The role of botany in the development of the Republic of South Africa with special emphasis on the contributions of the Botanical Research Institute

Five papers cover different aspects of the contributions to and role of botany in the development of the Republic of South Africa. Two papers sum up the contributions for the non-agricultural and agricultural sectors. The introductory paper by D. J. B. Killick provides a short historical account of the Botanical Research Institute, followed by a discussion of the contributions of the Institute to botany in South Africa through its National Herbarium and identification service as well as researches in taxonomy, plant anatomy, cyto-genetics, ecology, economic botany and data processing. B. de Winter emphasizes the fundamental role of taxonomy and bio-systematics for planning and the optimal use of the natural plant resources. The current support for taxonomy and biosystematics is examined and proposals made for improving progress in the Flora of Southern Africa series. For plant physiology, N. Grobbelaar discusses, firstly, the ways whereby the productivity of a plant species with its characteristic genetic constitution can be raised by determining and modifying for optimal response the effects of environmental factors such as spacing, mineral nutrition, water provision, etc.; and, secondly, usually when the first means has been achieved, of improving plant productivity by altering the genetic constitution of the plant so that it can perform better than its ancestors under the prevailing conditions. After discussing and illustrating the applications and roles of plant ecology, D. Edwards concludes that basic plant ecological research is required, firstly, at the regional level through regional plant ecological studies to supply the essential local knowledge needed by researchers, planners and users of the land; and, secondly, at the more detailed level where knowledge is needed of the processes and factors that govern the behaviour of vegetation so that it can be properly used, managed and manipulated. M. J. Wells discusses the role of economic botanists for priority research assessment, and for research on problem plants, such as weeds, and on plants for food and other useful products, especially from the rich and untapped South African flora of over 17 000 species. The needs for an adequate base of primary botanical data are stressed, and for ethnobotanical work to assist exploration of plant uses. S. A. Hulme, in his summing up for the agricultural sector, points out that despite the emergence of the specialist agricultural disciplines, botanical research remains fundamental to the understanding of the plant. Following on the important contributions that botany has made to agriculture, there remain many important contributions to agriculture for the future through physiological and other botanical studies. In his summing up for the non-agricultural sector, D. M. Joubert illustrates the ways whereby the influence of the Botanical Research Institute and its co-operation with other institutes and organizations extends beyond the purely agricultural field to other national programmes involving terrestrial and inland water ecosystems, in plant alkaloid research, in nature conservation, etc.

medium chiefly for taxonomic papers and the Flower ing Plants of Africa, an illustrated serial much on the lines of the well-known Curtis's Botanical Magazine.
The first wing of a new herbarium, of which Dr E. P. Phillips was curator, was opened in 1923 by General J. C. Smuts.About this time a valuable link with European botany was established when a post of liaison officer at the Herbarium of the Royal Botanic Gardens, Kew, was created.
Under the energetic leadership of Pole Evans, the Division expanded rapidly.A plant physiology unit was started at Fauresmith Veld Reserve under Dr Marguerite Henrici, the Natal Herbarium was acquired and the maintenance of the museum her baria in Grahamstown and Kimberley were agreed to.Thus, regional herbaria came into being.The National Herbarium meanwhile benefited from the incorpora tion of the important collections of Galpin, Marloth, Pegler, Flanagan, Dieterlen, Thode and others.
Eventually a Division of Plant Industry was formed, comprising the sections botany, plant pathology, horticulture, entomology, field husbandry and pasture research.It is difficult to believe that much of what is to-day the Department of Agricultural Technical Services was once a single Division under the direc tion of a botanist!However, when Pole Evans re tired in 1939 the sections again became separate divisions with Dr E. P. Phillips as head of the Division of Botany and Plant Pathology.
Dr R. A. Dyer succeeded Dr Phillips in 1944 and, after relative dormancy during World War II, de velopment again proceeded apace.Negotiations with the Faculty of Agriculture of the University of Pre toria led to the establishment of the Pretoria National Botanic Garden.In 1956 the Trustees of the Transvaal Museum donated the valuable Museum herbarium to the Division.In the same year, with the final retirement of Dr Henrici, physiological work at Fauresmith ceased and the Veld Reserve was trans ferred to the O.F.S. Region.Similarly, the Veld Reserve at Worcester, where Karoo fodder plants were studied, passed to the Winter Rainfall Region.
Changes in the name of the Division occurred from time to time.In 1953 Plant Pathology hived off, leaving Botany on its own.In 1961, with the re organization of the Department, the Division was renamed the Botanical Research Institute.About the same time the herbarium of the University of Stel lenbosch's Botany Department was added to the regional herbaria of the Institute.In 1963 Dr L. E. Codd became director of the Institute.
Following a full-scale Public Service Commission inspection in 1966, additional posts were allocated to the Institute and four sections were recognized, namely the Herbarium Service and Information Section, a separate Flora Research Section, the Botanical Survey Section and the Economic Botany Section.Continued progress followed culminating in the opening of this building in July 1973.A few months later, Dr Codd retired and was succeeded by the present Director, Dr B. de Winter.A fifth section, the Data Processing Section, was created in 1976.This, then, is the history of the Institute in broad out line.Now we can consider the contributions made by the Institute to botany in South Africa.First of all, let us consider the National Herbarium, Pretoria, and the regional herbaria.The National Herbarium, with its c. 500 000 specimens is the main repository for plant specimens in the Republic.It, together with the regional herbaria, identifies some 32 000 speci mens annually for a variety of institutions etc., for example Onderstepoort, the Agricultural Regions, our own Botanical Survey Section, the Forestry Department, the Provincial Nature Conservation departments, the universities, farmers and the general public, as well as institutions in neighbouring coun tries such as Swaziland, Lesotho and Botswana.It is clear that a considerable number of research pro jects in southern Africa have relied and are relying heavily on the identification services provided by the Institute.Let me cite a few examples: nearly all the identifications for Dr A. Jacot Guillarmod's Flora of Lesotho were done by the National Herbarium; similarly, Professor Compton's Check-list of Swazi land, Palmer & Pitman's Trees of Southern Africa, Professor van der Schijff's survey of the Kruger National Park and Professor N. Grobbelaar's study of nitrogen-fixing plants.I wonder whether we fully appreciate this identification service; it is a facility not enjoyed in many countries.
Herbaria do not just grow and expand without deliberate input of specimens.Apart from the speci mens gained from ecological surveys, the Institute has undertaken numerous collecting expeditions all over the Republic, South West Africa, Lesotho and even as far north as Kenya.The East African expedition was undertaken in 1938 by Pole Evans, an ardent collector and skilled photographer of vegetation.
Closely linked with the herbarium is taxonomic research: the herbarium houses the specimens studied by the taxonomist.A list of some of the taxa revised by taxonomists of the Botanical Research Institute will give some idea of the contributions to botany in this field: the Stapelieae, succulent Euphorbieae, Encephalartos and Cyrtanthus by Dr R. A. Dyer, Gladiolus (with Dr G. J. Lewis) and Ornithogalum by Mrs A. A. Mauve, Kniphofia and Plectranthus by Dr L. E. Codd, Zantedeschia by Dr C. Forssman, Crinum by Dr I. C. Verdoorn, Aristida, Stipagrostis and Eragrostis by Dr B. de Winter, the African species of Acacia by Dr J. H. Ross, and Crassula by Dr H. R. Tolken.In addition, there is the considerable research that has gone into the preparation of the several volumes of the Flora of Southern Africa, the two editions of Phillips's Genera and the first edition of Dyer's Genera.We are indeed fortunate to have an up-to-date Genera and an ongoing Flora.I do not wish to "knock" Australia, but that country has neither a Genera nor a recent Flora in spite of being blessed with nearly 100 plant taxonomists.An ex tremely important contribution to botany and agri culture in South Africa was Lucy Chippindall's "Guide to the identification of the grasses" in the "Grasses and pastures of South Africa" (1955).
So far I have only spoken of flowering plant taxonomy, but in years gone by the Institute has also accomplished much in mycology, for example the revisions of fungi by Dr E. M. Doidge (author of the monumental, 1004-page " South African fungi and lichens to the end of 1945"), Miss A. M. Bottomley, Dr P. H. B. Talbot and their successors.
Associated with taxonomic research is the Ana tomy and Cyto-genetics Laboratory.Although only 10 years old, it has already proved its worth.The survey of the leaf and embryo anatomy of the South African grasses, with its standardized descriptive schedules and computer linkage, is a model piece of research, which is yielding interesting results and will undoubtedly assist in taxonomic studies of the grasses.The cyto-genetic studies of the Eragrostis curvula complex, Lantana camara, Opuntia aurantiaca etc. are similarly yielding useful results.
The Botanical Survey Section of the Institute has contributed many important surveys of vegetation in this country.A look at the 42 Memoirs of the Botanic al Survey of South Africa (mostly ecological) publish ed by the Institute will give one a good idea of the scope and quality of the surveys carried out.One immediately thinks of the surveys of Albany, Keiskammahoek, the southern Kalahari, the Tugela Basin, the Cathedral Peak area of the Natal Drakensberg, to name only a few.However, undoubtedly the most significant survey undertaken was Acocks's "Veld Types".The resultant memoir, together with the vegetation map, has proved to be a classic work much quoted by scientists of many disciplines.The particu lar virtue of the map is that besides being a vegetation map, it is also a land-use map.It is true to say, I think, that very few countries possess a comparable map, and I believe that the U.S.A.only recently decided to produce such a map.
The Institute has frequently taken the lead in quantitative ecology in the Republic: first of all by applying association analysis, then ordination, and finally the Braun-Blanquet method.To gain expertise in the Braun-Blanquet method the Institute imported two specialists from the Netherlands, Dr M. .J Werger and Mr F. van der Meulen, and the result is that the method has become standard practice in the survey repertoire of the Botanical Survey Section.By means of workshops the method has been intro duced to other institutions.
The Botanical Survey Section is intimately involved in the South African Savanna Ecosystem Project at Nylsvley and in various conservation projects, e.g. the survey by Dr D. Edwards to determine the adequacy of conserved areas in relation to vegetation types, and the survey of the Zululand coastal dunes by Dr P. Weisser to establish conservation priorities as the result of dune mining.
The Economic Botany Section is a comparatively new section of the Institute, but many of its functions have been carried out from the very beginning of the Institute.You will remember that in the account of the history of the Institute, I mentioned that among Burtt Davy's duties was a study of forage plants, poisonous plants and weeds.The Institute has played its part in the introduction of pasture plants, e.g.kikuyu (Pennisetum clandestinum), teff {Eragrostis abyssinica), Sudan grass {Sorghum sudanense), Napier fodder {Pennisetum purpureum), Nile grass {Acroceras macrum) and Cocksfoot {Dactylis glomerata), to name only a few.As regards poisonous plants, we have always co-operated successfully with the The Data Processing Section is the youngest section of the Institute.Its main task to date has been the computerization of the National Herbarium.All 500 000 specimens have been encoded and processed, and programmes for the retrieval of herbarium infor mation are nearing completion.In computerizing the National Herbarium, the Institute has achieved a first in South Africa, and a first in the world for large herbaria.
Mention must be made of the Mary Gunn Library.In building up what is virtually a national botanical library, the Institute has provided South African botany with a priceless asset-one that is used by botanists all over the country and even across our borders.Credit for this library must largely go to Miss Gunn who, by perseverance and persuasion, built up the library from scratch.
Since 1926 the Institute has had a Liaison Officer at Kew.This has proved invaluable to the Institute and South African botany.Six of our staff here to-day, including the Director and one past director, have had spells at Kew and profited immensely from the ex perience.Apart from the training received and con tacts made with European botanists, the liaison officers have solved many taxonomic and nomenclatural problems submitted to them by the Institute and universities.
The Pretoria National Botanic Garden is a garden with a difference.Catering for only indigenous plants, it provides research workers with study material, it serves as a plant introduction centre, and at the same time it provides the public with an attractive recrea tional and educational amenity.ecology in South Africa has been published in these works.For an Institute of our size to publish two journals with an international reputation, a prestige serial and a Flora is an achievement.Besides its own publications, the Institute has contributed substan tially to a number of authoritative botanical and related works, for example "Wild Flowers of the Transvaal" (Letty), "Trees of Southern Africa" (Palmer & Pitman), " Ericas in Southern Africa" (Baker & Oliver) "Aloes of South Africa" (Reynolds), " Grasses and pastures of South Africa" (Meredith), "The medicinal and poisonous plants of Southern Africa" (Watt & Breyer-Brandwijk), several books on South African wild flowers and gardening by Sima Eliovson and the recently-published " Biogeography and ecology of Southern Africa" (ed.Werger).
In conclusion, may I say that it has been impossible in the time at my disposal to describe all the contri butions of the Botanical Research Institute, but I hope that what I have said will have convinced you that the Institute's contributions to South African botany have been considerable.In fact, ladies and gentlemen, I would go so far as to suggest, in all modesty, that the Institute's contributions have constituted the major part of South African botany in the fields mentioned.We shall continue to achieve
Heelwat gepubliseerde navorsingsresultate oor plan te is verder nie die papier werd waarop hulle gedruk is nie, omdat hulle nie deur verwysingseksemplare gerugstaaf is nie.Selfs onder wetenskaplikes bestaan dus 'n gebrek aan kennis en insig oor die rol en belangrikheid van plantsistematiek, en is dit waarskynlik deels hieraan te wyte dat in Suid-Afrika onvoldoende ondersteuning vir die taksonomie gegee word.In kontras hiermee is daar 'n toenemende wercldvye besef van die uiters waardevolle bydrae en fundamen tele belangrikheid van hierdie wetenskap.Dit blyk uit, onder andere, die resolusies wat deur twee onlangse internasionale kongresse aan die regerings van alle lande van die wereld gerig was.Ek haal enkele frases aan uit die resolusies van die IUBS Kongres, gehou in Noorwee in 1973 en bevestig op die Internasionale Botaniese Kongres in Leningrad in 1975.Hulle Iui soos volg: " The International Union of Biological Sciences, Recognising that the future of mankind depends on the treatment given to natural resources and that a rich variety of living organisms is a fundamental part thereof, Recognising that our present knowledge is very de ficient and that in most biological disciplines, and especially in ecology, a proper knowledge of the systematics of the investigated organisms is of de cisive importance, Realising that the biotica of many countries are still imperfectly known, that taxonomic handbooks are lacking for many organisms and areas, and that competent taxonomists are too few to cope with all the material that requires determination, Urges all governments, especially those providing technical assistance to developing countries, to strengthen taxonomy and especially taxonomic in frastructure required for training taxonomists and for making the ecological studies necessary to facili tate improvements in the use of resources and the effectiveness of technical development." Hierdie resolusies is vandag reeds oorbekend.Nogtans is sedert 1973 min vordering gemaak met die regstelling van die leemtes in ons organisasies en ons is nie in 'n veel sterker posisie om die taksonomiese probleme die hoof te bied as vyf jaar gelede nie.
Die beroemde Duitse wetenskaplike Justus Liebig het reeds in 1840 by die Britte gekla dat plantkundiges nie genoeg aandag aan die chemiese en fisiese aspekte van plante bestee nie.Hy het die haglike posisie onder andere toegeskryf aan die feit dat, soos hy dit gestel het:in Botany, the talent and labour of inquirers has been wholly spent in the examination of form and structure; chemistry and physics have not been allowed to sit in council upon the explanation of the most simple processes; their experience and their laws have not been employed, though they afford the most powerful means of help in the acquirement of true knowledge.They have not been used because their study has been neglected.All discoveries in physics and in chemistry, all explanations of chemists, must remain without fruit and useless, because, even to the great leaders in botany, carbonic acid, ammonia, acids, and bases, are sounds without meaning, words without sense, terms of an unknown language, which awaken no thoughts and no associations.They treat these sciences like the vulgar, who despise a foreign literature in exact proportion to their ignorance of it; since even when they have had some acqaintance with them, they have not understood their spirit and application." Mnr die Voorsitter, dit is 'n kwaai aanklag maar gelukkig is dit darem nie werklik vandag meer geldig nie.Soos u weet is dit onredelik om te verwag dat die Instituut met sy beperkte mannekrag aan alle vertakkings van die plantkunde reg moet laat geskied en ons weet dat sy onaktiwiteit in die plantfisiologie nie werklik te wyte is aan onverskilligheid teenoor hierdie faset van die plantkunde nie.Die miskenning van die plantfisiologie binne die Navorsingsinstituut vir Plantkunde geniet op die oomblik die ernstige aandag van 'n Advieskomitee wat sy edele, die Minister van Landbou in die lewe geroep het.Moontlik lei die handelinge van daardie komitee nog tot die stigting van 'n nasionale laboratorium vir plantfisiologie binne die Navorsingsinstituut vir Plantkunde.Vorm en funksie vorm so 'n onvervreembare eenheid dat diegene wat dit bestudeer, slegs kan baat deur 'n intieme assosiasie met mekaar.
Naas water, is stikstof seker die algemeenste be perkende faktor in die produktiwiteit van plante in Suid-Afrika.

D. EDWARDS*
In straightforward terms, plant ecology is concerned firstly with describing, measuring and classifying the structure of vegetation: how its constituent plant communities are made up and organized and can be classified, which are necessary first steps in their study; and, secondly, with studying the processes that account for how vegetation behaves, why it is there in accordance with particular sets of physical and animal environmental factors, including mancontrolled influences.As a biological field of study it draws from other biological and physical disciplines, such as plant physiology and taxonomy, mathematics and soil science, but it has also developed its own unique concepts, principles and methodology.
In relation to its role in the development of South Africa, it will be apparent that plant ecology is really concerned with two aspects: firstly, with analysing and assessing vegetation, as a resource amongst which animals and human populations exist and without which they cannot exist; and secondly, by explaining how that vegetation exists under different kinds of natural and man-controlled environment, can be ascertained how it will react to and can be manipulated for human needs.Plant ecology thus has a basic role for the assessment, planned use and management of the natural vegetation resources of the country.It will be obvious, too, that use of vegetation, as well as of other resources, cannot be seen without reference to the use of the other natural resources of the country, so that integrated, planned use of the national resources is necessary.As ex pressed by Walker (1977), "The objective of integrated resource planning is the optimum use of natural resources for the maximum benefit of the population.This implies taking into account all of the require ments people may have for these resources, and trading off contribution to the Gross National Product against legitimate demands for recreational facilities and for reserve supplies for future commodity needs."Though not a new idea, ecological principles should play an important part in land use planning, and in predicting and assessing the consequences of various forms of resource use and human activity.Africa.In an ecological sense, landscapes have chang ed from the natural to the semi-natural and sub natural, and ultimately to the cultivated and urban where human influences and structures are dominant.That these changes will continue to occur at an even faster rate is clear from population estimates for the future.These indicate a doubling of the present population of some 25 million by the end of the century, with projections of more than 80 million people by the year 2020.Not only will this 2,6% annual increase in population represent an increase in the number of persons requiring more food, ser vices, facilities, products, housing, space, etc., but an increased demand also because the anticipated rise in the average standard of living will mean even greater demands for food and the rational planned use of land and natural resources.Of the vast area of some 103 million ha available for farming, about two thirds, representing 55,5% of South Africa, has a mean annual rainfall of less than 500 mm.Agricultural intensification is thus limited by a low rainfall and the natural grazing provided by the indigenous vegetation is the major farming asset.However, it is also in these dry regions that the deterioration of vegetation and soils has been most widespread, resulting in desert and Karoo encroachment.While research to raise agricultural production is rightly being concentrated on areas with an inherently high agricultural potential, long term planning for optimum land use, increased pro duction and reclamation of the drier regions cannot be ignored.
For the remaining one third of the land available for agriculture where the mean annual rainfall is higher than 500 mm, here, too, the natural vegetation has a role in farming since only some 15% of the land available to agriculture is estimated to be suit able for cultivation.
The conclusion to be drawn from the current land use data is thus that for natural pastures and nature reserves, amounting to 71% or 87 million ha of South Africa, the natural vegetation is the primary biological resource.To this should also be added a not inconsiderable amount of natural vegetation that needs to be managed for a variety of purposes, such as roads, railways and airport reserves, various state lands and miscellaneous areas.These amount to an additional nearly 10%, or 13,1 million ha of South Africa.The natural vegetation is thus currently a major asset, requiring planned national use and for something like 80% at least of the surface of South Africa.
If one looks at future trends in land use, it is clear that while the area covered by natural vegetation may be expected to decrease, for over 55,5% at least of South Africa (67,7 million ha) the natural vegetation will still be the main agricultural resource because of climatic and other limitations, to which must also be added other unintensified agricultural land, nature reserves, road, railway and airport reserves (which can be expected to increase in amount), as well as mis cellaneous other areas.It would seem not unreason able to expect that between 55-65% of South Af rica's natural vegetation will still, in the foreseeable fjture, provide an important source of agricultural produce, provide recreation and conservation environments, and provide the cheapest means of conserving soil and water.But an increase in population accompanied by technological innovation, the growth of urban complexes, and the intensified use of land will, as has been amply demonstrated during the past few decades, bring new problems for the maintenance of a stable and satisfactory human environment.Many of these problems can be anticipated and will need to be resolved by the application of ecological principles.
Because extensive pastoral farming obviously de pends on the natural vegetation, much of the stimulus to early plant ecology in South Africa was provided by the need for basic ecological knowledge.The developing agricultural industry required knowledge of local ecological conditions and there were obvious problems arising from the use of the veld by the farmers.Naturally, there was also a strong scientific interest in the unique vegetation and flora.It was thus logical that in 1918 the South African govern ment decided to appoint a Botanical Survey Ad visory Committee, the majority of whose functions were to carry out basic and applied plant ecological research.In passing, it is refreshing to recall now adays the comment in the Kew Bulletin of 1919 on "The enlightenment of outlook in matters connected with the bearing of scientific knowledge on practia 1 affairs which experience has taught us to expect on the part of the Government of the Union of South Africa . .." .
The appointment of the Botanical Survey Advisory Committee was followed in 1925 by the appointment of the first Botanical Survey Officer ard by the creation in 1945 of an additional three posts for a small Botanical Survey Section specifically for basic plant ecological research in the Division of Botany and Plant Pathology, predecessor to the present Botanical Research Institute.By this time the more specialized applied plant ecology concerned with what is now called pasture management was being actively developed by men such as Scott, Tidmarsh and West, who had originally been trained as botanists.Pasture management had become separated at university faculties and w;thin the Department of Agricultural Technical Services.This pasture management research had expanded to the extent that in terms of personnel it exceeded basic plant ecological research.In this paper I would like to concentrate upon the role of basic plant ecology, rather than upon pasture manage ment which has perhaps more clearly defined ob jectives and applications.
As set out in 14 points the aims and scope of the Botanical Survey Advisory Committee were remark ably clear and farsighted, reflecting the development of basic and applied plant ecology in South Africa and even the future organization of the present Depart ment of Agricultural Technical Services.
The more specific plant ecological objectives agreed upon by the 1918 Botanical Survey Advisory Com mittee were: (i) "To continue and extend the survey and syste matic work already carried out.
(ii) "To continue and extend the work already ac complished by the Forest Department in further ascertaining the composition of the indigenous forests, the nature of their products and their industrial possibilities".
(iii) "To study the vegetation from an industrial point of view", which had implications for both ap plied plant ecology ^.nd economic botany.
(iv) "To study the plant succession under natural and artificial conditions" .
(v) "To study the vegetation of the veld in connec tion with its feeding value and carrying capacity and to distinguish botanically between 'sour' and 'sweet' velds, good and bad pastures" .
(vi) "To study the disturbing influence of burning, mowing, cultivation, drainage, irrigation, overstock ing, insect and pest plants on the natural vegetation".
(vii) "To devote more attention to the soil and its micro-organisms", which anticipated the present Soils and Irrigation Research Institute and soil micro biological studies, and also the need for work on plant-soil interrelationships by plant ecologists and plant physiologists.
Following the establishment of the Botanical Survey of South Africa, basic plant ecological re search has tended to concentrate on regional ecological studies.The early general accounts of the vegetation of South Africa by Bews, Pole Evans, Adamson, culminated in the now standard work on the Veld Types of South Africa by Acocks (1975), in which he recognized some 70 veld types and 70 variations.In detail and accuracy his 1: 1 500 000 map was unique amongst national vegetation maps.Numerous regional studies were also carried out, the history of which is very largely reflected in the 42 volumes of the Botanical Survey Memoir series.Chiefly in the post war era, quantitative methods were applied to the measure ment, classification and evaluation of vegetation.The use of computers and air photography has become standard practice, and satellite imagery has been investigated for its use in vegetation study and inventory, and for the regional assessment ecological factors such as fire.In the post war era there has also been an important endeavour to improve and stan dardise methods for efficiently classifying vegetation in a system that allows for prediction and extrapola tion for subsequent study and for planning and management.
The main objectives of these regional studies have thus been to classify the various kinds of plant com munity and to establish their climatic soil and biotic relationships, as well as to ascertain the main func tional processes, such as plant successional trends, and retrogressions leading to climax, sub-climax and disturbance kinds of vegetation.These studies sup plied the basic knowledge needed to define the real problems requiring further basic and applied research on veld use, and provided assessments of the quality and kinds of vegetation resource upon which agri cultural planning could be based.
In terms of the costs of such research it is worth while pointing out that such regional ecological studies, or surveys as they are commonly known, must surely rank as one of the cheapest forms of research.The application of cost-benefit analyses to such regional studies is difficult, however, because they serve an exceedingly wide range of direct and indirect interests for the current as well as the long term periods of time.At best, an indication only can be given here of the role of such studies.They can be briefly illustrated for: (i) Vegetation resource evaluation and planning.
(ii) Vegetation resource use and management, and (iii) Research planning.
Vegetation resource evaluation and planning is done at two levels in agriculture: at farm planning level and at regional level.For farm planninggrazing camps, allocation of watering points, etc.ecological sub-divisions reflecting grazing potential and management needs have to be compatible with practical considerations such as fencing costs and overall farming objectives.Regional plant ecological studies showing the species content of plant communi ties, plant successional relationships, retrogressions and environmental indicators assist the agricultural extension officer and farmer to attain optimum land use potential by specifying what he has to farm and the farm's potential.Furthermore, by knowing and having classified the vegetation, intelligent extra polation of the results of detailed grazing experimental work at agricultural research stations and from co operative research projects on other farms, is possible.It is an important fact that regional plant ecological studies are currently lagging far behind because of the limited manpower and post allocation for such work.This has often resulted in the quite understandable but actual misapplication of broad scale ecological results from a national vegetation map such as Acocks to local farm planning.
At the regional planning level, regional plant ecological studies have assisted in locating agricul tural research stations and in defining areas of high and low agricultural potential.Assessments have thus been possible for planning the many aspects of the agricultural industry.
For nature conservation, use of the national Veld Types map has been used to show areas requiring conservation-where ecosystems and gene pools of species are likely to disappear and which areas can serve as base line areas for future monitoring with respect to surrounding land use.Particularly striking, for example, was the fact that in 1974, 42 of South Africa's 70 Veld Types had none or virtually no permanent conservation areas (Edwards, 1974).Planning of future nature conservation and recreation areas could thus be placed upon a more logical basis than before because of the national vegetation map.At local levels, the knowledge from regional plant ecological studies has assisted in road planning by indicating vegetation that should be conserved, as against that which is adequately conserved and not worth conserving.Regional planners have found that plant ecological studies can supply basic information relevant to development schemes, such as in the Saldanha Bay, Pretoria-Witwatersrand-Vereeniging com plex, Eastern Transvaal, Natal and other areas.The allocation of roads and other development schemes can thus be undertaken without major conflict to environmentalists and to ecological principles obvious to an ecologist but not always to the non-ecologist.
For vegetation resource use and management, regional plant-ecological studies have, as already pointed out, served the farmer directly in farm management.Some of the most striking examples of the consequences of the misuse of land were defined by Acocks (1975).He described and mapped the second ary or False Karoo replacement of grassland for an area of 10% or 12 million ha of South Africa.Areawise, however, the conversion of extensive areas of grassland into less productive Karoo is far less than the deterioration of the Karoo itself, which covers nearly a third of South Africa, where the grass com ponent has suffered more than in any other vegetation type in South Africa.
Plant ecologists have been amongst the first to point out other vegetational resource problems, such as the invasion of alien plants into the natural vegeta tion, and the increase of weedy and poisonous in digenous plants resulting from use of the veld.Attention has been focussed, too, upon aquatic weeds, which increase evapo-transpiration and im pede recreational, agricultural and other use of dams and rivers.
Discerning the role of fire, the relationships to soil and climate and the effect of grazing and other forms of land use on the vegetation are an inherent part of regional plant ecological studies, which ex plain or at least present hypotheses to account for the different kinds of natural and man-induced plant community.Although the scientific method dictates that observations and hypotheses of cause and effect relationships should be subjected to the test of experi ment, such experimentation needs intelligent planning for worthwhile objectives on a priority basis.Regional plant ecological studies thus provide information necessary to assess research priorities and the form that such research should take.For example, for the South African Savanna Ecosystem project at Nylsvley it may be argued on logical and legitimate grounds that in terms of extent, utilization problems and inherent potential, the savanna type ecosystem re quires intensive study to elucidate the fundamental ecological processes governing that kind of ecosystem.Furthermore, since such multi-disciplinary research is expensive, it obviously requires careful planning and justification.Equally important too, is that proper extrapolation of the Nylsvley Project results will depend on the classification of vegetation resulting from regional ecological studies.
Although South African plant ecology has in the past been much concerned with the primary task of describing and assessing the nature of our vegetation, its ecological behaviour and characteristics, there has also been considerable research on autecological, eco-physiological and other studies of the basic processes that govern the behaviour of plant com munities.One of the most remarkable series of studies was undoubtedly that carried out on ecophysiology by Dr Marguerite Henrici between 1922 and 1958.In over 70 scientific publications she examined a range of problems connected with agri culture, such as phosphorous deficiency and the water requirements of the natural veld.Other plant ecologists and pasture research workers have carried out experimental work to ascertain the effects of different kinds of burning, mowing and grazing management treatments of the veld.
As farming becomes more intensive and the overall pattern of land use also becomes more intense, the need increases for more exact information on the ecological processes regulating the behaviour of vegetation.The need for basic research is becoming more and more urgent on the eco-physiological processes regulating the behaviour of ecological systems, and for the ecologically important plants, weeds, rare and threatened species that make up these ecosystems.A consideration of the weed problem alone, that costs many millions of rands for their direct control, and many millions of rands for lost production from crops and livestock, indicates the justification for such re search.Current work being carried out by this and other institutes on the growth and productivity of trees and grasses in the bushveld is leading to an understanding of the grass-tree relationship.Ulti mately, better understanding of the scrub encroach ment problem in South Africa will permit better and sustained use of the savanna type vegetation that covers about one third of the country.
Outside the field of agriculture, it is clear that there is developing a need for a new breed of ecologist, the applied ecologist, whose task is to manage and supply advice to other managers on how to maintain and regulate the various facets of the human environment.The management of areas such as marinas, water and terrestrial areas belonging to municipalities, game farms, etc., require trained ecological personnel.What is more, however, these applied ecologists will need an adequate background of basic local i.e.South African ecological research data to enable them to carry out their tasks.It seems more than likely too, as has happened in the United States, that construction and development agencies will require trained ecolo gists to assess the environmental impact of develop ment schemes.Government departments, the biggest employers of ecologists, at present have the services of ecologists, but to avoid carrying out advisory applied ecology work at the expense of their primary function as basic researchers, specialization amongst ecologists is becoming necessary.Research institutes at which there is a group of plant ecologists are in the fortunate position that when sufficient posts are available, the applied and advisory type ecologist has a background of basic research upon which he can call.Further more, by the feed-back process, much of the basic research needed can be appropriately problem orientated.The critical problem at present is the lack of sufficient posts to carry out the basic plant ecologic al programmes needed for the future and to provide for a body of applied advisory and management type plant ecologists.
To summarize and conclude, basic research is need ed to satisfy a wide range of user requirements, now and for the future.This research is needed at two levels: (a) At the regional level through regional plant ecological studies to supply the essential local infor mation sorely needed by planners and users of the land, and for (b) Research at the more detailed level where fundamental knowledge is needed of the processes that govern the behaviour of vegetation, so that it can be properly used, managed and manipulated for the common good.
Finally, the necessity for the translation of research data into practical terms for the user requires a special class of practical ecologist, who can ensure that plant ecology plays its role in ensuring the wise use of land in the future development of South Africa.

The role of economic botany in the development of South Africa
M. J. WELLS* Botany should be seen not merely as the study of plants, but as the study of one of mankind's basic natural resources.It is the business of economic botany to increase the material benefits that man receives from plants, remembering not only man's need for foods, but also man's need for an environ ment with green growing things.Unfortunately, we are dealing not only with animal man and cognitive man, but also with unreasonable man, who wants to be free to breed and yet expects the quality of life never to diminish for himself and his children.For this reason good botanical economics will increasingly mean a good balance between plant utilization and conservation.Economic botanists have a definite role to play not only in utilization, but also in con servation: in respecting the conservation status of the plants that they seek to utilize; by giving tangible economic values to the indigenous flora; and by contributing to the control of weeds that threaten the flora.
If primary botanical data are lacking, then the role that the economic botanist can play is seriously restricted.At present, the main lack of basic informa tion is: lack of information on the genetic make-up of problem taxa; the lack of, and patchiness of, distribution records for all plant species, but particu larly for weeds; and the lack of a detailed or semi detailed vegetation map-coverage of the country as a whole.
If economic botanists have to collect this informa tion for themselves, or do without it, their effective ness will be greatly reduced.For example, without a detailed vegetation map it will be difficult to relate economic species and groups of species (such as weeds) to the communities in which they occur, and to land-use systems.For economic botany to play an optimal role in the development of South Africa, a national survey of vegetation resources to supply detailed vegetation and plant distribution maps should be completed as soon as possible.
Priority assessment in economic botany is difficult, because many of the factors determining priorities lie outside the field of botany.Not only are economic botanists seldom told what priorities agriculture and industry have for plant research, but they are often asked to provide these priorities for others.For example, economic botanists are constantly being asked "What are the most important weeds in South Africa?"The answer to this question depends largely on non-botanical considerations: the losses that weeds actually cause, and our ability to control them.How ever difficult it may be, botanists will have to accept more responsibility in priority assessment, and will have to broaden their knowledge of agriculture and other fields that relate to botany.
If they are to function efficiently in decision-making in the future, botanists will have to: foster the team concept that can draw together the expertise that is needed from related disciplines; initiate and build up data banks to enable the vast amount of relevant material to be gathered, stored, sorted and retrieved; and promote the co-ordination of decision making.Only in this way will research in economic botany be directed to the real priorities-and fulfil its real functions.
The choice of priorities has a special importance to those in economic botany since, if their work does not pay off, they are "uneconomic" botanists.When they choose a project, the profit and loss account is not restricted to the economic botanist, since a chain reaction is set in motion.The control of a weed or the establishment of a new crop, for instance, will ulti mately involve a great deal of research input, labour and investment by agriculture and industry.For these reasons, the value of their work will be gauged not so much by its potential usefulness, but by the use that is actually made of it.This 'evaluation in terms of usefulness' is currently being applied to the work that has been done on nassella tussock.
The threat posed by nassella tussock has been spelt out in no uncertain terms (Healy, 1978;Wells, 1976).We believe this to be a disaster plant of unequalled importance to this country.If unchecked, it could result in most of the best pasture land being covered with tussock.I think that the manner in which we deal with nassella tussock will be a fair test of this country's intelligence, ability and will to preserve its pastures as well as its flora.At the same time, in the eyes of many researchers it will be a test of the useful ness and the validity of botanical research on pasture weeds.
My assessment of the changing scene in South Africa, and how it is likely to affect the future work of economic botanists, is as follows (Wells, 1971).The greatest world-wide needs for plant products are for more food, fjr more fuel, for new medicines, and for crops to replace sources of natural products that are either being exhausted (e.g.whale oil) or reaching their cultivation limits (e.g.timber for paper).Al though all these are of concern, the most immediate concern is likely to be with the r aional need for local sources of energy and raw materials and to provide new crops for local use.Everything suggests that man's future plant food needs will be met mainly by im proved breeding, selection and culture of established crop plants, rather than by some as yet undeveloped veld plant.Where established crop plants are con cerned, economic botanists have a role to play, since there is a great need for research on the biological characteristics of the world's principal food plants (Thimann et al., 1966).
Africa has produced few major food plants, but three of these, grain sorghum (derived from several wild Sorghum species), pearl millet (Pennisetum americanum) and water-melon (Citrullus lanatus), are important in Southern Africa.Sorghum is probably one of the most important crops for the future since it is the cereal best adapted to regions with warm, dry climates.This characteristic is shared by pearl millet, which is the main crop in the sandy soils of Kavango and Ovambo.These could be the crops that will be needed for marginal agronomic areas and for this reason thorough botanical and genetic studies of Sorghum, Pennisetum and Citrullus should be under taken.
Economic botanists also have a responsibility to collect material of primitive varieties of other crop plants grown by the local peoples.Preservation of these primitive cultivars is important for future crop breeding and development, and is urgent since they are likely to disappear as a result of the widespread monoculture of high-producing modern varieties.
Economic botanists must also contribute, through weed control studies, to primary food production.The extent of the contribution that can be made can be gauged from South Africa's average annual crop and pasture losses due to weeds which are estimated to be of the order of R600 million, equivalent to one-quarter of the total annual agricultural product.This estimate does not take into account the fact that agriculture does not stand alone, but is an integral part of the economic structure of the country, where industry handles agricultural products to the value of over R1 000 million every year (Anon, 1976).
The first task in weed research is to determine the occurrence, distribution and status of weeds.It is also obviously necessary to determine the weed groups, or complexes, that occur in association with particular crops and veld types, since without knowl edge of these complexes, research and control aimed at individual weeds is likely to be inefficient.
Well known also is the countrywide deterioration of the veld, accompanied by replacement of natural dominants such as Themeda triandra and Digitaria species by hardier, less palatable "caretaker" plants such as Eragrostis spp., Sporobolus spp., Elionurus argenteus and Chrysocoma tenuifolia.These caretaker species are the new dominants of much of the veld (Acocks, 1971).In the past they have been regarded as weeds.The universal application of good pasture management, effective control over the utilization of the veld, could halt veld deterioration and justify concentrating research on optimal use of the best climax grasses.But, if the veld is allowed to continue to deteriorate, we would do well to forget about climax grasses and concentrate instead on the use and conservation of caretaker species.
Weed status studies need to be followed by periodic monitoring to provide early-warning of aggressive weeds and by intensive studies on priority species and complexes.Studies of a few priority weed species, such as Opuntia aurantiaca, Stipa trichotoma (nassella tussock), Lantana, and Australian Hakea and Acacia species, have been undertaken in recent years by the State research institutes and by researchers at universities.(Zimmermann et al., 1974;Wells, 1976;Stirton, 1978;Neser, 1974;van den Berg, 1977).These studies are providing for the first time sound background information on aspects such as genetic variability, environmental requirements, pollination, propagation and dispersal mechanisms highly relevant to the control of the species concerned.There is an urgent need for economic botanists to provide further intensive studies of weeds and weed groups.It is not suggested that more than a small part of the estimated R600 million presently lost to weeds, can be saved by this research, but even 1 % represents R6 million, and it is certain that a great contribution to preventing further losses can be achieved by the early recognition and control of new weeds.
The need to produce more food will result in tremendous pressure on natural grazing lands, which cover 81 % of the area of South Africa (Edwards, 1978).The definition of arable land will broaden to include many areas presently regarded as marginal for cultivation.Pressures on the remaining area will have a great effect on indigenous plant communities.Clearing and thinning of woody vegetation to increase herb growth and animal production, are likely to take place over most of the 30 million hectares of bushveld, representing about one-third of the natural pastures of South Africa.Radical veld improvement, amount ing to veld replacement, is likely to take place as soon as suitable pasture legumes and grass mixtures are available.This replacement may be of the order of 1 0 % of available land in the drier areas, and up to 75% of available land in the wetter areas, such as the foot-hills of the Drakensberg.
It is undoubtedly the duty of botanists to contribute to these changes coming about in an orderly and con trolled manner.Contributions are already being made to two projects.Production studies in the bush veld or 'savanna eco-system' contribute to a knowledge of how best to manage this community whilst ob taining optimal grazing and browsing (Rutherford, 1978).A cytogenetic study of the Eragrostis curvula complex, which has resulted in eight fully sexual plants being found and brought into cultivation, has for the first time made controlled breeding for selected characteristics of this grass a possibility (Vorster & Liebenberg, 1977).Such research on indigenous gras ses and legumes needs to be expanded.New weed problems are certain to arise in the wake of plough ing marginal arable areas, and in areas where radical veld improvement is attempted.Veld replacement, a costly operation whose success depends on its per manence, is particularly vulnerable to weed problems.Woody invaders and tussock grasses such as nassella tussock, could find the conditions provided by attempts at veld improvement and replacement highly suitable for them.It is essential that the threat posed by these weeds, which are capable of causing agri cultural disasters, should be removed so that agri cultural options can remain open.Economic botanists will undoubtedly have important work to do on these weeds, and on indigenous veld species that become weeds in new situations.
Experience in other countries points to the fact that more and more indigenous plants will come to be regarded as weeds, as man tries to utilize more and more of the habitat which he shares with them (Reed, 1970).It will be the task of economic botanists to take the initiative in assessing the status of both indigenous and exotic weeds, and to help determine where and how research and control should take place.In the meantime, it is not necessary to carry out weed status surveys in order to know that certain weed problems demand attention.The invasion of the South African flora by Acacia spp., Eucalyptus spp., and Hakea species from Australia is proceeding unabated.Soon, unless very positive action is taken, these sometimes very useful Australian plants will have completely replaced the few remnants of low land fynbos communities.As a matter of urgency, a report, similar to the nassella tussock report, must be produced, setting out the alternatives in unequivocal terms, the steps that must be taken in the light of existing knowledge, and the priority areas for re search and control.
The search for new crops and replacement crops begins with South Africa's indigenous flora of 17 000 species.Here the first responsibility is to preserve the available plant resources.Second is the need to preserve man's knowledge of this vegetation.With the advance of civilization, knowledge of folk uses of indigenous plants is rapidly disappearing.Economic botanists have a responsibility to collect and store the folk knowledge of indigenous peoples, and to use it in the search for new crops and products.
The hunt for new crops and replacement crops is closely linked to primary food production.South Africa has limited arable land, where the biggest challenge is to find new crops that do not compete for this space.Sugar is a valuable export crop, but it occupies vast areas that could be used for other food production.Sisal started life as a dry-area crop, but now competes with sugar and other food crops for a place in the wetter, higher production areas.More land is needed for afforestation in South Africa.At first only poor agricultural land was used for afforestation, but expansion is bringing forestry into competition with agriculture and with the need for catchment protection for water supplies.Sweeteners to replace cane sugar, and annual dryland paper crops to replace timber pulp, provide promising areas of research for economic botanists to help relieve crop competition pressures.
Plant utilization research can also make a direct contribution to conservation.Invasive Australian Acacia species, that threaten the flora, are still being planted as sandbinders, for lack of suitable indigenous replacements.This is seriously limiting the effective ness of weed control, and there is an urgent need to explore the potentials of indigenous ground covers, sand-binders and barrier plants (Boucher & Boucher, 1978).
At present industrial needs for replacement crops, for local sources of gums and other products, are handled on an ad hoc basis, and the small group of economic botanists available in the country is illequipped to cope with sudden demands for research of this kind.A systematic survey of strategic plant products should be carried out by industry, so that research priorities can be decided on, and so that economic botanists can plan how best to provide for the needs of industry.
It is likely that in the future industry will tend to employ its own economic botanists, but whether this will be on a sufficiently long term basis to provide job security in the profession remains to be seen.The solution to industries' needs may well lie with private firms carrying out work on a contract basis, with the state and the universities providing consultative services.This arrangement would also have the advantage of freeing state researchers to concentrate on studies, such as weed investigations and native uses of plants, that are beyond the scope and interest of private firms.
The development of economic botany in both the public and private sectors is not proceeding as rapidly as the needs of the country demand.There is a chronic shortage of economic botanists in South Africa.At present, although South Africa has one of the richest floras in the world and an almost untapped economic source, there are only a handful of research ers to work on its utilization.One of the most im portant tasks facing the small economic botany community in South Africa will be to provide universi ty training to stimulate the supply of researchers to ranks of the profession.The role that economic botany can play will depend largely on the success of this venture.
Results, and the use of results, are extremely important to economic botany.This fits into the broader pattern in agriculture, where the utilization of results has never been more important and where it has in some cases become so crucial that research must take second place to extension.In botany there is undoubtedly a gap between research and extension and it will have to be bridged by research personnel fully able to interpret the results of their discipline and to ensure that research results do not lose validity in presentation and application.Even though there are many gaps in our knowledge of the 17 000 indigenous plant species occurring in South Africa, botanists possess a great deal of knowledge about them that has not been used.Most of these species have been described and named.Their distribution and the conditions that seem to suit them are mostly known.It is possible, without leaving the herbarium, to produce a preliminary assessment of many potentials of these plants, for example, their potentials as shade trees, hedges, ground covers and decorative subjects for different areas can be assessed.There is nothing to stop these things from being done except manpower, and a decision of priority.

Opsomming: Landbousektor
The challenge before economic botanists is to make the best of the natural resources that are avail able.Relatively speaking, South Africans have been spoilt by the bounties of the veld.But in the future it will be the countries that can feed themselves and clothe themselves that will be strong and independent.Neither scientist nor layman can afford to neglect the plant-enemies or the productive plants that can contribute to our well-being.

The biological control o f jointed cactus in South Africa.
In Report of First National Weeds Conference (unpublish ed).204-211.
Davy in the Transvaal Department of Agriculture.In those days agriculturists were not trained in agricultural disciplines.Instead, they were trained as botanists or chemists and became crop scientists by adoption.As such the botanist was very much involved in the seedling stages of agricultural development in South Africa.
In later years, disciplines such as agronomy, horticulture, pasture science and plant pathology emerged.However, botany remained fundamental to the understanding of the plant itself, its vital processes, habits and habitats, as well as its relationships.
Therefore, crop and pasture science, in striving for the solution of agricultural problems, still has to rely on principles developed by carrying on research deeply into basic botany.
Mr Chairman, the future role of botany for en hancement of improved food supply and stable agriculture will be even more important than in the past.In addition to the conventional means of im proving crop production, we urgently need to advance our knowledge of photosynthesis, genetic manipula tion, biological nitrogen fixation, uptake and utiliza tion of moisture and nutrients as well as the biological stress (insects, diseases, nematodes and weeds), to establish principles to increase crop yields.
Green plants, as yet, are the primary harvesters of free solar energy.We need this energy as food, but as we are using up our fast-disappearing oil, natural gas and other fossil fuels we may have to turn from mining fuel to growing it.Yet, do we have sufficient knowledge of the bio-chemical events leading to carbon fixation and the processes of dark and photo respiration for improving photosynthetic productivi ty?
Mr Chairman, of all the numerous measures which contribute towards greater crop production the one at present showing best results is judicious fertilizer use.Yet, only 50 per cent of the nitrogen and less than a third of the phosphorus and potassium applied as fertilizer is recovered by crops.The balance is lost to the environment and meanwhile fertilizer prices are escalating.
With the energy use and capital costs of fertilizers we need to develop crops which are nearly nitrogen self-sufficient through symbiotic nitrogen fixation and seek micro-organisms for supplying nitrogen to cereals and grasses.
Meneer die Voorsitter, in die verlede het die resultate van plantkundige navorsing die landboubedryf onderskraag.In die toekoms sal selfs meer kundigheid van hulle verlang word om hulle bydrae te kan lewer.Daarom wens ons hierdie Instituut alle sukses toe vir die volgende 75 jaar en daarna.By this time it should be clear that the influence of the Botanical Research Institute (BRI) extends far beyond purely, or solely, agricultural application.To complete my summary I shall confine myself to examples of involvement and co-operation between this institution and the one which I happen to repre sent, namely the CSIR, since such examples may no doubt be extrapolated to testify of the experiences and sentiments of many other institutions also.

Opsomming: Nie landbousektor
In the field of chemistry, when analysing products, the collection and correct identification of plants is extremely important.Thus in a project aimed at determining alkaloid concentrations in no less than 3 000 plant species on behalf of an American phar maceutical sponsor, the National Chemical Labora tory relied heavily on the closest of collaboration with the BRI.Likewise the investigations by the National Food Research Institute on the nutritive value of edible veld fruits have led to an exchange of expertise which is held in high regard by both parties concerned.
The National Institute for Water Research records numerous examples of co-operation ranging from the photographing of pollen grains by means of a scan ning electron microscope and the making available to the BRI of limnological sampling apparatus, to their extensive use of the library facilities on the Brummeria * Gaan dit nie 'n herdruk beleef nie?Die eksemplare tans nog in omloop het vandag groter versamelaars-as gebruikswaarde vanwee hul skaarsheid !site.Clearly the most direct and uninterrupted collaboration with BRI, which also points to areas of undoubtedly common interest, stems from its partici pation in various Co-operative Scientific Programmes which are being co-ordinated by the CSIR.This includes seemingly trivial gestures such as the cata loguing and safe-storage of botanical material emanating from SASCAR's Marion Island involve ment, as well as ostensibly highly sophisticated monitoring by means of remote sensing of the extent and occurrence of fire in the different veld types of South Africa, with particular reference to its ecological impact on veld management.
Within the last 150 years, population numbers and their distribution, land use and socio-economic conditions, have undergone major changes in South * Assistant Director, Botanical Research Institute, Depart ment of Agricultural Technical Services, Private Bag X I01, Pretoria, 0001.
A f r i c a ., 1919.Kew Bull.399-403.E d w a r d s , D ., 1974.Survey to determine the adequacy of conserved areas in relation to vegetation types.A preli minary report.Koedoe 17: dat ons by hierdie geleentheid twee vorige direkteure, dr R. A. Dyer en dr L. E. Codd en die huidige direkteur, dr B. de Winter, persoonlik kan bedank vir hulle bydrae tot Plantkunde in Suid-Afrika.Ons dank ook aan almal wat voor en saam met hulle was en is, vir hulle bydraes.Mr Chairman, the germ that developed into the Botanical Research Institute originated in Pretoria in 1903 with the appointment of Dr Joseph Burtt * Hoofdirekteur, Akkerbou en Weiding, Departement van Landbou-tegniese Dienste, Privaatsak 116, Pretoria, 0001.
THE ROLE OF BOTANY IN THE DEVELOPMENT OF THE REPUBLIC OF SOUTH AFRICA WITH SPECIAL EMPHASIS ON THE CONTRIBUTIONS OF THE BOTANICAL RESEARCH INSTITUTE Toxicology Section of Onderstepoort, and at present the Institute has an authoritative book on poisonous plants in the press, which should prove a useful reference work.We have played our part in weed identification, and Botanical Survey Memoir 37 is devoted to "Common weeds in South Africa".Also, we are presently involved in the study of important weeds such as Stipa trichotoma (Nassella tussock), Hakea species, Opuntia aurantiaca (Jointed cactus),