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Meetings of the BBS - 1972

 

Spring Field Meeting 1972

Matlock, 5-12 April

The Spring Meeting (5-12 April) was held at Matlock in Derbyshire (v.-c. 57) and was attended by twenty-six people. It was a pleasure to welcome Dr Ilma G. Stone and her husband, from Melbourne, Australia.

5 April. The day was spent exploring Lathkill Dale. The party entered by Haddon Grove and saw Funaria muehlenbergii, Rhytidium rugosum and Ptilidium ciliare in limestone grassland. There was some difficulty in crossing the stream, as it was swollen and flowed through stands of Petasites, which nodded forlornly in the flood. Those who walked round the head of the valley to reach the opposite bank were rewarded with a number of characteristic calcicoles, including Isopterygium pulchellum, Orthothecium intricatum, Plagiopus oederi, Seligeria pusilla, S. recurvata, Metzgeria pubescens, Porella cordaeana, Reboulia hemisphaerica and Tritomaria quinquedentata. Lower down, below Haddon village, several other plants were seen: Amblystegiella confervoides, Cololejeunea rossettiana and Leiocolea muelleri.

6 April. Heavy rain attended our arrival on the gritstone uplands near Chesterfield. Hipper Sick contained a small bog with Cladopodiella fluitans* (among Sphagnum papillosum) and Mylia anomala. Other habitats downstream produced Acrocladium stramineum, Atrichum crispum, Nardia compressa and Solenostoma sphaerocarpum. In the afternoon the party split up and one group went to Oak Hurst near Ambergate, recording Trichostomum tenuirostre, Metzgeria conjugata and Plectocolea hyalina* (on gritstone rocks by a stream).

[* New vice-county record]

In the evening a council meeting was held at the Temple Hotel, Matlock.

7 April. The Saturday excursion was to the Hoptonwood limestone quarries and the Via Gellia. Epiphytes were more plentiful in this area than elsewhere, presumably because the bark is sweetened by fall-out of limestone dust. Orthotrichum affine, O. striatum, Zygodon viridissimus and Frullania dilatata were seen on elder and ash. In terrestrial habitats grew Barbula acuta, Brachythecium mildeanum, Campylium calcareum, Rhodobryum roseum, Leiocolea muelleri and Reboulia hemisphaerica.

8 April. This was the free day, and most of the party went to Dove Dale. Finds were similar to those in Lathkill Dale, and there were a number of others: Amblystegium compactum, Mnium marginatum, Pottia bryoides, Rhynchostegiella teesdalei, Seligeria acutifolia var. longiseta, S. doniana, Marchesinia mackaii, Nowellia curvifolia and Ptilidium pulcherrimum. A small contingent examined a disused lead mine near Sheldon, recording Thuidium delicatulum*.

9 April. The day's excursion was to Ticknall Limeyards, an area of old limeworkings south of Derby. Several calcicoles were seen, including Gyroweisia tenuis c.fr., Pottia lanceolata, Thuidium philibertii and Tortula marginata* (on a sandstone lump). One party then went to Carver's Rocks and found Amblystegium varium, Hypnum lindbergii and Plagiothecium latebricola.

10 April. The final outing was to the Highlow Brook near Hathersage, a steep-sided valley on base-rich sandstone. Tetraphis browniana and Solenostoma pumilum were noted on a sheltered overhang in the valley. Weissia microstoma var. brachycarpa, Calypogeia muellerana c.fr. and Lophozia bicrenata grew elsewhere near Stoke Ford; also Mnium pseudopunctatum, Seligeria recurvata and Pellia neesiana in places up Bretton Clough.

In an area which had been well worked by W. R. Linton at the turn of the century, we could hardly expect to make many new records. Nevertheless it was agreeable to confirm so many of the old localities after 70 years. The epiphyte flora is still restricted by air pollution, leaving Aulacomnium androgynum, Bryum capillare, Ceratodon purpureus, Dicranoweisia cirrata, Dicranum strictum, Hypnum cupressiforme, Orthodontium lineare and Tetraphis pellucida as the principal survivors. Of these, Dicranum strictum appears to have spread considerably in the past few years: it was unknown to Linton, yet we saw it in profusion in most of the localities we visited. Mrs M. Gow organized the excursions and told us many facts of local interest. We are very grateful to her for an interesting and enjoyable week.

M. O. HILL

 

Summer Field Meeting 1972

Lochgilphead & Oban, 26 August-8 September

Lochgilphead

We were pleased to welcome Drs Alan and llma Stone from Melbourne and Dr Eva Lauritzen from Norway.

26 August The first week was spent almost exclusively in v.-c. 101. apart from one day on Beinn Buidhe (v.-c. 98), and as Lochgilphead was our headquarters the more southerly portions of the vice-county were left nearly untouched. We started on 26 August by visiting a nameless loch near Loch Choille-Bharr in Knapdale, where we hoped to turn up Cryptothallus mirabilis* and sure enough, Jim Dickson 'did his thing'—this was a welcome addition to the vice-county list. Rhodobryum roseum was the only other plant of note seen here. We then proceeded to the Stronefield area where there is some variety of habitat. We noted Acrocladium stramineum in peat-bog, and in a shady watercourse nearby we found Fissidens celticus growing as it often does with Calypogeia arguta. On the extensive rock exposures there was quite an interesting assemblage, with Grimmia decipiens var. decipiens and var. robusta, G. stirtonii*, G. stricta, G. subsquarrosa, Hedwigia integrifolia, Pterogonium gracile, and Frullania fragilifolia. The G. decipiens var. robusta was interesting as it showed variation in general appearance and areolation. We ended on some rather better rock which produced Funaria attenuata, Adelanthus decipiens, Colura calyptrifolia, and Drepanolejeunea hamatifolia.

[* New vice-county record]

27 August Reinforcements arrived for our second day which started on Danna. We did not spend long on this delightful island, but plants of note included Acrocladium giganteum, Amblystegium serpens var. salinum, Gymnostomum calcareum, Pottia heimii. Sphagnum subsecundum var. subsecundum*, Tortella nitida, Marchesinia mackaii, and Scapania aspera. On Ulva. just the wrong side of the causeway from the point of view of the Danna flora, Bryum marratii* was found. Then we went to the limestones of Barrahormid where we saw several interesting plants, including Aloina aloides, Tortella nitida, Tortula intermedia, and Targionia hypophylla. We ended the day on the coast south of Crinan, but time did not allow a proper look at this area. Frullania fragilifolia, Lepidozia pinnata, and Marchesinia mackaii were noted. A brief stop at Turbiskill near Tayvallich produced Bryum microerythrocarpum, B. ruderale, and an interesting Orthotrichum whose identity is still uncertain.

28 August Next day we tackled Beinn Buidhe. This is quite a rich hill of just over 3000 ft. We drove up Glen Shira and then followed Brannie Burn, leaving our cars at the end of the road, A number of montane species were found including Acrocladium sarmentosum, A. trifarium, Barbula ferruginascens, Campylopus schwarzii, Conostomum tetragonum, Dicranum falcatum, D. starkei, Grimmia funalis, G. stricta, G. torquata. Oedipodium griffithianum. Oncophorus virens, Orthothecium rufescens, Plagiopus oederi, Pohlia elongata, Anthelia juratzkana, Herberta straminea, Hygrobiella laxifolia, Moerckia blyttii, Plectocolea obovata and, most unexpectedly, Riccia beyrichiana on an earthy bank at 2650 ft alt. Other finds included Distichium capillaceum, Plagiothecium platyphyllum, P. succulentum, Pohlia cruda, P. rothii, Rhabdoweisia fugax, and Gymnomitrion concinnatum, while the vascular flora was quite rich, with Polystichum lonchitis, Poa alpina, and Saxifraga nivalis.

29 August After this rather strenuous day we had a comparatively easy one for our next. We searched an attractive limestone ravine near Torinturk, West Loch Tarbert, and this was quite good. Aphanolejeunea microscopica, Cololejeunea calcarea, Drepanolejeunea hamatifolia, and Harpalejeunea ovata were found, along with Cephalozia leucantha, Hygrobiella laxifolia, Leiocolea muelleri, L. turbinata, Plectocolea obovata, Hypnum cupressiforme var. mamillatum, Sphagnum quinquefarium, and Zygodon conoideus, and on moorland nearby Haplomitrium hookeri* was found. Leaving this excellent place we went next to the Kilberry caves, which were of moderate interest: Fissidens curnowii, Plagiothecium succulentum, Rhynchostegiella tenella, and Marchesinia mackaii were seen, but paddling was, at least for some, an irresistible temptation. Bryum klinggraeffii*, B. sauteri, B. tenuisetum* and Ephemerum serratum var. serratum were collected from oatfields north of Kilberry, and B. riparium from a stubble field at Clachbreck. We ended the day by looking over a small area of limestone near Loch AraiL This produced little apart from Funaria obtusa, Gymnostomum calcareum, and Plagiobryum zierii.

30 August Next day I unfortunately had to desert my post, but the party crossed to Gigha and had some good results, though I suspect the island has limited potential. Noteworthy plants recorded included Bryum sauteri from near Ardminish; Eurhynchium speciosum and Cephaloziella starkei from Port an Duin; and from the Mill Loch and surrounding moorland Anomobryum concinnatum, Bryum microerythrocarpum, Cinclidotus fontinaloides, Grimmia subsquarrosa, Orthotrichum rupestre, Fossombronia wondraczekii, Porella thuja, and Scapania irrigua were found. The gravel workings at Rhunahaorine were visited and Haplomitrium hookeri and Fossombronia incurva were found. A barley field at Ballinnenach, near Campbeltown, produced Dicranella staphylina and Ephemerum serratum var. minutissimum* and an oatfield at Eascairt Bryum riparium and B. tenuisetum.

31 August We spent 31 August in the Ellary area and this was rewarding. At St Columba's Cave we saw Fissidens curnowii, and in the woodland south of Ellary House Leucobryum juniperoideum* was discovered. Other finds here included Tortella nitida, Adelanthus decipiens, Jubula hutchinsiae, and Marchesinia mackaii. On the hill ground to the west of this woodland the only noteworthy plant was Grimmia decipiens var. robusta in very small quantity. On a rough track by Loch Meadhonach we noted Bryum tenuisetum, Pohlia bulbifera, Fossombronia incurva, F. wondraczekii, and Marsupella funckii. An oatfield at Redhouse contained B. riparium in abundance and also B. tenuisetum, and another at Stronachullin B. riparium again and Ditrichum pusillum.

1 September On 1 September one party went to Sliabh Gaoil (1840 ft), the highest point in Knapdale. On the way there. Sphagnum molle* was found on the Moine an t-Saraiche, S. strictum* on Cnoc na Seamraig, S. teres* and S. warnstorfianum* near Loch Fuar-Bheinne, and S. robustum* to the east of the Loch. Other Sphagna seen in the same general area included S. contortum, S. girgensohnii and S. subsecundum var. subsecundum. Sliabh Gaoil is of no great height but some unusual plants occur on it, and we noted Encalypta ciliata, Grimmia atrata, Myurella julacea, Plagiothecium denticulatum var. obtusifolium, Rhacomitrium ellipticum, Cololejeunea calcarea, Gymnomitrion concinnatum, and Scapania subalpina. It was a long walk but I think we all enjoyed it.

Another party visited the Skipness area, and also the ravine at Meall Mhor. In the latter the most noteworthy find was Drepanolejeunea hamatifolia, but the ravine may have more to offer higher up. North of Skipness Dicranum scottianum and Weissia perssonii are worth mentioning, as are Bryum riparium (in another field of oats) and Hypnum cupressiforme var. mamillatum, which were found about Claonaig. The last-named plant has evidently been greatly under-recorded and was found in various places. At Kilmartin (v.-c. 98) Ditrichum pusillum* was found in an arable field, and B. riparium yet again.

Altogether, sixteen new vice-county records were made during the week. It would be wrong to omit a mention of the weather which really surpassed itself. I was told that this was the leader's responsibility, but modesty prevents my claiming any personal credit for this unusual state of affairs. Anyway it was most welcome.

A. G. KENNETH


Oban

2 September On 2 September we regretfully parted company with six members and proceeded to Oban which was to be our headquarters for the second week. All the localities visited during this second week were in v.-c. 98. En route a visit was paid to Creag nam Fhitheach near the head of Loch Craignish. This hill has an interesting calcicole flora, and the bryophytes included Camptothecium lutescens, Gymnostomum calcareum, Orthothecium intricatum, Seligeria doniana, S. pusilla, Cololejeunea calcarea, Metzgeria pubescens, and Scapania aspera. We were retarded too with a magnificent view from the top of the hill. On elders at the Ardfern road junction Tortula laevipila was noted.

3 September On the following day we first visited scattered birch woodland and bog by Lochan Dubh near Barravullin north of Connel. A good selection of Sphagna was seen including Sphagnum magellanicum and S. tenellum c. fr. Pleurozia purpurea was common on wet peaty ground almost at sea-level, and by the loch were Drepanocladus fluitans var. fluitans and Gymnocolea inflata. In the wood the only noteworthy moss was Dicranum scottianum, but the rich hepatic flora included Cephalozia catenulata, Riccardia palmata, Scapania umbrosa and Tritomaria exsectiformis. After lunch the road was taken via Glen Salach to the north shore of Loch Etive at Bonawe Ferry. A gully in the andesite in Glen Salach produced Gymnostomum aeruginosum c. fr., Mnium stellare, Neckera crispa, Ptilium crista-castrensis, Leiocolea bantriensis, and L. muelleri. At Blarcreen Hyocomium flagellare c. fr., Trichostomum tenuirostre var. holtii, and Aphanolejeunea microscopica were noted, and at Bonawe Ferry Archidium alternifolium. which grew in damp spots and at the margin of a salt-marsh.

4 September The venue on 4 September was Ben Cruachan (3689 ft), the approach being made by car to the hydro-electric dam, by courtesy of the North of Scotland Hydro-Electric Board. This facility gave us a 1300 ft advantage in altitude and obviated a long walk. Near the dam two good finds were made in the disturbed ground which had resulted from the construction work. The occurrence here of Aongstroemia longipes* and Fossombronia incurva was of considerable interest, and the resemblance of the habitat to that near Ben Lawers was remarked upon. The ascent of Ben Cruachan was mainly over acid granite terrain. A limited area of better rock produced Orthothecium intricatum and Scapania aspera. The main interest of the day was provided by the north-facing summit rocks at over 3500 ft. Here the most noteworthy species were Andreaea nivalis, Arctoa fulvella, Bryum pseudotriquetrum var. bimum c. fr., Campylopus schimperi, Conostomum tetragonum, Dicranum falcatum, D. starkei, Ditrichum zonatum, Oedipodium griffithianum, Pohlia cruda, Rhacomitrium canescens var. ericoides, Anastrophyllum donianum, Gymnomitrion obtusum, Lophozia alpestris, Marsupella alpina, M. sphacelata, and M. ustulata. During the descent by the south face Philonotis seriata and Scapania uliginosa were found in flushes and, close to the dam, Bryum riparium on a wet rock-face.

5 September On 5 September we visited Lismore in Loch Linnhe between Mull and the mainland. This island is composed almost entirely of Dalradian limestone. Along the raised beach between Achnacroish and Kilcheran, calcicoles were well represented, perhaps the most interesting being Targionia hypophylla, not previously reported from Lismore. Other bryophytes occurring in this area included Anomodon viticulosus, Bryum klinggraeffii*, B. ruderale, Cirriphyllum crassinervium, Ditrichum flexicaule, Eucladium verticillatum, Gymnostomum calcareum, Philonotis calcarea, Rhynchostegiella pumila, R. tenella, Tortula intermedia, Trichostomum brachydontium var. cophocarpum*, Leiocolea badensis*, L. turbinata, Marchesinia mackaii, and Metzgeria pubescens. Some of the party visited Kilcheran Loch and in marshy ground and woodland found Acrocladium giganteum, Funaria attenuata, and Pterogonium gracile. Leucodon sciuroides—a rare moss in Argyll—was found in considerable quantity on an ash near Achnacroish. The return trip to Oban was enlivened by our having to share the limited accommodation on the boat with a flock of sheep!

6 September On 6 September most members elected to visit Glen Nant, south of Taynuilt, where the luxuriant bryophyte flora included Antitrichia curtipendula, Bartramia pomiformis var. crispa, Campylium protensum, Heterocladium heteropterum var. flaccidum, Hygrohypnum ochraceum, Hylocomium umbratum, Isopterygium pulchellum, Isothecium holtii, Neckera pumila, Omalia trichomanoides, Philonotis calcarea, Ptilium crista-castrensis, Rhabdoweisia crenulata, Tetraphis browniana, Thuidium recognitum, Anastrepta orcadensis, Aphanolejeunea microscopica, Cololejeunea calcarea, Drepanolejeunea hamatifolia, Harpalejeunea ovata, Leiocolea bantriensis, L. muelleri, Lepidozia pearsonii, Metzgeria hamata, Mylia cunefolia, Scapania aspera, and Trichocolea tomentella. Of particular interest was a fine patch of male Plagiochila asplenioides about a foot square. Fossombronia wondraczekii occurred by the roadside. Near the limestone quarry north of Kilchrenan Bryum intermedium, Pohlia annotina (male), P. lutescens, Thuidium philibertii, Ulota drummondii, and F. wondraczekii were noted.

7 September On 7 September we headed for Glen Creran in Appin. On a wooded limestone outcrop near Dalnasheen the luxuriant calcicole flora included Anomodon viticulosus, Brachythecium glareosum, Eurhynchium murale, Gymnostomum calcareum, Neckera crispa, N. pumila, Rhynchostegiella pumila, and Porella laevigata. Along the course of the Allt Coire Mulrooney, a tributary of the Creran, the following were noted: Dicranella cerviculata*, Fissidens crassipes, Gymnostomum recurvirostrum var. insigne, Hypnum cupressiforme var. mamillatum, Ulota drummondii, U. hutchinsiae, Orthothecium rufescens, Aphanolejeunea microscopica, Calypogeia suecica, Cephalozia catenulata, Cololejeunea calcarea, Douinia ovata, Drepanolejeunea hamatifolia, Harpalejeunea ovata, Hygrobiella laxifolia, Jamesoniella autumnalis, Leiocolea bantriensis, Marsupella ustulata, Metzgeria fruticulosa, Mylia cuneifolia, Plectocolea obovata, P. paroica, and Tritomaria exsecta. Hypnum lindbergii was very fine on a path in Glen Creran.

8 September had been scheduled for a visit to Ben Sgulaird, a hill with high-level limestone outcrops, but heavy rain deterred most of the party, who visited the Loch Melfort area instead. Three members, however, who braved the elements on Ben Sgulaird were rewarded: after a cold, wet ascent from Taravocan the rain gave way to sunshine, but not without a snow shower which left the surrounding tops with a white covering. To reach the limited areas of limestone around 1800 ft entailed traversing much relatively uninteresting ground. This had abundance of certain of the commoner western hepatics. Species noted on the limestone were Distichium capillaceum, D. inclinatum*, Ditrichum flexicaule, Isopterygium pulchellum c. fr., Myurella julacea, Orthothecium rufescens, Rhytidium rugosum, Seligeria doniana, Cololejeunea calcarea, and Leiocolea muelleri. Elsewhere on the hill we found Bryum riparium, Dicranum blyttii, Gymnostomum recurvirostrum var. insigne, Rhacomitrium heterostichum var. gracilescens c. fr., Frullania fragilifolia, Herberta adunca, Metzgeria conjugata, and Tritomaria exsecta. Those who visited andesite crags and woodland north of Loch Melfort were disappointed not to find some of the more interesting species of that area such as Grimmia anodon and G. laevigata, but saw Drepanocladus revolvens var. intermedius, Rhabdoweisia denticulata, Rhytidium rugosum, and Porella thuja.

Only six new vice-county records resulted from this second week of the meeting, but in such a well-recorded area this is perhaps not surprising. Record cards for the Bryophyte Mapping Scheme were prepared for seven 10 km squares. These cards aroused considerable interest on the part of our overseas visitors.

A. MCG. STIRLING

 

Autumn Meeting 1972

London (Imperial College), 28-29 October

This year's autumn meeting, which was held in the Department of Botany at Imperial College. London, by kind permission of Professor A. J. Rutter. was the best attended meeting the society has yet held with over sixty members present. On the first day (Saturday 28 October) the President introduced six speakers and summaries of their papers are given below.

Mr P. PITKIN, Commonwealth Forestry Institute, University of Oxford: 'Environmental factors and growth in corticolous bryophytes'.

Culture experiments have shown that bark and water chemistry are important in determining tree preferences and ecological distribution of corticolous bryophytes. The behaviour of Cryphaea heteromalla, Hypnum cupressiforme and Lophocolea heterophylla in sand culture with water extracts of different barks corresponds closely to that in the field. Growth on bark extracts from different heights on a trunk indicates that there may be a growth inhibitor in the bark higher up the trunk to which L. heterophylla seems particularly sensitive. Growth on bark extracts also showed that stem-flow water is an important source of nutrients.

When bark extracts were amended with mineral acid and alkali C. heteromalla and H. cupressiforme were more sensitive to pH than L. heterophylla. Amendment of various bark extracts to the same pH altered their relative suitability for growth. Sensitivity of C. heteromalla and H. cupressiforme was further demonstrated by their growth on artificial culture media. Optimum pH for the growth of these species was 6-6-5 but Isothecium myosuroides showed maximum growth at pH 7. Above pH 5 growth of H. cupressiforme exceeds that of I. myosuroides but in more acid conditions the rates are reversed. Since these species have similar growth forms and occupy similar habitats this may be an important factor in competition between them.

Variations in the pH of oak bark in England and Wales, which have been correlated with atmospheric pollution and rainfall, may be important in restricting the geographical distribution of corticolous bryophytes. Near Oxford the pH of oak bark is about 3-6 and culture experiments show that this is so acid that growth is minimal.

Gemmae of Ulota phyllantha will germinate on discs of oak bark cut from the foot of the trunk beneath epiphyte cover, but they die on discs of uncolonized bark from higher up the trunk suggesting the presence of possible growth inhibitors. Washing seems to remove these from the bark. The effect of tannic acid and Calluna tannin on early stages in the development of H. cupressiforme and U. crispa was studied. Spore germination was unaffected by tannin concentration, but there was a marked effect on the development of sporelings, although U. crispa was considerably more sensitive than H. cupressiforme. This difference is reflected in the ecology of the two species: H. cupressiforme growing on trunks has more tannin in its water supply than U. crispa which grows on twigs.

Professor W. W. SCHWABE, Department of Horticulture. Wye College: 'Growth regulation in Lunularia cruciata and the role of lunularic acid in lower plants'.

The Mediterranean strain of L. cruciata (Israel material) is sensitive to photoperiod in its growth: it becomes dormant in long day conditions. Dormant thalli exhibit considerable drought resistance and may be kept for a number of years in the air-dry state, while actively growing thalli in short days are rapidly killed by dry conditions. There is no sharply defined critical day length for dormancy induction and at higher temperatures relatively shorter day lengths induce cessation of growth. A few short day cycles suffice for growth resumption.

Gemmae require light for 'germination' but will survive for months in total darkness. Both dormancy induction by long days and germination of gemmae are phytochrome controlled in a complex manner involving interactions with temperature. Drastic changes in response to red or far-red light, given in the middle or at the end of the photoperiod. or in the dark period, suggest the involvement of internal rhythms.

The natural growth substances of higher plants (auxins and gibberellins) appear to have little or no promoting effects on the growth of Lunularia and become inhibitory at higher concentrations, as does abscisic acid. However, chelating substances (EDTA) promote growth.

It has been shown that dormancy of thalli and of gemmae in the gemma cup is controlled by the level of a natural growth inhibitor recently isolated and structurally identified (lunularic acid). This substance has since been found in all species of liverwort and algae so far examined, but appears to be absent from mosses, ferns and higher plants. In Lunularia it is quantitatively controlled by photoperiod. It also acts as an inhibitor of algal growth and germination of fungal spores. It delays seed germination in some higher plants.

Dr A. R. SHELDRAKE, Department of Biochemistry, University of Cambridge: 'Auxin and bryophytes'.

Auxin production in higher plants has for many years been thought to take place in meristematic cells, but it now seems probable that it is normally produced as a consequence of cell death, the auxin production of meristematic regions being attributed either to the presence of regressing nutritive tissues (as in embryo, seed and pollen development) or to differentiating vascular tissue: xylem cells die as they differentiate. Attempts to explain the growth of non-vascular plants in terms of auxin production by meristematic cells by analogy with higher plants are therefore misleading and a critical examination of the evidence for the involvement of auxin in, for example, apical dominance in bryophytes and fern gametophytes reveals that it is unconvincing. Nor is there any persuasive evidence that these plants normally produce auxin.

There is, however, one positive response of liverworts to auxin which occurs at low concentrations and which may be of physiological significance' the induction of rhizoids. The response to exogenous auxin could take place under normal growth conditions if auxin is present in the environment. Substrata on which bryophytes were growing were analysed and found to contain amounts of auxin sufficient to induce rhizoids; similar concentrations of auxin were also found in humus-rich soil on which no bryophytes were growing.

This response to environmental auxin, produced during the decomposition of organic matter by soil micro-organisms, may be of adaptive importance in that rhizoids will be induced in regions where nutrients are released. The induction of buds on moss protonemata by low concentrations of cytokinins could perhaps also be a response to environmental cytokinin released from RNA in decomposing organic matter.

Dr D. W. SHIMWELL, Department of Geography, University of Manchester: 'The ecology of moss-dominated vegetation on the heavy metal mine spoil heaps of the Southern Pennines'.

Moss dominated communities are rare on the heavy metal mine spoil heaps of the Southern Pennines and are more or less restricted to areas where the spoil overlies impervious shale and where the habitats are thus suitably moist. Three ecological features are characteristic of these habitats—quantities of lead and zinc toxic to most phanerogams, low concentrations of nitrate, phosphate and potassium and the acidity (pH 4.3-5.2). In the Peak District and Grassington (Yorkshire) regions three species of moss—Dicranella varia, Bryum pseudotriquetrum and Philonotis fontana—are most commonly associated with such habitats, and analyses of tissues and soil samples indicate that lead and zinc concentrations are far greater than those previously reported for mosses. In periods of alternating drought and wetness, D. varia excretes and deposits a crust rich in heavy metals with recorded values of up to 6% Pb and 6000 ppm Zn. In contrast, living tissues contained up to 11,950 ppm Pb and 5985 ppm Zn. P. fontana shows a marked localization of both metals in older tissues (10,015 ppm Pb and 2420 ppm Zn maxima) with comparatively low values in actively growing tissues (to 423 ppm Pb and 297 ppm Zn). Other mosses showing a capacity for heavy metal absorption include Camptothecium lutescens and Encalypta vulgaris. Analyses of twenty samples of Fontinalis antipyretica from two rivers flowing through former lead mining areas indicate low values of both lead (0-10 ppm) and zinc (10-90 ppm).

Dr S. W. GREENE, British Antarctic Survey, Botanical Section: 'The International Association of Bryologists'.

The idea of forming an International Association of Bryologists, affiliated with the International Association of Plant Taxonomists (IAPT), was first discussed at the Pacific Science Congress in 1966 when a steering committee was appointed to report to the next International Botanical Congress of the feasibility and aims of such an association. The formation of the Association was formally proposed and passed by the general assembly of the International Union of Biological Sciences at the Congress in Seattle, 1969. Affiliation with IAPT ensures financial and secretarial support for the Association and the possibility of using its outlets for publication, e.g. Taxon, for a regular Bulletin of Bryology and Regnum Vegetabile for larger specialist works. The first Bulletin of Bryology appeared in Taxon 21 (2/3), 375-6. in May 1972.

The aims of the Association are to promole the study of all aspects of bryology throughout the world by such means as the organization of meetings and symposia, the production of regular news bulletins, special purpose reports and publications, e.g. a periodic list of all new taxa and combinations, an index of types, a detailed register of bryological collections and their locations, etc. Two current projects are a directory of bryologists and their research projects and a conspectus of bryological taxonomic literature, the latter being intended as an introduction to the bryophyte floras of the world arranged on a regional basis.

Dr D. H. DALBY, Department of Botany, Imperial College: 'The BBS in the 1970s'.

The present-day activities of the British Bryological Society can be traced back to its origins as the Moss Exchange Club, which by encouraging comprehensive collecting (in spite of the very high standards of identification attained) did appreciable harm to bryology as a reputable study in Britain.

The major works of bryologists such as Dixon and Macvicar formed a transition to the period of better understanding of the causes of variation of species in nature, with an awareness of the effects of environmental factors. At the same time, the Society has responded to the developing needs of a body combining fieldwork with research, both by amateur and professional members. The question arises as to whether the Society's present activities are adequate, and if they are not, should encouragement be given to a change in emphasis or to entirely new activities?

As a purely personal view, I would favour the following lines of development: 1, greater emphasis on the 10 km square recording and a playing down of the vice-county recording schemes; 2, active co-operation with the Nature Conservancy and other conservation bodies, with the possibility of holding field meetings in nature reserves for the purpose of recording and advising in management plans; 3, the organization of specialist symposia (in conjunction with other biological societies) on such subjects as the physiology of epiphytes, phyto-sociology of cryptogam-dominated communities, etc.; 4. increasing help given to beginners, both by way of reference material and by organizing field meetings where the objective is one of teaching methods of identification and ecological principles; 5, increased publicity for the Society with the objective of both adding to our membership and also improving the image of bryology as a scientific study in this country.

The Annual General Meeting was held at 7.30 p.m. and this was followed by a conversazione at which the following exhibits were presented:

Mr S. G. HARRISON: The Jackett bryophytes; a bound exsiccata.
Mr M. V. FLETCHER: A collection of living New Zealand mosses.
Mr M. O. HILL: An ordination of mosses based on vice-comital distribution.
Dr M. NEWTON: Liverwort chromosomes.
Mosses common to Great Britain and to the sub-Antarctic zone.
Mrs K. LEWIS: Coal pollution effects on Eurhynchium riparioides.
Dr K. BENSON-EVANS, Mr M. GRIFFITHS,
Mrs K. LEWIS and Mr J. MORGAN:
Regeneration studies in some mosses.

On 29 October about twenty members attended a field meeting in Surrey (v.-c. 17) led by the President and Mr J. C. Gardiner. In the morning a visit was paid to part of Box Hill, and in the afternoon a boggy woodland area, a little to the north of Leith Hill, was explored. As might be expected from such well-worked areas only one new vice-county record was reported, but useful additions were made to the existing lists for the 10 km squares. Amongst the 'specialities' from Box Hill, Dicranum montanum, D. strictum, Isothecium striatulum, Thuidium hystricosum, T. philibertii, Tortula stanfordensis and Lejeunea lamacerina var azorica were seen, while additions to the square in the Leith Hill area included Dicranum strictum, Bryum bornholmense, B. violaceum, Pohlia lutescens*, Plagiothecium latebricola and Cryptothallus mirabilis.

[* New vice-county record]

The Society is grateful to the leaders of the field meeting and to Dr D. H. Dalby who acted as local secretary for the weekend.

G. C. S. CLARKE

 
 
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