The annual meeting was held on the weekend of 24-26 September in the School of Plant Biology, University College of North Wales, Bangor, by kind permission of Professor J. L. Harper. The meeting got off to a fine start on the evening of 24th with the special retirement dinner for Professor Paul Richards, C. B. E., an event which proved a delightful reunion for over 60 bryologists from all parts of the world. The highlight of the evening was an address by Professor Richards in which he reminisced on his 50-plus years as a bryologist. It was especially enchanting to hear, first hand, the now almost legendary tale of his visit, at the age of 12, to the distinguished Welsh bryologist, D. A. Jones. After recovering from the initial surprise that the new recruit to the art was a school-boy the latter kindly identified Paul’s mosses amongst which was Hedwigia integrifolia, appropriately later seen in the meeting’s excursion.
About 45 members and guests attended on Saturday when the President introduced 6 speakers, whose papers are summarized below.
Professor P. W. Richards (School of Plant Biology, Bangor): ‘Robert Hooke’s chapter on mosses’.
Robert Hooke’s Micrographia, published in 1665, records observations on a large variety of biological and other objects seen with the microscope developed and improved by himself. One chapter (‘Observation XXI’), headed ‘Of Moss and several other small vegetative substances’, is illustrated by an engraved plate with four figures showing the external features of the gametophyte and sporophyte (though not the gametangia) of a moss. The audience was invited to identify the species shown in Hooke’s plate. A wide variety of suggestions was made, but Prof. Richards own opinion was that if the figures were indeed all of the same species it could be Bryum capillare Hedw.
After a brief account of Hooke himself, the text of Observation XXI was discussed. It begins with a description of the morphology of the ‘common moss’ which includes such details as the filaments connecting the spore sac with the capsule wall. The language seems quaint, but it should be remembered that Hooke was handicapped by the lack of suitable descriptive terms and was ignorant of the life-history. He makes some shrewd observations on the physiology and ecology of mosses and gives an interesting discussion of whether moss ‘does sometimes originally spring or rise out of corruption’.
Hooke’s chapter is one of the most important early contributions to bryology and deserves much closer study than it has so far received.
Dr. L.B. Kass (Genetics Department, Cambridge University, and Cornell University, lthaca, New York, U. S. A.): ‘Chloroplast Replication in the moss Polytrichum’.
The chloroplasts of germinating spores of the moss Polytrichum replicate in darkness to a lesser extent than in light. After 48 hrs of darkness a stable mean number (plateau) of plastids per spore or germling is attained and exposure to light then stimulates the plastids to replicate. This light response appears to be phytochrome-mediated because when red light is used the promotive effect of the light can be completely reversed by far-red light. If the plastids at the plateau are given brief exposure to white light further replication of the plastids occurs in the light or in darkness. It appears therefore, that a response to light triggers a series of events that can continue in darkness. Cycloheximide (CHI) inhibits plastid replication completely, but chloramphenicol (CAP) inhibits only to the same extent as darkness. Neither inhibitor can stop the response of the plastids to light. Replication of plastids in spores that have been incubated in darkness for 48 hrs and transferred to light is prevented by both CHI and CAP but only for as long as the inhibitors are present. If CHI and CAP is washed out when the spores and sporelings are returned to darkness, plastid replication commences. It appears that the plastids exist in two phases with regard to replication: a light sensitive phase and a light insensitive phase.
Shalit (The role of light in the replication of plastids in a moss Polytrichum. Honours thesis, Cornell University, lthaca, New York, 1976), has recently shown that the effect of a 4 hr light exposure on plastid replication (as measured after 44 hrs of additional dark) can be reduced by 40% by 5 minute exposure to far-red light immediately following the white light treatment. However, if CHI is present during the light treatment, the effect of the light is negated completely by far-red light. It appears that the effect of light on plastid replication is mediated by a shift in the phytochrome balance (Pr/Pfr ratio). If protein synthesis is not allowed when the Pr/Pfr ratio is favourable, replication of plastids does not occur. Autoradiographic studies on nucleic acid synthesis in Polytrichum have indicated that light stimulates RNA and DNA synthesis as well as plastid replication. Nuclear and chloroplast DNA synthesis can be separated temporally, chloroplast DNA synthesis occurring before that in the nucleus.
Dr. T. G. A. Green and Dr. K. A. Clayton-Greene (Department of Botany, University of Waikato, Hamilton, New Zealand, and Department of Botany, University of Melbourne, Parkville, Victoria, Australia): ‘The Growth of Dawsonia superba Grev. ‘.
The growth (increase in length) of female plants without sporophytes of the giant moss Dawsonia superba was monitored for 450 days. Measurements were taken at about two weekly intervals by measuring increase in length from a marked point on the stem. Temperature, rainfall and humidity were also recorded at the site which was located in forest at 2280 feet on Mt. Te Aroha, North Island, New Zealand, latitude 37° 30′. S. Large differences in growth rates between plants were found, from 0 to 53 mm in 450 days. It was suggested that plants grew at between 30-50 mm per annum until archegonia matured when growth decreased. Growth was positively correlated with temperature (mean, P = 0.000003; maxima, P = 0.000003), day length (P = 0.004) and atmospheric water deficit (mean deficit, P = 0.001; mean maximum deficit, P = 0.00006). Growth was negatively correlated with rainfall (P = 0.02). Because these environmental factors are inter-related multiple regression analysis of growth on maximum temperature, day length, rainfall and mean maximum water deficit was carried out. By step-down predictive analysis the best predictor of growth was found to be temperature (P = 0.00006).
The apparent independence of the plant from rainfall was probably the result of the capacity of the plant to obtain soil moisture by its extensive rhizome system. The presence of wax on the apical cells of the leaf lamellae was demonstrated using a scanning electron microscope. It was proposed that the function of the wax was to act as a water repellent to prevent flooding of the interlamellar spaces with water.
Dr. G. A. M. Scott (Monash University, Clayton, Victoria, Australia): ‘Bryology in Australia’.
There are three phases in the history of Australasian bryology, those of: the explorers, the local field naturalists, and the professional bryologists.
- Explorers. Until roughly 1800, Australia and New Zealand shared the same bryological development. The earliest explorers, Tasman in N. Z. (1642) and Dampier in N. W. Australia (1699) collected no bryophytes. On Cook’s first voyage (1769) to New Zealand and Australia (with Parkinson as artist) Banks and Solander collected a few bryophyte specimens which probably were those used by Hedwig in his “Species Muscorum”. They are not in Hedwig’s herbarium and were presumably borrowed by him. Alternatively they may have been collected by the Forsters and Sparrman on Cook’s second voyage (1772) in the “Endeavour”, when Dusky Sound was first explored and surveyed. The first substantial collections of bryophytes, however, were made by Menzies in 1791 in Dusky Sound, on Vancouver’s “Discovery” expedition; many of the species were later described and illustrated in (3) W. J. Hooker’s “Musci Exotici”.
Other explorers followed in quick succession: 1792; D’Entrecasteauc in “Récherche” and “Espérance” visited Tasmania and West Australia, taking a botanist LaBillardière (4) who was probably the first to publish illustrations as well as descriptions of Australian bryophytes. 1800; Bauhin visited WA, NSW, and Tasmania with Leschenault as botanist. 1801-3; Flinders, in the “Investigator” visited the same regions with the great Robert Brown as botanist (and Bauer as artist); Brown collected a great many specimens including several bryophytes which, however, were never published. 1818; Captain King, with Alan Cunningham as naturalist, visited WA and Tasmania. 1819; Fréycinet, with Gaudichaud as botanist, visited NSW and Tasmania. 1840—41; J.D. Hooker, in the Antarctic Expedition, visited the Bay of Islands (N. Z.) where he collected many bryophytes with Dr. Sinclair and Colenso, a local naturalist; then on to the subantartic islands and Tasmania where he collected with Gunn, another local naturalist. 1847-9; Captain Stokes in “Acheron” surveyed the N. Z. coast, accompanied by Dr. Lyall who collected bryophytes assiduously; his results appear in (2) Hooker’s “Flora of New Zealand” (1867), which includes all plant groups and lasted as the standard reference work for the next century; indeed it is still the only flora for several plant groups. In Australia, botanists were less fortunate. In Tasmania, where terrain and bryophytes are similar to those of N. Z. and where Hooker collected extensively, his (1) “Flora Tasmaniae” (1859) was the precursor of several accounts of both mosses and liverworts, but the rest of Australia had to wait another century before (7) the first flora appeared (and that only for temperate region mosses), with a corresponding dampening effect on the development of Phase 2.
- Local Naturalists. This era lasted for approximately the next century (6). A dozen local naturalists of distinction carried on the bryological exploration of N. Z., of whom the two greatest characters were the Rev. Wm. Colenso (coll. c 1833-50 and 1870-99) and Robert Brown tertius (1824-96) both of whom published not wisely but too well. Work carried on into the 20th century, culminating in the era of Hodgson, Allison and Sainsbury whose (5) “Handbook of the N. Z. Mosses” (1955) effectively brought to an end the phase of the local naturalists (for mosses).
In Australia, during the same period, there were fewer collectors, but Ronald Gunn (coll. c 1832-70) in Tasmania, James Drummond in W. A. (Swan River Colony) (coll. c 1829-63) both collected extensively and sent very many specimens to the Hookers.
The emphasis on W. A. and Tasmania shifted to the south-east, to Victoria, with the advent of Baron Ferdinand von Mueller, who dominated Australian botany in the second half of the last century and sent thousands of bryophyte specimens to Kew and elsewhere (1849-97). The Rev. W. W. Watts, and others explored the moss flora of N. S. W. ; and Rodway and especially Weymouth, collected extensively in Tasmania about the turn of the century. There was then a considerable hiatus, with a brief revival of interest (8) in the 1950’s when J. H. Willis worked on Victorian mosses.
- Professional Bryologists. This is the era of the present day. With the untimely death, recently, of Bruce Hamlin, New Zealand has been deprived of a promising hepaticologist; and the still more recent death of K. W. Allison, the Grand Old Man of New Zealand bryology, marks the end of the Old Regime. There remain perhaps half a dozen bryologists in New Zealand, four of whom are professional botanists but none of whom seems likely to fill the role of taxonomic arbiter previously filled so ably by Sainsbury, Hodgson and Allison. In Australia, still well behind N. Z. in terms of knowledge of the flora, a similar handful of bryologists is at work – only one of whom is an amateur. Work is in progress on floras of the tropical mosses and of the liverworts, but it will be years before publication. The lack of a working handbook, which has hitherto handicapped bryological activity in Australia, has meant that many regions, especially alpine and tropical, are greatly under-collected, and this is a deficiency which cannot quickly be made good; but there are some signs of a revival of interest and the prospects for the future are bright.
|1||Hooker, J.D. (1855-9). Botany of the Antarctic Voyage. Part III. Flora Tasmaniae. Reeve, London (Including Mosses, 1859).|
|2||Hooker, J.D. (1867). Handbook of the New Zealand Flora. Vol. II. Reeve, London.|
|3||Hooker, W.J. (1318-20), Musci Exotici. 2 Vols. Longmans, London.|
|4||LaBillardière, J.J. (1806-7). Novae Hollandiae Plantarum Specimen. Huzard, Paris. Vol. II.|
|5||Sainsbury, G.O.K. (1955). A Handbook of the New Zealand Mosses. Bull. R. Soc. N.Z. No. 5. 490 pp.|
|6||Scott, G.A.M. (1971). New Zealand bryology; past, present and future. N.Z. Jl. Bot. 9: 739-43.|
|7||Scott, G.A.M., Stone, I.G., Rosser, C. (1976). The Mosses of Southern Australia. Academic Press, London.|
|8||Willis, J.H. (1955). The present position of muscology in Victoria. Muelleria 1: 55-59.|
Dr. S.W. Greene (Institute of Terrestrial Ecology, Penicuik, Midlothian): ‘The Species Problem in Bryophytes’.
The text of this paper is published in J. Hattori bot. Lab. 41, 1-6 (1976).
Dr. K. Lewis and Dr. A.J.E. Smith (School of Plant Biology, Bangor): ‘Bulbiferous Pohlias in Britain’.
This paper will shortly be published in J. Bryol.
Dr. P.D. Coker (Thames Polytechnic): ‘Microclimates, mosses and man; some views on rare and threatened species of bryophytes’.
It is well known that some species of bryophytes are endangered by over-collecting and such environmental factors as air pollution, but little is known about, and even less attention is paid to, the less immediately obvious causes of the decline or extinction of certain species. Changes in agricultural practice, building materials, drainage or forestry operations all cause problems as far as some of the more sensitive species are concerned. The possible effects of small changes in local weather patterns (micro-climate) are also considered, and some suggestions for active conservation of both species and habitats are made.
AGM and exhibitions
The Annual General Meeting was held after tea.
|In the evening members were generously provided with a splendid reception at Plas Gwyn, Hall of Residence, at which the following exhibits were displayed|
|Dr. H.L.K. WHITEHOUSE:||“Axenic cultures of bryophytes collected on the Knutsford meeting”|
|Mr. E.C. WALLACE :||“The ECW collection of photographs of bryologists”.|
|Dr. M.E. NEWTON :||“Heterochromatin and accessory chromosomes in hepatics”|
|Dr. M.C.F. PROCTOR :||“Scanning electron micrographs of peristomes”.|
The Society is very grateful to the University College of North Wales for making accommodation and lecture hall facilities available for its use. Indeed, the success of the meeting can be perhaps best measured by the fact that bryological activities did not cease until 3.30 a. m. on Saturday morning. At that time the Secretary was apprehended by the Gwynedd constabulary for driving the wrong way down Bangor High Street. He was, however, later discharged after explaining that he had got carried away in his endeavour to find Bryum radiculosum on the walls of the cathedral.
On 26 September, in brilliant autumn sunshine, members set out to explore Craig-y-Dulyn, a cwm on the eastern side of the Carneddau range, previously little known bryologically. Members spread out like sheep over the hillside and recorded over 170 species. Blanket bogs produced 17 Sphagna including S. contortum, S. girgensohnii, S. robustum, S. warnstorfianum, S. teres, S. flexuosum var. tenue*, and several others with antheridial branches in the peak of condition, a characteristic autumnal feature of the genus in Britain. In the flushes were Acrocladium sarmentosum, Pellia neesiana and Scapania uliginosa in only its 4th Welsh locality. Diverse habitats about the cliffs, including large areas of basic ground, provided a wealth of uncommon mountain species, most notably Amphidium lapponicum, Barbula ferruginascens, Bartramia ithyphylla, Blindia acuta, Dicranella subulata, Fissidens osmundoides, Grimmia funalis, G. stricta, G. torquata, Pterogonium gracile, Rhabdoweisia crenulata, Rhacomitrium ellipticum, Anastrepta orcadensis, Douinia ovata, Gymnomitrion concinnatum, Herberta adunca, H. straminea, Hygrobiella laxifolia and Leiocolea muelleri. On the screes were Antitrichia curtipendula, Scapania scandica, Marsupella ustulata, Barbilophozia barbata, B. atlantica and fine Tetraplodon mnioides, the last a sombre testimony to multiple ovine suicides from the cliffs above.
[* New vice-county record.]
Later in the day one party visited the River Conwy near Trefriw to collect Fissidens monguillonii only to be thwarted by heavy overnight rain which had submerged the plant under several feet of water. Brian O’Shea was only restrained from swimming for the Fissidens by abundant Orthotrichum sprucei on riverside alders, (i.e. he nearly fell in). The excursion did, however, finish on a successful note with a pilgrimage to see Ditrichum plumicola together with Weissia controversa var. densifolia and Cephaloziella hampeana at Pen-yr-Allt mine near Llyn Crafnant. The meeting finally concluded with a soireé at the author’s house, but alas it was too dark to see Fissidens celticus and Pohlia lutescens in the garden.