygrohypnum luridum. In more specialised habitats were a number of uncommon and rare species, including Amblystegiella sprucei*, Anomobryum concinnatum*, Barbula spadicea, Grimmia conferta, Orthothecium intricatum, Philonotis calcarea*, Blepharostoma trichophyllum, Cololejeunea calcarea*, Leiocolea bantriensis*, Plagiochila punctata, P. tridenticulata* and Scapania aspera.

5 April. When we awoke the world had been purified by a good fall of snow. The planned excursion was postponed. Instead, members explored the Severn valley, from Newtown down towards the English border. River banks in various places produced Epipterygium tozeri*, Myrinia pulvinata, Orthotrichum rivulare, O. sprucei, Scleropodium caespitosum and Tortula stanfordensis (all seen several times). Meanwhile another party visited Llanymynech Hill, recording Barbula acuta, Funaria muhlenbergii, F. pulchella*, Pleurochaete squarrosa, Pottia bryoides*,P. davalliana*, P. recta*, Leiocolea muelleri* and - a complete surprise - Scapania calcicola* in its first British station outside Scotland. In the afternoon, one party went to Sweeney Mountain (v.-c. 40), recording Gyroweisia tenuis, Tortula marginata and Nardia geoscyphus* on sand rocks. Nearby, Leucodon sciuroides was seen on an apple tree. Another party went to Cwm Llech near Pennant Melan gell. In open woodland an ash tree had recently fallen, and on branches about 6 m above the base grew Habrodon perpusillus* and Zygodon viridissimus var. vulgaris. Presumably this would be their natural habitat in climax woodland, rather than on the isolated tree boles which are their familiar habitat at present.

6 April. Next day most of the snow had melted and we went to the north end of Lake Vyrnwy. In valleys and on rocks a number of interesting plants were seen, including Anoectangium aestivum*, Cryphaea heteromalla, Isopterygium pulchellum, Sphagnum warnstorfianum, Lepidozia pearsonii and Riccardia latifrons. A surprising find was Cryptothallus mirabilis on the surface of the litter in a very dark spruce plantation. Probably it had been exposed by heavy rains earlier in the season. On the way over to Llanymawddwy cars stopped briefly at Bwlch y Groes (v. -c. 43), and Grimmia conferta* and Pohlia elongata were found by the road. The valley of the Afon Pumryd (v. -c. 48) was less interesting than had been expected, with only Atrichum crispum, Bryum bornholmense*, Eurhynchium alopecuroides, Isopterygium pulchellum, Seligeria recurvata, Anastrepta orcadensis, Hygrobiella laxifolia and Marsupella funckii worthy of mention.

7 April. First stop was Clegyrnant, near Mynydd Rhiw Saeson. There was little that we had not seen earlier on the meeting, but Dicranella subulata, Drepanocladus revolvens var. intermedius*, D. vernicosus, Rhabdoweisia denticulata, Anthoceros husnotii* and Barbilophozia atlantica were additions. Finally we went to Cwm Cywarch (v.-c. 48), whose magnificent crags swarmed with orange climbers like spider mites. Savage sleety squalls kept most of the field to the lower ground, where they found Barbilophozia barbata, Cephaloziella stellulifera, Leiocolea muelleri and Scapania scandica. Those who reached the crags reported Campylopus setifolius, Dicranodontium denudatum var. alpinum, Ditrichum zonatum, Rhacomitrium ellipticum, Bazzania tricrenata, Blepharostoma trichophyllum, Cephaloziella pearsonii, Gymnomitrion concinnatum, G. crenulatum, G. obtusum and Herberta adunca.

On various days members had stopped by the River Severn on their way back to Gregynog. Grimmia retracta, Tortula laevipila var. laevipiliformis* and T. papillosa* were found in this way near Welshpool, and Fissidens crassipes near Newtown. One member in particular searched - mainly by the Severn and Wye - for tuberous mosses. Many vice-county records resulted: Bryum sauteri 42*, B. violaceum 43*, 47*, Dicranella staphylina 42*, 43*, and Tortula stanfordensis 37*. 40*. 42*, 43*. Mid Wales in general, and Montgomeryshire in particular, had hitherto been rather neglected. It was agreeable to find that the neglect was undeserved.

M. O. HILL

 

Summer Meeting 1975

Arklow, Co Wicklow, 16-30 August

The Summer meeting was held from 16 to 30 August. It was centered at Arklow, Co. Wicklow. Six people attended. In the following account Irish National Grid references are given. Localities are in v.-c. H. 20 unless otherwise stated.

17 August. David McArdle (1890) reported that Lough Bray (32/1315) in north Wicklow was rich in hepatics. He recorded 67 species including Frullania fragilifolia, Porella thuja, Bazzania trilobata, Harpanthus, Herberta adunca, Marsupella sphacelata, Moerckia hibernica and Pallavicinia lyellii. None of these species was among the 27 hepatics recorded on the 17th. The ground about the upper lake was searched from the shore to about one third the way to the top of the cliffs and further into some of the gullies. Barbilophozia floerkei, Calypogeia neesiana var. neesiana*, Lepidozia trichoclados, Lophozia incisa, Sphenolobus minutus, Dicranum scottianum, Isothecium holtii and Sphagnum fimbriatum were the most notable species found. Boggy, N-facing fields at Glencree (32/1615) had Cephalozia leucantha*, C. pleniceps*, Lepidozia sylvatica* and Riccardia latifrons*. Oak woodland in the valley bottom interplanted with conifer s had Plagiochila spinulosa, Solenostoma sphaerocarpum, Eurhynchium alopecuroides and Isothecium holtii. Dr. Pitkin pointed out Riccia huebenerana at Vartry reservoir (32/1903) where Fossombronia foveolata* was also found.

* = New vice-county record

18 August. The Devil's Glen (31/2398) is a deep, wooded river-glen running W. - E. In the river, the Vartry, Porella pinnata is abundant. Dark shaded streams have Jubula hutchinsiae. Lophocolea fragrans is on large flat rocks in deep shade. Neckera crispa and Marchesinia mackaii were found on one outcrop by the river path. Anthoceros laevis*, Cephalozia hampeana, Diplophyllum obtusifolium, Frullania fragilifolia, Lejeunea lamacerina var. azorica, Lophozia incisa, Metzgeria conjugata, Nowellia curvifolia, Porella laevigata, Riccardia palmata*, Riccia glauca, Solenostoma triste, Tritomaria quinquedentata, Cirriphyllum crassinervium, Eurhynchium alopecuroides and Pterogonium gracile were all found in the stretch of over a mile between the castle and the waterfall. Pennycomequick Bridge (31/2778) had Tortella tortuosa; sand-dunes nearby had Eurhynchium megapolitanum and Brachythecium albicans*; clay banks of streams on the west of the road had Epipterygium tozeri* and Funaria fascicularis.

19 August. Spent in Wexford (H. 12). The river, clay banks and scrub west of the bridge south of Clonough Bridge (31/2066) produced Cryphaea heteromalla, Epipterygium tozeri*, Fontinalis squamosa, Leskea polycarpa*, Orthotrichum stramineum, Metzgeria fruticulosa, Pellia neesiana and Riccardia sinuata. Rocky sea shore and clay banks at Clones Strand (31/2464) had Barbula tophacea, Desmatodon convolutus and Pottia crinita and an as yet unidentified maritime Bryum. The bryophytes of Tara Hill (31/2162) are calcifuge. An undistinguished list includes Dicranoweisia cirrata. Tortula ruraliformis was on a tiled roof in shade. At a forestry track and gateway south of Killinierin (31/1665) Anthoceros laevis*, A. husnotii*, Fossombronia wondraczeckii, Lejeunea ulicina and Metzgeria fruticulosa were found. The first Irish record was made of the segregate of Bryum bicolor with numerous small yellow bulbils, first noted in 1948 f rom Cassington Oxfordshire (Trans. Br. bryol. Soc. 1, 245-6, 1949). At Pallis Bridge (31/1168) Dicranella schreberana, Hypnum lindbergii, Orthotrichum striatum and Thuidium delicatulum* were noted at roadside and scrub. Streams and moorland at Croghan (31/1271) on the south side of Croghan Mt. had Acrocladium stramineum, Breutelia, Campylopus atrovirens, Fontinalis antipyretica var. gigantea*, Sphagnum contortum, Calypogeia muellerana* and Scapania irrigua.

20 August. The North Prison (31/0392), which is a west-facing lakeless corrie on Lugnaquilla, was the objective. We crossed the Avonbeg River in Glenmalur at Baravore Ford and struck up through the forestry plantation and over the ridge on the left to the stream, beyond which we picked up the path to the high ground. There is a stiff climb for about 200 ft. and then a level or gently rising part past the stream from Art's Lough (31/055938) until the 1300ft contour is reached. Here there is a waterfall and ascent is to the east of it over very rough and steep but not difficult or dangerous ground. Then we had a further long trudge over rising ground until we took a west branch of the stream at about 1700ft. and a stiff climb to 2700ft. over the spur that runs NW from the summit. We descended into the North Prison in swirling fog and very stiff winds which made mossing somewhat unpleasant and even a little difficult. Gymnomitrion obtusum* was found on the ridge and Anastr epta orcadensis* (very rare) in the corrie. Drepanocladus exannulatus, Polytrichum alpinum, Sphagnum quinquefarium, S. robustum, AntheIia julacea, Gymnomitrion crenulatum and Lophozia alpestris were also found but there was little variety to compensate for the arduous ascent.

21 August. A Juncus marsh at the west end of the Upper Lake at Glendalough (31/0996) had Sphagnum fimbriatum, S. squarrosum and Haplomitrium hookeri*, the last growing with Scapania irrigua on sandy peat. Weissia controversa. var. densifolia* was on lead-mine waste of which the roadway is made. Marsupella funckii was on banks by the roadway. At the east end of the Upper Lake there is some rocky woodland which produced Metzgeria fruticulosa, Plagiochila spinulosa Sphagnum girgensohnii, S. quinquefarium and Cynodontium bruntonii. About the stream and waterfall nearby (31/1196) Dicranella rufescens, Isothecium holtii, Hygrobiella laxifolia and Marsupella aquatica were noted (the Hygrobiella record for H. 20 in the Census Catalogue has not been traced).

22 August. Willow carr and oak woodland at the E. end of L. Dan (32/1602) was explored. Acrocladium cordifolium, Atrichum crispum, Drepanocladus uncinatus, Funaria obtusa, Hygrohypnum ochraceum, Isothecium holtii, Sphagnum molle*, Thuidium delicatulum, Cryptothallus* and Lejeunea lamacerina var. azorica were found. The afternoon was spent at Luggala above L. Tay (32/1508). This is a deep wooded gorge with a swift stream of cascades and pools, large granite boulders and flat rock faces. Dumortiera is recorded from here but we did not see it. Atrichum crispum, Eurhynchium alopecuroides, Fontinalis squamosa with capsules, Isothecium holtii, Douinia ovata, Marsupella aquatica and Plectocolea paroica were in and by the stream, Dicranum fuscescens, D. scottianum and Plagiochila punctata on wooded slopes and Hygrobiella on wet sloping rock in steep woodland. NowelIia and Tritomaria exsectifor mis were on rotten logs and Frullania fragilifolia on a fallen tree-trunk.

23 August. The Avonbeg R. at Greenan (31/1487) produced Bryum argenteum var. lanatum*, Dicranella rufescens, D. palustris, Rhynchostegiella pumila, Fissidens polyphyllus, Lejeunea lamacerina var. azorica, L. ulicina and Metzgeria fruticulosa. The Ow R. at Aughavannagh (31/0784) produced Atrichum crispum, Mnium affine, Plagiothecium denticulatum, Fossombronia wondraczekii* and Pellia neesiana.

24 August. Rathduffmore Bog (31/0182) is the only surviving piece of raised bog in Co. Wicklow. Much of the ground is cut over and has Sphagnum squarrosum, Cephalozia macrostachya*, Cephaloziella hampeana, C. subdentata*, Lepidozia setacea, L. sylvatica, L. trichoclados, Pallavicinia lyellii, Riccardia latifrons, R. multifida, R. palmata, R. sinuata and Scapania irrigua. On the intact bog Mylia taylori, Sphagnum magellanicum and two small hummocks of S. imbricatum* were found. Blasia pusilla was on the side of a drain. Rahill Fen (21/8784) in H 13 is ¼ mile S. of Yellowford Crossroads to the west of the T42. The rare sedge, Carex appropinquata, grows there. Rich fen species, Acrocladium giganteum, Bryum pseudotriquetrum, Scorpidium scorpioides, Drepanocladus revolvens, Mnium pseudopunctatum* and Brachythecium mildeanum* were seen. Camptothecium lutescens was found on clay banks. Other notable species were Bryum klinggraeffii*, Dicranella schreberana*, Hylocomium brevirostre. Sphagnum squarrosum, Chiloscyphus pa llescens* and Leiocolea turbinata. Holdenstown Bog (21/8785) nearby is in H. 20. It is a poor fen for the most part with Acrocladium stramineum, Leptodictyum riparium and Sphagnum squarrosum but the vegetation at the centre approaches that of raised bog with Polytrichum alpestre, Sphagnum rubellum and Cephaloziella hampeana. A stretch of the Aughrim R. (3 1/1379) hadDichodontium pellucidum, Fissidens viridulus, Fontinalis squamosa, Grimmia alpicola var. rivularis, Hygrohypnum luridum, Hyocomium flagellare, Chiloscyphus polyanthos, Porella pinnata, Solenostoma pumilum and Hygroamblystegium fluviatile.

25 August. L. Ouler is a corrie lake at 1900ft. under Tonelagee (32/00). It is bounded on the south and west sides by high cliffs with numerous flushes, wet rocks and block scree. These have Amphidium mougeotii, Ctenidium molluscum var. condensatum, Diphyscium foliosum, Anthelia julacea, Barbilophozia floerkei, Calypogeia trichomanis*, Gymnomitrion obtusum, Lepidozia pearsonii*, L. trichoclados, Marsupella sphacelata, M. ustulata*, Plagiochila punctata, Plectocolea obovata and Tritomaria quinquedentata. Leptodontium flexifolium was found on burnt peat and Grimmia patens on boulders by the lake. Disused buildings and mine waste at the old lead workings below L. Nahanagan (31/0998) had Gymnostomum recurvirostrum, Weissia controversa var. densifolia and Cephaloziella stellulifera*. An unusual Dicranella varia with stems over 9 cm long, showing 5 - 6 annual growth increments was found on a dripping bank on the north side of the road.

26 August. The day was spent in Wexford (H. 12). Duffcarraig rocks on the coast (31/2158) had Grimmia maritima, Tortella flavovirens and Leiocolea turbinata. Near the bridge on the L3 east of Courtown (31/1856), Omalia, Neckera pumila, Plagiothecium succulentum, Tortula laevipila and T. latifolia* were on trees by the roadside or in the deep wooded gorge under the bridge. Carraiganeagh Rock (31/1557) is an Ordovician sandstone. It is partly quarried. Bartramia pomiformis was abundant on ledges and in crevices. Also found were Dicranoweisia cirrata, Epipterygium tozeri, Orthotrichum pulchellum*, Metzgeria fruticulosa and Radula complanata. A boggy field at Whitewood (31/0454) had Acrocladium cordifolium, Drepanocladus exannulatus var. exannulatus and Pellia neesiana. The R. Bann is a tributary of the Slaney. At a bridge north of Camolin (31/0753), Dicranella rufescens*, Epi pterygium tozeri, Funaria attenuata*, Orthotrichum sprucei*, O. diaphanum and Porella pinnata* were found. Sphagnum contortum and Drepanocladus exannulatus var. exannulatus were found in the valley at Slieveboy (31/0258). A bridge ¾ mile NE of Knockbrandon (31/0763) had fine tufts of Distichium capillaceum*. Bryum radiculosum was found nearby. A quarry at Cummer Vale (31/0666) had Barbula hornschuchiana, Hypnum lindbergii, Lophozia bicrenata and Riccia sorocarpa.

27 August. In H. 13, ¾ mile E. of the Nine Stones (21/8254) a stream has dug out a V-shaped defile on the N.side of Mt. Leinster. Funaria obtusa*, Anthelia julacea*, Barbilophozia floerkei*, Lepidozia trichoclados, Lophozia incisa*, Nardia compressa*, Riccardia latifrons and R. multifida* were recorded. On the Wexford side (H. 12) of Mt. Leinster at Cloroge (21/8449) flat moorland and forest tracks, drains and walls had Bartramia pomiformis, Ditrichum cylindricum, Drepanocladus fluitans var. falcatus*, Gymnocolea inflata, Lepidozia trichoclados* and Marsupella funckii*. A stream and boggy field on SE side of Black Rock Mt. , H. 12 (21/8650), had Dichodontium pellucidum, Cephalozia connivens*, Lepidozia setacea* and Riccardia latifrons.

28 August. The morning was spent in Glencullen R. Glen at Enniskerry (32/2118). This area is covered with calcareous drift. The river flows between steep banks and is approached from the T43 by an open forestry road. Brachythecium glareosum, B. mildeanum*, Philonotis calcarea, Leiocolea badensis and Plectocolea hyalina were found on the track and Barbula spadicea, Cratoneuron commutatum, Eucladium, Fissidens rufulus*, F. curnowii*, Rhynchostegiella teesdalei, Trichostomum crispulum var. elatum*, T. tenuirostre, Solenostoma triste and S. pumilum by the river. Powerscourt waterfall (32/2012) , a favourite collecting ground for 19th century bryologists, is an impressive cascade. The cliffs in the immediate area of the fall are rather dangerous with loose rock and unstable boulders. It has the usual Wicklow species of acid rock and swift-flowing stream. The following were noted, Eurhynchium alopecuroides, Isothecium holtii, Rhynchostegiella pumila, Cephaloziella starkei, Nardia compressa, Nowellia curvifolia and Solenostoma sphaerocarpum. Orthotrichum Lyellii and Leucodon sciuroides were on the oaks in the park. Ephemerum serratum var. serratum was found at the dried up northern end of the Vartry reservoir (32/2006).

29 August. A badly poached Sphagnum fen to the N. of Avoca (31/2181) had Dicranum bonjeanii, Drepanocladus exannulatus var.rotae*, Sphagnum fimbriatum, Splachnum ampullaceum, Cephaloziella stellulifera, Lepidozia setacea, Riccardia latifrons, R. multifida and large mats of Solenostoma crenulatum. Chiloscyphus pallescens* was found in a small marshy field nearer Avoca. South of Avoca the river is polluted with washings from the copper mines. Woodland, railway track and riverside here had little that was unusual.

During the meeting a list was compiled for the Arklow town area, sea wall, riverside, waste ground and fields. It includes Barbula hornschuchiana*, B. microerythrocarpum*, Funaria fascicularis, Tortula ruralis and Dicranella rufescens.

I wish to thank Dr. Pitkin for his help on the meeting and Mrs. Paton and Mr. Perry for dealing so cheerfully with the extra work that a small but long meeting imposed on them.

REFERENCE

McArdle D. (1890). Hepaticae of Loughbray, Co. Wicklow. J. Bot. 28, 356 - 360

D. SYNNOTT

 

AGM & Symposium Meeting 1975

Reading, 20-21 September

The annual meeting was held on the weekend of 20-21 September in the Plant Science Laboratories at the University of Reading by kind permission of Professor V. H. Heywood. About forty-five members and guests attended on the Saturday when the President introduced six speakers, summaries of whose papers are given here.

Dr. E. V. WATSON (Department of Botany, University of Reading):'Changing views on the evolution of the Bryophyta.'

This paper was concerned with 'macro-evolution', or the general questions of the origin of the Division Bryophyta and the inter-relationships between major orders of both liverworts and mosses. Attention was drawn to the contrast between the relatively conservative statements which continued to appear in many modern textbooks and the highly iconoclastic views put forward in some contemporary papers. A good example of the latter was 'A new look at Evolution and Phylogeny in Bryophytes' by W. C. Steere. The co-existence of so manifestly contradictory statements could only lead to confusion in the minds of students. Examples were given of such contradictions, both as regards putative origins of the group and in connection with evidence for inter-relationships. By contrast, the position some sixty to seventy years ago was seen to have been a much more stable one. Older authors such as Cavers, Campbell and Bower were cited. Whilst adhering to a particular body of morphological evidence in reaching their conclusions, some of these authors (e.g. Cavers) were more cautious in making their pronouncements than they had sometimes been given credit for. The modern tendency was to undervalue morphological evidence and, in extreme cases, to attempt to undermine the basic tenets of morphology. Some reasons for this were sought.

Mr. M. O. HILL (Institute of Terrestrial Ecology, Bangor): 'Why is Sphagnum considered to be a difficult genus? '.

Various inter-related factors have contributed to make Sphagnum difficult in Britain: unfamiliar morphology, out-of-date floras that either lump too much or split too much, great plasticity, and two pairs of taxa that have not been properly understood even by the experts. Plasticity is undoubtedly the basic problem; several pairs of good species can only be separated by 'soft' characters, none of which is individually reliable. British sphagnologists have incorrectly interpreted the distinction between S. rubellum and S. capillaceum - which intergrade completely - and between S. auriculatum and S. subsecundum - which, if properly interpreted, are genuinely distinct with no intermediates.

Dr. R. E. LONGTON (Department of Botany, University of Manitoba): 'Reproductive biology and evolutionary potential in the Bryophyta'.

Bryophytes are commonly considered to evolve slowly. This paper assesses three factors which have been suggested as important in limiting their evolutionary flexibility, the first being the dominance of a haploid generation incapable of shielding recessive alleles in a heterozygous condition. This consideration applies only to genes expressed in the gametophyte while cytological data raise the possibility that most modern bryophytes may be gametophytically at least diploid following doubling of ancestral chromosome complements. In connection with the second point, that evolutionary potential may have been reduced by a widespread abandonment of sexuality, data are reviewed that suggest that most moss species and many liverworts produce spores in vast numbers at least in part of their range. There is little direct evidence of spore germination leading to establishment of mature gametophytes in the field, but bryophytes which produce spores freely appear in general to be more succ essful than those which do not, suggesting that sexual reproduction is effective in the former group. Thirdly, it has been suggested that inbreeding may severely reduce genetic flexibility in the ca. 50% of mosses and ca. 20% of hepatics which are monoecious. Little is known about population structure and the incidence of outcrossing in such taxa. However, the occurrence of hybrid sporophytes in several groups of monoecious mosses, and the degree of ecological and morphological variation in certain mosses and liverworts, indicate that inbreeding is by no means obligate throughout the monoecious forms. Further studies are required to clarify the issues discussed. Meanwhile, it is suggested that the patterns and processes of microevolution in bryophytes may prove more similar to those in flowering plants than is sometimes supposed.

Dr. N. W. ASHTON and Dr. D. J. COVE (Department of Genetics, University of Cambridge): 'Auxotrophic and developmental mutants of Physcomitrella patens'.

Thirty biochemical mutants have been isolated in the haploid monoecious moss Physcomitrella patens: five nicotinic acid auxotrophs (nic¯ mutants), four p-aminobenzoic acid auxotrophs (pab¯ mutants), four adenine auxotrophs (ade¯ mutants), two nutritionally dependent strains which are repaired by proline or argenine (prg¯ mutants), three nitrate non-utilizers (nat¯ mutants) and twelve strains which are resistant to the amino acid analogues, D-serine and p-fluorophenyl alanine.

Eight crosses involving six different auxotroph strains, one of which is also chlorophyll deficient (yellow) have been performed. All of the parental strains are self-sterile but cross-fertile in certain combinations. Progeny from the crosses have been analysed but no linkage has been detected. Self-sterility segregates as a pleiotropic effect of the nic and pab mutations.

Two categories of mutants which are abnormal with respect to gametophore production have been isolated. Mutants of one class produce few or no gametophores (gam¯ mutants); mutants of the other class produce many more gametophores than usual (ove mutants). There are two groups of gam¯ strains. Some can be made to produce gametophores, either by culturing them in the vicinity of an ove strain or by the supply of a cytokinin. The other type is unaffected by either treatment.

One cross involving a gam¯ strain has been made. However, most gametophore developmental mutants are sterile. We are therefore attempting to devise a means of genetic analysis, independent of the sexual cycle, which entails the production of diploid protonemata by the fusion of protoplasts.

Professor G. K. BERRIE (Fourah Bay College, Sierra Leone): 'Spore dispersal and perennation in West African species of Riccia'.

Professor Berrie's paper is to be published in full in the Journal of Bryology and will, therefore, not be summarised here.

Dr. A. J. HARRINGTON (Department of Botany, University of Ibadan): 'Vegetational zonation and the bryophytes of West Africa'.

The major vegetation zones of West Africa are determined primarily by climate, in particular by the mean annual rainfall and its seasonal distribution.

In the dry Sahel and Sudan savanna zones, the few bryophytes recorded occur mainly in riverain habitats or as ephemerals which develop during the wet season, e.g. Riccia spp. A more varied bryophyte flora is found in the Guinea savanna zone and includes such characteristic species as Riccia intermedia E. W. Jones and Erythrodontium barteri (Mitt.) Broth. The absence of bryophytes from large areas of savanna is undoubtedly due to the annual burning in the dry season.

In the forest zone, the majority are epiphytic. They can be divided into two groups; sun or high epiphytes which are usually restricted to the crowns of taller trees (e.g. Diplasiolejeunea spp. , Calymperopsis spp.), and shade or low epiphytes which grow on tree trunks and branches in the shade (e.g. Plagiochila spp., many Lejeuneaceae and mosses such as Neckeropsis spp. and Pilotrichella spp.). Bryophytes also occur on living leaves, decaying wood, disturbed soil and termite mounds, and rock outcrops and boulders.

The richest bryophyte assemblages of West Africa are found in forests at altitudes above 1200 m., e.g. in the Loma Mountains of Sierra Leone.

The Annual General Meeting was held after tea. In the evening members were the guests of Professor Heywood and Dr. E. V. Watson at a conversazione at which the following exhibits were displayed:

Dr A.J.E. SMITH: 'A comparison of maps showing distributions based upon vice counties and 10 Km grid squares'.
'A provisional atlas of bryophytes'.
'A checklist of British mosses - Sphagnaceae to Entodontaceae'.
'Illustrations for a new British and Irish Moss Flora'.
Mr. A. R. PERRY: 'Bryologists at work - photographs from the B. B. S. album'.
Dr. H. L. K. and Mrs. M. P. WHITEHOUSE: 'Aspects of the ecology and distribution of Tortula (Hyophila) stanfordensis'.
Dr. J. G. DUCKETT: 'Photographs of British bryophytes'.
Mr. M. V. FLETCHER: 'A collection of living Tortulas'.
Dr. E. W. JONES and Dr. F. ROSE: 'The mystery of Plagiochila ambagiosa solved'.
Dr. M. E. NEWTON: 'Heterochromatin in Pellia'
Dr. E. W. JONES: 'Some African bryophytes and their distribution'.
Dr. E. V. WATSON: A few thalloid hepatics from the living collections at Reading'.

The Society is very grateful to Dr. Watson who acted as local secretary, not only for the organisation of this most successful meeting, but also for making the arrangements for members to stay in Reading University's Wantage Hall over the weekend. This new innovation was very much appreciated by all who took advantage of it.

G. C. S. CLARKE

Three localities were visited on the excursion of 21 September. All were in the area W. S. W. of Reading where Tertiary gravels prevail, limiting the flora to more or less acidophile species. Most habitats were abnormally dry after the exceptional summer. The first locality visited was Silchester Common (v.-c. 12), where the most rewarding ground was in the valley bottom. Here Cryptothallus mirabilis was found under birches, seven species of Sphagnum were noted in the bog, including S. nemoreum and S. fimbriatum; and in the alder carr Radula complanata, Pellia neesiana, Chiloscyphus pallescens c. per. +, Acrocladium cordifolium, Ulota bruchii and U. crispa agg. were seen.

At Tadley Common (also in v.-c. 12) the dried-out 'damp heath' bore extensive patches of Gymnocolea inflata c. per., Campylopus brevipilus and, locally, Cephaloziella starkei and C. subdentata. In the low-lying boggy western end of the common Sphagnum spp. were locally much intermixed with the liverworts Mylia anomala, Lepidozia setacea (female plants) and Odontoschisma sphagni. Some healthy tufts of Dicranum spurium occurred.

In Wasing Woods (v.-c. 22) only the southern extremity was effectively explored and the 'moss layer' was much dried out. The best finds were Leucobryum juniperoideum, growing with L. glaucum (sometimes mixed in a single cushion), and Dicranum polysetum. Liverworts included Calypogeia fissa, C. muellerana, Riccardia pinguis and Scapania undulata, but nothing of great interest. Vegetation on the adjacent gravel-pit area was too undeveloped as yet.

E. V. WATSON

Taxonomic Workshop1975

Cardiff, 15-16 November

The second taxonomic workshop was held on 15 November in the Department of Botany, University College, Cardiff by kind permission of Prof. A.G. Smith, and arranged by the Secretary. It was attended by 17 members and 5 invited guests. As with the first meeting the speakers spoke about various 'difficult' genera, pointing out the problems within them, the pitfalls to avoid and characters to look for in naming material, and how to prepare material for microscopical study.

Dr. A. J. E. Smith briefly outlined the sections of the genus Mnium and provided a key for their determination. Characters for the separation of the species of the section Plagiomnium were discussed and a key to the species handed out. The difficulties involved in the identification of the plants became evident on examination of herbarium material.

Prepared slides of British species of Fissidens were provided by Dr. Smith for the second session, and the means of discriminating the difficult pairs of species, F. viridulus and F. bryoides, F. crassipes and F. rufulus, F. cristatus and F. adianthoides were dealt with.

In the afternoon Mr. M. O. Hill spoke about the genus Sphagnum, emphasising characters that can be used in the field. Of special value are the pigmentation of the antheridial leaves, the general habit, and the orientation and shape of the stem leaves. The best way to identify the species is by first recognising the sections of the genus to which they belong. Until some experience has been gained, microscopic characters for identifying the sections may be found difficult to observe.

Fifteen people took to the field on 16 November in order to try to put into practice some of the hints in identification that they had assimilated on the previous day. The morning stop was a boggy hillside on the south-west side of Mynydd Eglwysilan, about 4½ miles north-west of Caerphilly, v. -c. 41 , specially chosen for the seven Sphagnum species that were known to occur there. The locality was unfortunately extremely exposed and therefore unpleasant, so although ten species of Sphagnum were recorded, including S. teres, the Secretary was not altogether popular. Much of his former popularity was restored, however, by his choice of pub for lunch where most of the party congregated at noon. This was the Rose and Crown, Eglwysilan, which greeted us with a roaring fire, an extremely jovial clientèle and some excellent sandwiches. Mr. Hill won affection from the locals by handsomely contributing to a raffle of items for charitable causes, to an auction of an article of clothing and to the ensuing jollification.

In the afternoon we looked at an old lead mine and the adjoining woodland on limestone south of Pen- how, Draethen Forest on the east side of Caerphilly (v.-c. 41). This was bryologically disappointing.

Thanks are due to all those who made the weekend a success, and especially to Mr. Hill and Dr. Smith. The Society's Curator, Mr S. G. Harrison, had generously arranged for participants to visit the National Museum of Wales on the Saturday evening to see the B.B.S. Herbarium; to him we are very grateful.

A. R. PERRY

 
 
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