Meeting report
Bryological symposium
Those of us who attended the paper-reading meeting and annual general meeting at Badock Hall, University of Bristol on the weekend of September 20 – 21, were rewarded by an interesting and stimulating programme in very comfortable surroundings. It was particularly pleasing to be joined by several members, including one from overseas, who were attending their first meeting of the Society. The President and Vice-President introduced seven speakers whose topics were exceptionally diverse, a trend which was warmly welcomed and matched by the wide-ranging interests of the audience. For his skill in establishing such a programme, we are greatly indebted to Prof. J. G. Duckett. Not only were there papers devoted to field work in Britain, Bhutan and Canada, but there were others detailing fine structure of spermatozoids, carbohydrate chemotaxonomy and an analysis of bryophyte communities. Summaries of these papers are given below.
Mr. T. Blockeel (Leeds): “Bryologists and Bryophytes from South Yorkshire.”
Watsonian vice-county 63 (south-west Yorkshire) is the heart of industrial Yorkshire, but the composition of its flora and its recent history has much of interest for the bryologist.
Bryologists of the area have included: James and Thomas Bolton (Halifax), Jonathan Salt (Sheffield), Robert Leyland (Halifax), Samuel Gibson (Hebden Bridge), John Nowell (Todmorden), Amos Carr (Sheffield), Abraham Shackleton (Keighley), Charles P. Hobkirk (Huddersfield), Dr. Franklyn Parsons (Goole), James Needham (Hebden Bridge) and Harold Walsh (Luddendenfoot).
Floristically, the vice-county may be divided into four areas.
- A small part of the north-western tip of the vice-county is Carboniferous limestone, consisting of low rounded hills without the natural scars and river gorges of the Dales to the North. Nevertheless, grassy banks have such species as Thuidium philibertii, and the river-bank flora is better developed than in other parts of the vice-county, with Schistidium alpicola, Orthotrichum sprucei and others.
- The millstone grit and coal measures occupy the entire western part of the vice-county. The richest habitats are in the deep wooded valleys or cloughs, of which the best example is the Hebden gorge north of Hebden Bridge. Here are one or two oceanic plants (Lepidozia cupressina, Jubula hutchinsiae) and many other species, including Andreaea crassinervia, Tetrodontium brownianum, Blindia acuta, Schistostega pennata, Isopterygium pulchellum, Mylia taylori, Saccogyna viticulosa, Nowellia curvifolia and Lejeunea lamacerina. The millstone grit also has a few atypical pockets of highly calcareous material, supporting in single sites Moerckia flotowiana and Cololejeunea calcarea. Bogs are poorly developed, probably because of the effect of acid rains; consequently, the bog hepatics are sparsely distributed. Plants of open habitats include Physcomitrium sphaericum, Discelium nudum, Nardia geoscyphus and Solenostoma caespiticium.
- A narrow strip of magnesian limestone separates the coal measures in the west from the low-level plain in the east. Desmatodon cernuus occurs on quarry waste and Lophozia perssonii on open ground and on the walls of a ruined Abbey. Open calcareous ground also has various small acrocarps including Pottia recta and Phascum curvicolle. In a few places there are wooded crags and valleys, of which the best example is Anston Stones Wood, near Rotherham. Among species known from here are: Metzgeria pubescens, Leiocolea muelleri, Scapania aspera, Marchesinia mackaii, Cololejeunea rossettiana, Distichium capillaceum, Tortula marginata and Amblystegium compactum.
- The eastern part of the vice-county is flat and intensively cultivated. Ricciocarpus natans occurs in ponds, and there are two extensive peat bogs, Thorne Waste and Hatfield Moor. Though both of these are cut commercially for peat, some good plants remain, notably Sphagnum balticum, recently refound on Thorne Waste.
Mrs. A. G. Side (Rochester): “Amateur bryological work in Kent”
The speaker’s amateur work in Kent began with filling in records on the 10 km. record cards of Dr. Francis Rose. Permission was given by Dr. Rose to use the cards in the production of An Atlas of the Bryophytes found in Kent which was published in Kent in 1970 as vol. 4 of the Transactions of the Kent Field Club. Since 1971 mapping had continued but on a tetrad basis, as in the Monks Wood records centre. Such mapping had shown abundance of the species much more clearly than did the 10 km. maps though it entailed much more work.
Types of woodland to be found in Kent were illustrated and some lists of species found in these woods were given. Special emphasis was laid on Ham Street wood where Discelium nudum had been found in 1970. Pictures of Cryptothallus mirabilis, found in other woods in Kent, were shown together with more of the less common species.
Chalk downland, an important feature of the Kentish scene, had special interest for work on Seligeria paucifolia and Fissidens viridulus subspecies tenuifolius, both very common species on chalk stones in downland woods. Thuidium hystricosum and Tortella inflexa were shown as locally abundant species on the chalk.
Brief mention was made of Romney Marsh with its somewhat limited habitats, but with a capacity to produce some interesting mosses.
Work on the bryophytes of arable fields in Kent had occupied much time and patience but was inspired by the pleasure of seeing the various rhizoidal tubers to be found. A number of these tubers were illustrated to show their diversity. The results of this work had been published in Trans. Kent Field Club. volume 6 part 2, 1976.
Finally an interest in the numbers of “failed” archegonia around the bases of the sporophytes of mosses had given this amateur another subject on which to work.
Prof. J. G. Duckett, Dr. W. C. Pang and Dr. Z. B. Carothers (Department of Plant Biology & Microbiology, Queen Mary College, London and Department of Botany, University of Illinois, Urbana, U. S. A.): “Pellia neesiana: the biggest spermatozoid in the bryophytes.”
Pellia neesiana and P. epiphylla have the largest spermatozoids yet recorded for any bryophyte. The mature gametes comprise an 8.5 µm diameter helix of 3½ gyres circumscribed by a band of microtubules (the spline) of about 95 µm in overall length. Although an earlier electron microscope study by Suire suggested fundamental differences between spermatids of Pellia and other bryophytes including branching of the spline over tubular diverticula of endoplasmic reticulum and maturational disappearance of some of its microtubules, our analysis supports a quite different interpretation.
The broad anterior region of the spline (15 tubules in P. epiphylla and 13 in P. neesiana) is retained but is restricted to the first half gyre. The diverticulum in mid-stage spermatids is a tubular extension of the nucleus, devoid of chromatin which runs posteriorly for over 60 µm (2½ gyres) and is overlain by 6 or 7 long, parallel tubules.
Preliminary studies on other Metzgerialian spermatozoids (Petalophyllum, Riccardia, Symphyogyna, Fossombronia) indicate that these are all appreciably larger and more highly coiled than those of the Marchantiales (Dumortiera, Marchantia, Sphaerocarpos, Riella). The parallel orientation of the basal bodies in the Metzgeriales, a feature shared with Haplomitrium, contrasts sharply with their divergent disposition in Marchantia. As more taxa are investigated from all the major groups, but as yet lacking Treubiales and isophyllous Jungermanniales, there is growing evidence that spermatozoid ultrastructure supports Schuster’s phylogenetic scheme for Hepatic evolution.
When the well established criteria of evolutionary advancement from animal spermatogenesis are applied to archegoniates striking parallels emerge. Primitive animal spermatozoids have roughly spherical nuclei with prominent structures anchoring the flagella (analogous to the multilayered structure) whereas advanced taxa possess elongate nuclei and the complex anchoring apparatus is reduced or lost. In the Lycopsida, homosporous Lycopodium has 40 spline tubules and a fat pyriform nucleus whereas heterosporus Selaginella only 17 tubules and a rod-like nucleus. Similarly in the Pteropsida there is a reduction in the number of spline tubules from Osmunda (180) and Pteridium (150) to Marsilea (25) and a concomitant elongation, narrowing in maximum diameter, and degree of coiling of the nucleus from 2 and 3½ to 8 gyres respectively,
Haplomitrium (57 tubules) has by far the widest spline and broadest nucleus (coiled in about 1¼ gyres) yet encountered in the bryophytes which contrasts sharply with the much narrower splines and 3½ gyres of the rod-like nuclei in Pellia and Riccardia. Less highly coiled (24 gyres) and slightly broader splines occur in supposedly less advanced Metzgerialian taxa such as Petalophyllum (22 tubules), Fossombronia (18) and Symphyogyna (17).
Miss A. Christie, Dr. D. H. Lewis (Department of Botany, University of Sheffield) and Mr. A. R. Perry (Department of Botany, National Museum of Wales, Cardiff): “Carbohydrates and chemotaxonomy in the Ptilidiaceae.”
The genera, Anthelia, Blepharostoma, Herberta, Hygrobiella, Mastigophora, Pleuroclada, Ptilidium and Trichocolea were placed in the Ptilidiaceae by Evans (1939) and Jones (1958). Other taxonomists have treated these genera differently and there has been a progressive segregation of genera into several families, culminating in the schemes of Schuster (1972,1979) which recognize seven families for the eight genera.
A correlative evaluation of a range of morphological features of both gametophyte and sporophyte demonstrated that a large number of characters separated Anthelia, Hygrobiella and Pleuroclada from the other five genera. Anthelia was especially isolated.
Within the Jungermanniales, the possession of a particular combination of soluble carbohydrates is chemotaxonomically useful since patterns are consistent within species of one genus and within genera of relatively well defined families, e.g. Cephaloziaceae, Lepidoziaceae and Scapaniaceae. In addition to sucrose, the 7-carbon monosaccharide, sedoheptulose, its reduction products, alpha-sedoheptitol (volemitol) and beta-sedoheptitol, a third uncharacterized heptitol and the 6-carbon sugar alcohol, mannitol, occur in the Ptilidiaceae (s.l.) in seven combinations. These not only emphasize the diversity of the group but also coincide with the families recognized by Schuster (Antheliaceae, Blepharostomataceae, Cephaloziaceae, Herbertaceae, Mastigophoraceae, Ptilidiaceae and Trichocoleaceae). The absence of mannitol and 7-carbon carbohydrates from Anthelia re-inforces its morphological isolation and the presence of mannitol (but absence of 7-carbon carbohydrates) in Pleuroclada and Hygrobiella supports Schuster’s placing of these genera in the Cephaloziaceae.
REFERENCES
EVANS, A.W. (1939).
The classification of the Hepaticae. Bot. Rev. 5, 49-96.
JONES, E.W. (1958).
An annotated list of British hepatics. Trans. Br. bryol. Soc. 3, 353-374
SCHUSTER, R.M. (1972).
Phylogenetic and taxonomic studies on Jungermannidae. Journ. Hattori bot. Lab. 36, 321-405
SCHUSTER, R. M. (1979).
The phylogeny of the Hepaticae. In: Bryophyte Systematics. (Ed. by G. C. S. Clarke and J. G. Duckett). pp. 41-82. Academic Press, London.
Dr. R. W. Alexander (Department of Geography, University of Liverpool) : “Some Bryophyte and Macro-lichen communities on the Pillow Lava Band Rocks of Cader Idris, Gwynedd.”
This paper presented the results of a survey of the bryophyte and macro-lichen vegetation of the pillow lava outcrops on the north face of the Cader ldris range of mountains in the county of Gwynedd. The aims of the work were to sample the vegetation in an objective fashion in order to discover whether any distinct and recurring species assemblages could be identified and, if so, to examine the environmental factors controlling the distribution of such assemblages.
The major problems involved in this type of investigation are those of scale (size and distribution of rock outcrops compared to size of plants and plant communities) and the three-dimensional nature of the substrate surface. These problems could not adequately be overcome by the use of conventional methods of sample distribution and thus a new technique for the distribution of (in this case 10 x 10 cm.) quadrats was developed. This technique operated by superimposing a flexible grid onto the rock surfaces and then sampling randomly from within this grid. Application of this partial random technique gave rise to a data set of 162 quadrats containing 135 species and these data were analysed using Reciprocal Averaging ordination and a polythetic, agglomerative clustering technique. The results of both techniques indicated that the major environmental variables influencing the bryophyte and macrolichen vegetation were base status of substrate and some measure of ‘wetness’ of habitat. At the four-cluster level the quadrats could be divided into ‘Wet calcifuge’, ‘Dry intermediate to calcifuge’, ‘Dry calcicole’ and ‘Wet intermediate to calcicole’ groups on the basis of certain recognised indicator species. These four major groups were further sub-divided into 14 distinct assemblages identified by constant and faithful species, and these 14 assemblages were examined in terms of their interrelationships, ecology and distribution patterns.
Work is in progress to test the validity of some of the conclusions drawn by examining the nutrient status of plants and substrates from type examples of the communities identified.
Mr. D. G. Long (Royal Botanic Garden, Edinburgh): “Bryophyte exploration of Bhutan”.
A brief historical outline of bryological exploration and study in the western Himalayas was given, from the earliest Nepalese collections of F. Buchanan-Hamilton and N. Wallich in the early 19th century, published by W. J. Hooker and W. Harvey, followed in 1848 by the large Sikkim collections made by J. D. Hooker, these largely forming the basis for W. Mitten’s “Musci Indiae Orientalis” (1859) and “Hepaticae Indiae Orientalis” (1861). The only early collector to visit Bhutan was W. Griffith, in 1838, whose bryophyte discoveries remain largely unpublished. The bryophytes of Bhutan were not studied again until a Japanese expedition visited western districts in 1967, from which a check list was published in 1971. Recent work covering some of the bryoflora includes the up-to-date E. Indian moss flora of Gangulee and monographic studies of genera such as Plagiochasma and Sphagnum. Considerable collections, most as yet unstudied, were made by the author in the forests of Bhutan in 1975 and 1979.
The main forest zones of Bhutan were described and illustrated with characteristic flowering plants and bryophytes. The jungle-clad foothills (200-1200 m) are poor in bryophyte species but with increasing altitude the forest changes to warm broad-leaved (1200-2100 m) then cool broad-leaved or evergreen oak forest (2100-3000 m), above which bryologically very rich montane coniferous cloud forest of spruce, hemlock and fir, is found up to an altitude of 3500 or 4000 m. In drier main valleys xerophytic pine forest occurs.
In the cool broad-leaved forests species such as Trachypodopsis serrulata, Meteorium buchanani, Meteoriopsis squarrosa, Herbertus dicranus, Porella campylophylla and Plagiochila chinensis are found, mostly as epiphytes on tree trunks and logs. The montane cloud forests are the richest, with a dense carpet of such species as Lyellia crispa, Actinothuidium hookeri, Ptilium crista-castrensis, Scapania ferruginea, Dicranum lorifolium. On rotten logs are found, for example, Acrobolus ciliatus, Blepharostoma trichophyllum, Lophozia incisa, Metacalypogeia alternifolia and Schiffneria hyalina, whilst common epiphytes are Chandonanthus hirtellus, Trichocolea tomentella, Diaphonodon blandus, Anastrepta orcadensis and many Herbertus, Scapania, Porella, Plagiochila and Frullania species. Aongstroemia orientalis is common on road cuttings in the forest.
In the dry pine forests Rhytidium rugosum was common and Targionia hypophylla, Trocholejeunea sandvicensis and Frullania ericoides were found on dry rocks. In moist paddy-fields the interesting pan-tropical moss Barbula inaequalifolia was often abundant. The world distribution of some of these species was illustrated, of particular interest being the group of hepatics such as Anastrepta, Anastrophyllum and Mastigophora whose origins are considered to have been in the southern hemisphere.
Dr. R. E. Longton (Department of Botany, University of Reading): ” A British bryologist in Canada.”
Canada is a vast country and it is sparsely populated except in the extreme south. It thus contains several million sq. km. of virtually undisturbed natural vegetation, principally coniferous forest and tundra, occurring at a wide range of elevation and climate. There are few bryologists: the second edition of “Directory of Bryologists (I. A. B. 1979) includes only 20 Canadian entries, and of these perhaps 9 can be regarded as established research workers. In contrast to Great Britain there is no strong tradition of cooperation between amateurs and professionals. Thus, despite the vigorous efforts of a handful of bryologists past and present, Canada offers tremendous scope for bryological research across the whole spectrum from basic floristics to the most sophisticated modern studies.
Some of this potential was illustrated by an illustrated account of vegetation in the Province of Manitoba. Among the points noted were the poor state of knowledge of the bryophyte flora of the Province, from which no species of such ubiquitous genera as Cephalozia and Cephaloziella had until recently been recorded, the strong circumpolar element in the boreal bryophyte flora, the high frequency of sporophyte production of Pleurozium schreberi throughout the forest region, the extensive destruction of P. schreberi and other mosses by pollutants from isolated industrial operations, and the use of dried Sphagnum in baby-care by indigenous Canadians.
Conversazione
After the annual general meeting (Minutes in Bulletin 38), members were welcomed by Prof. B. K. Follett, who had kindly arranged an enjoyable University reception on our behalf. The meeting continued in the evening with a conversazione which provided an opportunity to examine a large number of exhibits, as indicated by the following list.
Dr. K. J. Adams: | Some recent library accessions. |
Dr. D. H. Brown: | Bryophytes from the Broome Herbarium Bath. |
Mr. A. C. Crundwell: | Reproduction in Myurium hochstetteri. |
Mr. M. V. Fletcher: | Some cultivated Eurhynchiums. |
Dr. E. W. Jones: | Some hepatics of the “Mist Forest” of tropical African mountains. |
Mr. D. G. Long: | General literature relating to Bhutan. Bryophyte specimens collected in Bhutan, East Himalaya in 1979. Literature relating to east Himalayan bryophytes. Barbula inaequalifolia Taylor |
Mr. A. R. Perry: | Leaves from the B. B. S. Photo album. Logo. |
Dr. C. D. Preston & Dr. H. L. K. Whitehouse: |
Conservation of Eurhynchium pulchellum on Lakenheath Warren, Suffolk. |
Mrs. A. G. Side: | Note books. Bryological work in Kent. a) some new Vice County Records since 1970. b) state of the tetrads. c) mosses not seen by A. G. S. since 1970. |
Dr. H. L. K. Whitehouse: | Agar cultures of some tuber bearing mosses. |
Field meeting
The Sunday excursion was blessed with fine weather, a matter for thanksgiving in such a poor season.
In the morning Ebbor Gorge was visited. This is a well-worked site on the Carboniferous Limestone, now a National Trust Nature Reserve. Most of the more interesting calcicoles known from the Reserve were seen. These included Cololejeunea rosettiana, Marchesinia mackaii. Metzgeria conjugata, Isothecium striatulum, Grimmia orbicularis. Bryum canariense and Tortella nitida. Alan Crundwell spotted Zygodon baumgartneri on an ash tree and Jean Paton added Fossombronia pusilla and Dicranella rufescens to the list. Some people sought for Plagiochila britannica among the rich welter of bryophytes but without success. Several members were pleased to see Rhynchostegiella teesdalei in the small stream at the bottom of the Gorge.
After a climb through somewhat undistinguished woodland the party emerged rather dazedly onto the plateau above the Ebbor Rocks. Nothing of particular interest was found but it was generally felt that the magnificent view amply compensated for the lack of bryological entertainment.
Lunch was eaten in warm sunshine on the grassy verge of the car park. After this pleasant al fresco interlude a move was made to the vicinity of the area known locally as Priddy Pools, on the Old Red Sandstone. Soon after leaving the cars the attention of several of the party was attracted by a small moss growing on firmly compacted soil in company with Dicranella varia, Ceratodon purpureus and Barbula convoluta. It has since been found with fruit and appears to be closely related to Dicranella varia but has not been named. Leptodontium flexifolium was sought and found on a Calluna covered slope in its only known station in North Somerset. There was not time to visit the pools nor to go as far as the old lead mine about half a mile away but a small heap of lead mine waste was found on which Racomitrium lanuginosum and Grimmia donniana were seen. David Long was especially pleased to find Equisetum prothalli, of particular interest to Jeff Duckett who unfortunately was not present. Dr. Dennis Brown then took us over the road into a Forestry Commission plantation to demonstrate an area where the concentration of lead is so high+ that no trees can be persuaded to grow. The conditions are exactly those rejoiced in by Ditrichum plumbicola* which was found on this otherwise almost barren patch of soil.
I would like to thank those members who sent me lists of species seen during the day.
+ 31,000 to 51,000 ppm dry wt. of soil for Pb; 500 to 550 ppm for Zn.
* New vice county record.
J. Appleyard
Coupled with the Sunday field excursion, kindly summarized by Mrs. J. Appleyard, this was a successful and rewarding meeting. It could not have been so without the efforts of Dr. D. H. Brown and Mrs. Appleyard, who organized the indoor and outdoor activities respectively, and the Society must be very grateful to both.
M. E. Newton