International Code of Nomenclature for Cultivated Plants (ICNCP)

The International Code of Nomenclature for Cultivated Plants (ICNCP) regulates the naming of cultivars, cultivar Groups and graft-chimaeras. Examples are
» Clematis alpina 'Ruby' : a cultivar within a species
» Magnolia 'Elizabeth' : a hybrid between at least two species
» Rhododendron boothii Mishmiense Group: a Group name
» Crataegomespilus : a graft-chimaera of Crataegus and Mespilus.

Note that the ICNCP does not regulate trademarks for plants: trademarks are regulated by the law of the land involved. Nor does the ICNCP regulate the naming of plant varieties.

Orchids have a Code of their own that operates within the limits set by the ICNCP.

Many of the Rules in the International Code of Nomenclature for Cultivated Plants (Cultivated Plant Code or ICNCP) deal with sorting out problems which have arisen in past nomenclature. The following short notes are intended as a quick guide to forming new cultivar names and should be read by anyone wishing to name a new cultivar. For precise regulations, the ICNCP is to be consulted.

The need for a comprehensive set of practical, easily understood and internationally acceptable regulations on the naming of cultivated plants has long been evident. The first step in the formulation of the International Code set out below was made in 1862 by Alphonse de Candolle in a letter subsequently placed before the International Horticultural Congress of Brussels, 1864. De Candolle wished to reserve Latin names for species and varieties and to use only non-Latin 'fancy' names such as 'Bijou', 'Rainbow', etc., for garden forms. He suggested that this common, traditional and ancient practice should be made the only practice. The celebrated Capitulare de Villis (A.D. 812) of the Emperor Charlemagne provides an early illustration of such procedure, apples in general being mentioned therein under the Latin name malus; but the kinds distinguished by vernacular names: "malorum nomina; gozmaringa, geroldinga, crevedella". The present-day extensive use of arbitrary names, often those of persons in no way connected with the raising of the plant, seems to have begun in France and the Netherlands in the early seventeenth century. An unprecedented number of diverse new tulips. raised from seed then called for names. It became customary to, name in the same manner new plants of garden origin belonging to other genera.

As a cultivar of a new sub-species (specifically propose or accidental hibridization) some of the questions which has to be kept in mind to follow the norms of ICNCP are:

Do you have a new cultivar?
You have a new cultivar and you wish to name it. First check that you do actually have a cultivar. A single plant is not a cultivar: a cultivar is a group of individual plants which collectively is distinct from any other, which is uniform in its overall appearance and which remains stable in its attributes. Do not attempt to name a cultivar until you have a number of individuals that are uniform and stable. Now convince yourself that your cultivar is really worth naming; there is no point in going through the process of naming your cultivar if it is not an improvement on others.

There are different sorts of cultivar ranging from clones, which should be genetically identical, to tightly controlled seed-raised cultivars such as F1 hybrids. Article 2 of the Code describes some of the different kinds of cultivar.

The only way you can check if your cultivar is new and distinct is by comparing it with existing cultivars. Your new cultivar must be distinguishable from others that exist or have existed.

Once you are satisfied that you do indeed have a new cultivar, decide if you want to give it a cultivar name. A name is made up of a botanical name in Latin (or its common-name equivalent) for a genus or species followed by a cultivar epithet which is the last part of the entire name and which renders the name unique. Cultivar epithets are always written within single quotation marks (never double quotation marks) so that they stand out from the rest of the name and so that their status is obvious.

Remember that cultivar names, by their very definition, are available for all to use and that the names themselves offer no protection if you wish to obtain intellectual property rights on your new cultivar.

How do I form a new cultivar name?
The full name of a cultivar will always begin with the name of the genus to which the cultivar belongs. Optionally, the species or hybrid epithet may be included as a second element in the entire name but this is not usually necessary; inclusion of such epithets merely provides more information about your cultivar.

Since 1959, new cultivar epithets must be in a language other than Latin and they must be unique within the so-called denomination class which is usually the genus. A few groups have special denomination classes and these may be found listed in Appendix III of the Code.

Coining a new and original cultivar name is not easy, especially in groups which historically have had hundreds or even thousands of cultivars. Luckily many of these groups have International Cultivar Registration Authorities (ICRAs) who publish checklists and registers of names which are in use or which have been used in the past. You can search in the alphabetic list of genera in these pages to see if the genus of your cultivar is covered by an ICRA and then consult the ICRA's publications or contact the particular ICRA Registrar directly. Registrars will be glad to advise you if your proposed name has been used before and whether or not your name is in an acceptable form.

There have been many other lists of cultivar epithets produced in the past and a fairly comprehensive list of those is given in Appendix XI of the 1995 edition of the Code. This list of Checklists is kept up to date at Delaware State University (USA). Good horticultural and botanical libraries are likely to have copies of many checklists, registers, and other publications for you to check through prior to publishing your proposed name.

Thinking up a cultivar epithet requires a bit of care. An ideal epithet is both easy to spell and pronounce in the various countries through which the cultivar might be distributed. The rules for forming an epithet allow you to use or make up any word or words you want but the epithet will not be allowed as a cultivar epithet if it is confusing or likely to confuse or if it is contrary to the few provisions listed below. The Code governs the reasons why a proposed epithet might not be allowed: epithets not formed in accordance with the Code are to be "rejected".

  1. The following are some of the Rules to follow when formulating a new name:
    1. Make sure your proposed name is unique and that the epithet is in a modern language other than Latin. (ICNCP Art. 19.13-19.14)
    2. Make sure that your name cannot be confused either in spelling or pronunciation with an existing one. (ICNCP Art. 19.15)
    3. Make sure that your name could not be interpreted as being likely to exaggerate the merits of the cultivar. (Art. 19.26)
    4. Make sure that the epithet of your name has no more than 10 syllables and no more than 30 characters, excluding spaces and the single quotation marks. (ICNCP Art. 19.15)
    5. Make sure your epithet does not consist of a single letter or solely of numerals (ICNCP Art. 19.16)
    6. Do not use any of the following banned words (or their equivalents in any language) in your epithet: "cultivar", "grex", "group", "hybrid", "maintenance", "mixture", "selection", "series", "sport", "strain", "variety" (or the plural form of these words in any language) or the words "improved" or "transformed". (ICNCP Art. 19.19-19.20)
    7. Do not use any punctuation marks except for the apostrophe, the comma, a single exclamation mark, the hyphen and the full-stop (period). Do not use fractions or symbols unless they are specifically permitted. (ICNCP Art. 19.21-19.22)
    8. Make sure that your epithet is not, or does not contain, the Latin or common name of its genus or the common name of any species in that genus if use of such might lead to confusion. (ICNCP Art. 19.23-19.24)
    9. Make sure that publication of the cultivar�s name is not against the wishes of its raiser or breeder. (ICNCP Art. 28.4)

  1. Other Recommendations to bear in mind: In addition to the Code's Rules for forming a new cultivar name, contravention of which will cause it to be rejected (ICNCP Art. 28.1), the following Recommendations, designed to avoid confusing or misleading buyers of plants, should be followed.
    1. (a) Epithets should be as short as possible and not difficult to write or pronunce. (ICNCP Rec. 19A.1)
    2. Avoid epithets that might resemble terms used in the market-place. (ICNCP Rec. 19C.1)
    3. Avoid epithets only made up of simple descriptive words that are likely to become common adjectives within a group of cultivars within the denomination class. (ICNCP Rec. 19D.1)
    4. Avoid epithets that might give a false impression as to the attributes of the cultivar. (ICNCP Rec. 19E.1)
    5. Avoid epithets that imply that the cultivar is derived from another when this is not the case. (ICNCP Rec. 19F.1)
    6. Avoid epithets that give the false impression as to its raiser, breeder or origins. (ICNCP Rec. 19G.1)

  1. Further provisions: You should also bear in mind that if a new cultivar is likely to be registered with a statutory plant registration authority for purposes of e.g., national listing or plant breeders' rights, other conditions are likely to be required before a name (denomination) is approved by the appropriate authority. Each authority has its own rules, but the following additional conditions are often encountered:
    1. If your epithet contains the name of a living person, make sure you have asked their permission to use their name. (ICNCP Rec. 19B.1)
    2. Do not incorporate either abbreviations for the names of international organizations that are excluded from trade mark protection by international convention or trademarks themselves in a cultivar name. (cf. ICNCP Art. 28.3)
    3. Do not use names which might cause offence in the country where a cultivar is to be marketed. (ICNCP Rec. 19.H.1)

What do I do with my new name?
Assuming that your name is not due to be submitted as part of an application for statutory registration, then once you have satisfied yourself that your name is in an acceptable form, register it with the appropriate ICRA. This will cost you little more than time spent filling in a form and sending it off but will help ensure that the name is internationally recognized forever.

The name will have to be published in order to be fixed. You may either publish it yourself, say in your nursery catalogue if you are a nurseryman, or the ICRA concerned will publish it for you in due course if you register the name with them. ICRAs however are placed under no obligation to publish your name within a short period of time and you should realise that your chosen name might be used by someone else for a completely different plant unless you take steps to ensure early publication. If someone else, even if in a different part of the world, publishes your chosen name for a different cultivar in the same genus or other denomination class, you will have to think of another.

Publication of your new name must be in printed or similarly duplicated matter which is distributed to the general public or at least to botanical, agricultural, forestry or horticultural institutions with libraries. Newspapers, gardening or non-scientific magazines and similar publications which are not designed to last do not count as publications in this case. Publication on the World Wide Web or on CD-ROM does not count as publication since the pages are not permanent.

Publications must be dated. A new name appearing in a nursery catalogue will not be treated as having been published if that catalogue is not dated at least to the year.

Do not publish more than one name for the same cultivar in the same publication: if you do this none will be considered as having been published in that publication.

It may be that you are registering or publishing a new cultivar name on behalf of someone else or that you are promoting a new name for a cultivar raised by someone else. Check that the originator of the cultivar agrees with the proposed name (and its spelling) that you are promoting; if the originator does not, the name may have to be rejected later in favour of the originator's choice.

When you publish a new cultivar name, you must include a description of the cultivar. The longer and more complete the description the better, but at least state its obvious characteristics and if you can, state how it differs from an existing cultivar. It is helpful, but not compulsory, to provide an informative illustration of the new cultivar in the publication if expense permits.

Make a statement such as "new cultivar name" (not just "new" or "new cultivar") after the proposed name so that others may recognize the fact that you have deliberately published a new name for the first time. If you regularly publish new cultivar names, it would be most advantageous to list any new names appearing in your publication in a single place in that publication.

How can I protect my new name?
Send a copy of your publication to the ICRA and to the main horticultural libraries in your part of the world. If you are feeling generous, send copies to similar libraries in other parts of the world too.

If you can, distribute material for making nomenclatural standards and other herbarium specimens of the new cultivar to as many herbaria as is practical, especially to the nearest herbarium that specializes in maintaining nomenclatural standards (a list is provided in Appendix IV of the Code), This will help ensure that your cultivar will not become confused with others in the future and may help resolve disputes if more than one person thinks they have raised the same cultivar!

Finally, ensure that the name is used by everyone and do not encourage others to coin trade-designations or other selling names for your plant. The most effective way to protect a name is to label your plants clearly and unambiguously. Always maintain "your" cultivar epithet within single quotation marks to ensure that the status of your plant is understood.

History of ICNCP

The 1864 Brussels Congress was followed by the 1865 International Botanical and Horticultural Congress of Amsterdam. Here Karl Koch likewise drew attention to the confusion produced by the use of Latin names for garden forms. In 1866, at the International Botanical Congress of London, Koch suggested that such international congresses should deal with matters of nomenclature. Alphonse de Candolle accordingly drew up his celebrated Lois de la Nomenclature botanique; which were discussed and officially accepted by the International Botanical Congress of Paris, 1867. They form the basis of the present International Code of Botanical Nomenclature (1952). De Candolle's Article 40 dealt with the names of plants of horticultural origin and gave formal expression to his proposal of 1862: "Seedlings, half�breeds (metis) of unknown origin and sports should receive from horticulturists fancy names (noms de fantaisie) in common language, as distinct as possible from the Latin names of species or varieties. When they can be traced back to a botanical species, subspecies or variety, this is indicated by a succession of names (Pelargonium zonale, Mrs. Pollock)." Article 40, its wording almost unchanged, survived the redrafting of the International Rules of Botanical Nomenclature down to 1935. It is now embodied in the International Code of Botanical Nomenclature (1952), Article 38, and in the following Code (Article C. 15), as a basic regulation.

This Article was the only one in the International Rules of Botanical Nomenclature adopted at the Botanical Congress of Vienna, 1905, which referred directly to the naming of garden plants. Its inadequacy soon became apparent. Alfred Cogniaux accordingly attempted to supplement the 1905 Article 30 by formulating a set of "regles de nomenclature horticole." To ascertain informed opinion he sent twenty questions on matters of horticultural nomenclature to some forty persons in Belgium, France, Germany, Java, Russia, Switzerland and the United Kingdom whom he judged to be particularly interested and competent. It is no coincidence that the forty included many people interested in the naming of hybrid orchids, for by their quick increase in number these plants now presented the horticultural world with problems of nomenclature somewhat comparable to those which tulips had evoked nearly three centuries earlier.

Among the memoranda submitted was a long and important one from The Royal Horticultural Society of London, which had formed from its Orchid Committee and its Scientific Committee a subcommittee on horticultural nomenclature, and this subcommittee was represented at the subsequent Congress by E. A. Bowles and A. B. Rendle. Cogniaux correlated the replies and submitted a report to Section IV Subsection B of the International Congress of Brussels, 1910. The subsection devoted two long meetings to their consideration. Out of the results of this discussion Cogniaux formulated the "Regles de nomenclature horticole" adopted by the Brussels Congress. He intended to submit them to the next International Botanical Congress which should have been held in London in 1915. By then the world was at war and the Congress did not take place. In 1917 Cogniaux died, aged 75 years. His code of horticultural nomenclature was thus never ratified, although most of its provisions have since become general procedure.

Meanwhile in the United States parallel efforts to evolve codes of nomenclature for cultivated plants were being made by specialist bodies, notably by the American Pomological Society [The American Pomological Society's original code dates from 1867, but was based on the even earlier 'Rules for American Pomology' agreed in 1847 by the Cincinnati, Massachusetts and Pennsylvania Horticultural Societies and published in Downing's The Horticulturist and Journal of Rural Art 2: 273-275 (1847), 480-431 (1848); cf. Hume, Camellias in America 222 (1946). These 1847 pomological rules, formulated twenty years before the first laws of botanical nomenclature, represent "the first movement made on either side of the Atlantic towards fixed laws of nomenclature", as Downing noted at the time. They anticipated the botanical code by accepting priority of publication as decisive and they chose, moreover, two standard works, one European, the other American, as starting points for the nomenclature of fruits, thus anticipating the 1930 suggestion on which Art. C. 12 of this International Code is based. The essential parts of Art. C. 6-9 and 21 are derived from these 1847 American pomological rules.] and the American Society of Agronomy. For the latter C. R. Ball and J. Allen Clark drew up a code of nomenclature adopted by the Society in November 1917 and published in the Journal of the American Society of Agronomy 9: 425-427 (December 1917), 10: 91-92 (February 1918). The influence of these codes in the United States has been considerable. They have, however, been as little known outside the United States as Cogniaux's "regles de nomenclature horticole" and the "Nomenklaturregeln fur den deutschen Obstbau" (cf. Neue Berliner Gartner�Borse 3 nr. 9; 3rd May 1949) have been known in the United States. Generally applicable provisions taken from all these and various other codes produced by specialist bodies were carefully studied and discussed during the preparation of the International Code of Nomenclature for Cultivated Plants given below. This present Code thus has a firm basis in both European and American experience over the last forty years.

The International Botanical Congress planned for 1915 did not take place until 1930. In 1927, however, at the 8th International Horticultural Congress, an International Committee for Horticultural Nomenclature was set up with A. B. Rendle, Keeper of Botany, British Museum (Natural History), as chairman, and F. J. Chittenden, Director of The Royal Horticultural Society's Gardens, Wisley, as secretary. Both had helped to prepare The Royal Horticultural Society's 1910 Brussels memorandum. The connexion between the Natural History Museum, The Royal Horticultural Society and horticultural nomenclature has thus been long and intimate. The immediate task of this Committee was the one which Cogniaux had tackled in 1910, i.e. to supplement the International Rules of Botanical Nomenclature with rules 'for the naming of garden plants. No direct attention, however, seems to have been paid to Cogniaux's excellent pioneer work. At the 9th International Horticultural Congress of London, held in July 1930, the Nomenclature Committee was enlarged. It drew up a new set of rules which were presented as resolutions to the International Horticultural Congress and duly passed. A month later at the 5th International Botanical Congress, held in Cambridge in August 1930, Rendle called attention to the work of the London Horticultural Congress Committee. He stated that its rules contained nothing contrary to the International Rules of Botanical Nomenclature, and he then proposed that they should be added to the third edition as an appendix. The Subsection of Nomenclature accepted this proposition and as Appendix VII (Nomenclature of Garden Plants, by A. B. Rendle) they appeared in the third (1935) edition of the Rules. By this action the nomenclature of cultivated plants became once more the joint concern of both horticulturists and botanists.

An important suggestion made at the 1930 International Horticultural Congress was "that the starting point for nomenclature of horticultural groups should be:
  1. some recognized horticultural monograph; or
  2. An ad hoc list of varieties drawn up by a recognized body of specialists in the particular group; or
  3. where such bodies do not exist, by some recognized society which shall be specially charged with the work.
Such lists should be kept up to date by (b) and (c), and additions periodically published through some recognized medium" (IX Int. Hort. Congr. Rep. 29).
The merits of this suggestion led to acceptance at the 11th International Horticultural Congress, Rome, 1935, of the proposal that priority for names of horticultural varieties should rank from the date of acceptance of a list of each group by an International Horticultural Congress. A list of such works relating to carnations, dahlias, gladioli, irises, narcissi, orchids, rhododendrons, lilacs (Syringa), tulips and ferns was also accepted at the 11th International Horticultural Congress, of which, however, the proceedings remain unpublished. At the 12th International Horticultural Congress held in Berlin in August 1938, lists relating to conifers, delphiniums, day-lilies (Hemerocallis) and peonies were also approved. It was then decided that these should be adopted as standards of nomenclature for six years, i.e. until August 1944, by which time but for the Second World War another Congress would have been held. The lists themselves have thus long ceased to have validity under this proposal, but the concept of different starting points for the nomenclature of different cultivated groups is a sound one, paralleled in the International Code of Botanical Nomenclature (Article 23) by the different starting points for the nomenclature of mosses, lichens, fungi, algae, and fossil plants. It has accordingly been incorporated, in the following Code (Article C. 12), the year 1753 being taken as a general starting point.

Apart from this the 1930 rules underwent little addition or modification at the International Congresses of Paris (1932), Rome (1935) and Berlin (1938). Rendle died in January 1938. His place as chairman was taken by F. J. Chittenden, while R. Zander became secretary of the Permanent Horticultural Nomenclature Committee, as it was then named. It was reconstituted anew in 1950, with W. T. Stearn (U.K.) as secretary, and since November 1951 has been known officially as the International Committee on Horticultural Nomenclature and Registration and informally as the London Committee. Its re-organization was made necessary by the death of Chittenden in 1950.

Meanwhile, dissatisfaction with the inadequacy of the rules for the nomenclature of hybrids and other genetically complicated groups increased. The American Society of Plant Taxonomists accordingly submitted a group of proposals to the 1948 symposium on nomenclature at Utrecht. The Utrecht gathering requested W. H. Camp, in collaboration with other interested persons, to present formal proposals on these matters to the 7th International Botanical Congress. The American Horticultural Council then brought forward suggestions, from a committee comprising C. G. Bowers, G. H. M. Lawrence, P. A. Munz and J. F. Styer, which dealt with the rules for the naming of cultivated plants. After circulating the combined proposals, Camp edited and published them in the American Journal of Botany 37: 31-38 (January 1950) and submitted them to the 7th International Botanical Congress at Stockholm, 1950. Here the Subsection on Nomenclature set up a special committee (now known officially as the Committee for the Nomenclature of Cultivated Plants and informally as the Stockholm Committee) to consider such proposals.

Camp (U.S.A.) acted as chairman of this Committee and W. T. Stearn (U.K.) as secretary; the other members were H. H. Allan (New Zealand), B. K. Boom (Netherlands), J. M. Cowan (U.K.), H. P. Daepp (Switzerland), J. E. Dandy (U.K.), J. S. L. Gilmour (U.K.), N. Hylander (Sweden), G. H. M. Lawrence (U.S.A.), H. W. Rickett (U.S.A.), R. C. Rollins (U.S.A.) and F. C. Stern (U.K.). The Committee met regularly for two weeks. Its recommendations were adopted by the Botanical Congress, those relating to hybrids in general being officially passed for addition to the International Code of Botanical Nomenclature (1952), of which they now form Appendix H; those relating to the old Appendix VII (the 1930 rules) were accepted in principle, their final adoption being made conditional on their discussion and approval by a parallel committee of horticulturists acting under the auspices of the International Committee for Horticultural Congresses. Early in 1951 the new draft of the rules resulting from the work at Stockholm was circulated widely. As a result of this publicity, by September 1951 many proposals for its emendation had been received and correlated; to them the secretary added proposals suggested by the study of the Nomenklaturregeln fur den deutschen Obstbau, the Code of the American Pomological Society, etc.

To prepare the ground for the nomenclature meetings of 1952 a joint meeting of the London Committee and the Stockholm Committee took place at The Royal Horticultural Society's Offices, London, on November 22-24, 1951, in the same manner that the symposium on nomenclature at Utrecht in 1948 preceded the Botanical Congress at Stockholm in 1950. Without such a preliminary meeting neither Congress could have satisfactorily got through the vast body of nomenclatural business before it in the time available. The joint London meeting was attended by A. P. Balfour (U.K.), Boom (Netherlands), Camp (U.S.A.) chairman, Cowan (U.K.), J. W. S. Cracknell U.K.), Daepp (Switzerland), Dandy (U.K.), Gilmour (U.K.), H. G. Hillier (U.K.), Hylander (Sweden), W. E. Th. Ingwersen (U.K.), J. Lange (Denmark), J. Lanjouw (Netherlands), R. Maatsch (Germany), J. M. S. Potter (U.K.), Stearn (U.K.) secretary and convenor, Stern (U.K.), A. Thorsrud (Norway), R. de Vilmorin (France) and R. Zander (Germany) as official voting members and A. G. L. Hellyer, A. Simmonds and P. M. Synge as observers participating in the discussions. Under the stimulating chairmanship of W. H. Camp the joint Committee discussed item by item the Stockholm new draft and the additional proposals. Despite the considerable initial divergence of views natural to so big an international assembly of experts representing a diversity of horticultural and botanical interests, the joint Committee reached general agreement on all points. The task of formally drafting, correlating and arranging these decisions into a code was then entrusted to an editorial subcommittee consisting of Camp, Gilmour and Stearn. The agreed text appeared in the Journal of The Royal Horticultural Society 77: 160-172 (May 1952). The 42,000 copies distributed brought proposals for its emendation from Australia, East and West Germany, Czechoslovakia, Malaya, the United Kingdom and the United States, a proof of the wide publicity which the code had received and the interest it had aroused. Of these proposals the most extensive came from Germany, where the Deutsche Gartenbau-Nomenklatur�Ausschuss redrafted almost the whole code. They were correlated by the secretary and circulated to members of both Committees just before the opening of the 13th International Horticultural Congress of London in September 1952.

The International Committee on Horticultural Nomenclature and Registration met every day from the 7th to the 13th of September 1952 in joint session with members of the Stockholm Committee for the Nomenclature of Cultivated Plants. These meetings were open to the general public. They were attended by Balfour (U.K.), Boom (Netherlands), C. G. Bowers (U.S.A.), Cowan (U.K.), Cracknell (U.K.), Daepp (Switzerland), Dandy (U.K.), H. Duperrex (Switzerland), S. B. Emsweller (U.S.A.), Gilmour (U.K.), H. J. Grootendorst (Netherlands), A. Guillaumin (France), Hylander (Sweden), Ingwersen (U.K.), H. A. Jones (U.S.A.), Lange (Denmark), A. Lecrenier (Belgium), Maatsch (Germany), J. R. Magness (U.S.A.), Potter (U.K.), H. A. Senn (Canada), Stearn (U.K.), Stern (U.K.), Thorsrud (Norway), Vilmorin (France) and Zander (Germany) as Committee members. Although voting was restricted to the above official members of the two Committees, all persons present were invited to participate freely in the discussions. Non-members who thus took part included T. H. Everett (New York Botanical Garden), L. D. Hills, R. E. Holttum (University of Malaya), A. Nehrling (Massachusetts Horticultural Society and American Rose Society), C. North (National Institute of Agricultural Botany, Cambridge), B. Park (National Rose Society), T. R. Peace (Forestry Commission), D. Sander (British Orchid Growers Association), G. M. Schulze (Botanischer Garten, Berlin-Dahlem), Simmonds (R.H.S.) and Synge (R.H.S.). Their cooperation ensured that a wide range of views and interests was taken into consideration and it proved of great value. The meetings took place under the chairmanship of Thorsrud, with Gilmour as deputy chairman, Stearn as secretary and rapporteur general, and J. Souster (Royal Botanic Gardens, Kew) as recorder. The subcommittee on registration consisted of Cracknell, Grootendorst, Maatsch, Nehrling, Park, Sander and Simmonds.

Camp (U.S.A.), who had played so important a part in the 1950 Stockholm and 1951 London discussions, was unfortunately not able to attend the Congress. Letters to the secretary from American organizations and individuals and the presence of American representatives ensured that American views and interests were adequately championed. Fortunately, no one approached any matter in a nationalistic and aggressive spirit. A friendly, constructively critical, frank and cooperative attitude characterized the representatives of all nations taking part. Without such an attitude and without free discussion it would have been impossible for the joint Committee to have covered its extensive agenda in the time available arid to the satisfaction of all concerned.

The Committee considered in detail the 'Proposed International Code of Nomenclature for Cultivated Plants' and the amendments and additions put forward. It kept in mind the need for the minimum disturbance of existing names and sought to provide sound guidance for future procedure. It reached general agreement on every matter discussed, and thus was able at the end to recommend to the Congress as a whole a revised text essentially similar to the 'Proposed International Code' but with many small amendments and additions. Since it was not practicable to lay before the Congress at its final session the complete text, the Congress was asked to give its approval to the main points embodied in the Code (Articles C. 1, 2, 4-8, 10, 13, 15-17, 23, 25, 29, 34) [The letter 'C' (for cultivated plants) has been placed before the number of each article of this Code to obviate confusion with the articles of the International Code of Botanical Nomenclature (which have no preceding letter) and its Appendix II, 'Names of Hybrids' (which are preceded by the letter 'H'] and set out in a report distributed to all persons attending this session. Gilmour gave an address explaining their intent and implications. The Congress then formally adopted a resolution expressing its approval of these main points and charging the Committee with the preparation of the full text, embodying these points, for wide circulation and trial prior to submission to the next Horticultural Congress.

The full text of the revised Code, prepared by the secretary (Stearn) as editor, was circulated early in October 1952 to all members of the joint Committee, including those unable to attend the Congress. Their suggestions were then correlated and sent to an editorial subcommittee with sixteen members, among them R. Ciferri (Italy) and R. Mansfeld (Germany), who were requested to vote for or against each proposal. The Code given below is the final version based on these decisions. It is preceded by a concise version or summary requested at the Congress as a guide to the main provisions of the full Code and prepared by Camp, F. C. Coulter (U.S.A.), Gilmour and Stearn on behalf of the joint Committee.

From the above summary it will be evident that this Code is the outcome of much thought, discussion and correspondence, together with no little expenditure of money and time, by many competent persons in many countries over some forty-seven years. It represents the collective wisdom of persons having a first-hand practical acquaintance with the nomenclatural needs of amateur gardeners, plant breeders, nurserymen dealing in alpines, bulbous plants, herbaceous perennials, trees and shrubs, seedsmen dealing in vegetables and ornamental annuals, agriculturists, foresters, systematic botanists and award-giving and name-registering societies. Much of the work of correlating and tapping this experience has been done during the past three years under the auspices of The Royal Horticultural Society of London, the British Museum (Natural History) and the Academy of Natural Sciences of Philadelphia.

The acceptance of a code depends, in the long run, not upon its origin and history but upon its merits and publicity. It accordingly needs fair trial in many places and over a number of years. The following Code can only achieve the aims set out in its first article, i.e. to promote uniformity, accuracy and fixity in the use of names and to debar or discourage procedures leading to confusion and error, if it is adequately supported and widely adopted. The breeders and introducers of new plants are urged, in their own interest, to give names which are in accordance with the Code. Seedsmen and nursery�men should try to bring their catalogues into line with it. Registering authorities should refuse to register names not in accordance with the Code; no awards should be given to plants not named in accordance with the Code. Specialist societies should use it as a basis for their own codes of nomenclature. Writers on cultivated plants should endeavour to employ only names correct according to the Code; by frequently mentioning the Code as a standard of procedure they will help to make it known and appreciated. Instructors should bring it to the notice of their students and explain its provisions to them. Government agricultural and horticultural departments should take note of its provisions when drafting legislation. By action of this kind its utility and any weaknesses which need emendation will become evident. The Code is, however, provisional in that it can be modified and revised at the next International Horticultural Congress if such genuine trial reveals the need for any changes. Until then the text presented below stands as the official International Code of Nomenclature for Cultivated Plants approved by the 13th International Horticultural Congress. Copyright is disclaimed. Any person, institution or government interested in promoting uniformity, accuracy and fixity in the names of cultivated plants is accordingly welcome to reprint or translate this Code and to give it maximum publicity. Two copies of any such reprint or translation should be sent to the Secretary, International Committee on Horticultural Nomenclature and Registration, c/o The Royal Horticultural Society, Vincent Square, London, S.W.1, England.