CLASSIFICATION | Horticultural Classification Schemes

CLASSIFICATION/Horticultural Classi®cation Schemes

Further Reading Beales P (1997) Classic Roses, 2nd edn. London: Harvill Press. Christ H (1873) Die Rosen der Schweiz mit BeruÈcksichtigung der umliegenden Gebiete Mittel- und SuÈd-Europas. Basel: H. Georg. Darlington CD and Wylie A (1961) Chromosome Atlas of Flowering Plants. London: Allan & Unwin. Graham GG and Primavesi AL (1993) Roses of Great Britain and Ireland. BSBI Handbook no. 7. London: Botanical Society of the British Isles. Henker H (2000) Rosa. In: Conert EI, JaÈger J, Kadereit J, Schultze-Motel W, Wagenitz G and Weber HE (eds.) Illustrierte Flora von Mitteleuropa, vol. IV/2C, LFg. A. Berlin: Verlag Paul Parey. Keller R (1931) Synopsis Rosarum spontanearum Europae mediae. Vol. 65. Denkschriften der Schweizerischen Naturforschenden Gesellschaft, Zuerich. KruÈssmann G (1974) Rosen, Rosen, Rosen. Unser Wissen uÈber die Rose. Berlin: Paul Parey. Saakov SG (1976) Wild- und Gartenrosen. Berlin: VEB Deutscher Landwirtschaftsverlag. Thomas GS (1994) The Graham Stuart Thomas Rose Book. London: John Murray.

Horticultural Classi®cation Schemes T Cairns, American Rose Society, Studio City, CA, USA # 2003, Elsevier Ltd. All Rights Reserved.

Historical Background By de®nition, a species is a population of wild plants similar in characteristics. It is generally recognized that the genus Rosa contains more than 140 different species (see Classi®cation: Conventional Taxonomy (Wild Roses)), typically having ®ve sepals and petals (four of each in one species), abundant stamens and, in the centre of the bloom, numerous styles, each topped by a sticky stigma. Furthermore, when crossed together or when self-pollinated, it produces harmonious progeny. It is the welcome task of humanity to bring order and logic to such a grouping of plants to understand their development and natural evolution. Taxonomy is the scienti®c discipline which concentrates on devising systems of classi®cation. In the botanical classi®cation scheme for the genus Rosa

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as originally de®ned by Rehder (see vol. 3 of this Encyclopedia) and later modi®ed (see Classi®cation: Conventional Taxonomy (Wild Roses)), there are four subgenera ± three very small and anomalous, namely Hulthemia, Hesperrhodos and Platyrhodon, and one major, Rosa, containing the roses proper. While Rosa is divided into 10 sections, three can be regarded as very small and of little importance as far as garden roses are involved. This subdivision within Rosa is based on certain physical parameters (stipules, sepals, blooms, styles, leaves, thorns, etc.). However, the number of chromosomes in the cell nucleus does also provide an important characteristic that can be used in classi®cation. Most wild roses carry 14 chromosomes (i.e. two sets of seven) and are therefore called `diploids'. Roses containing 28 chromosomes are termed as `tetraploid'. Roses with 42 chromosomes are `hexaploid'. Only a few roses have eight sets of chromosomes (i.e. 56) and are called `octaploid'. Hybrids between diploids and tetraploids are triploids with 21 chromosomes (see Genetics: Meiosis). Roses with this odd-numbered set of chromosomes usually lack fertility and do not survive in nature. However, dog roses (section Caninae), which have an unusual mode of inheritance (see Genetics: Inheritance in the Dogrose), include fertile pentaploids. The sections of the subgenus Rosa are listed below (see also Classi®cation: Conventional Taxonomy (Wild Roses)):  Pimpinellifoliae ± about 8±10 species compose this division, with all except two being diploid  Rosa ± one tetraploid species only, R. gallica  Banksianae ± one diploid species only, from China, R. banksiae  Bracteata ± southern North America, R. bracteata and R. clinophylla which are diploids  Caninae ± generally referred to as the dog roses which include tetraploids, pentaploids and hexaploids  Carolinae ± sometimes de®ned as a subsection within the Cinnamomeae  Indicae ± two climbing diploids only, R. chinensis and R. gigantea  Cinnamomeae ± largest section comprising more than 50 diploid, tetraploid, hexaploid and octaploid species from throughout the northern hemisphere, e.g. R. macrophylla, R. moyesii, R. acicularis  Synstylae ± predominantly a large number of white-¯owered, diploid climbers  Laevigatae ± one diploid species from east Asia which has become naturalized in the southern states of the USA.

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Subsequent development and evolution of the species into today's modern garden roses from their primeval ancestors demanded a taxonomic system that incorporated both the old and the new, partially botanically based but with growth habit and plant structure playing an important role. This evolutionary construction is still very much a work in progress. However, some day the family relationships among members of the genus will be disclosed by DNA analysis (see Genetics: Research Trends; Gene Mapping). Until that day, the classi®cation system adopted should re¯ect some scienti®c logic but be clearly overruled by the need to communicate in language suitable to describing the modern progeny in simple easy-to-understand terms. The ideal system for classifying may well be found in a detailed description of the anatomical parts of the rose such as corolla, stigma, style, ovary (petal, disc, stamens, bract, prickle, calyx tube, leaf, lea¯et, auricle, stipule, peduncle, stem, prickles, etc.). Within each of these characteristics a system could be set up with de®nitions of well-recognized shapes. For instance, for the petal shape the following criteria could exist: rounded smooth edges, notched indented or heartshaped, abrupt point at apex, slightly lobed edges, fringed or ruf¯ed edges, blunt, etc. Until such times as there is a marriage between emerging scienti®c data and recognition of plant characteristics, an absolute classi®cation system is beyond our construction, for it will certainly have faults. Evolution of the rose is constantly taking place and the genus Rosa should be capable of accommodating new classes within that framework. For the moment, tolerance must be exercised in the shortcomings of our knowledge base and the hybrid classi®cation schemes adopted to attempt to move forward towards the ultimate goal.

Classi®cation of Cultivated Roses During the last half of the twentieth century an evolution of rose classi®cation schemes took place in an attempt to apply basic taxonomic principles. Such a synthetic separation of similar plants has its limitations since the family tree may be driven not purely by botanical concepts, but by commercial ones. The World Federation of Rose Societies (WFRS), for instance, formulated a family tree based on three distinct groups ± wild roses, old garden roses and modern roses. This system of classi®cation was rudimentary to understand, with major emphasis on recurrent versus nonrecurrent and climbing versus nonclimbing. The recurrent nonclimbing roses represent the majority of modern roses with a subdivision into large, cluster and dwarf ¯owered varieties. However, the application of such a low-resolving-power approach

avoided botanical emphasis and depended on human perceptions. This system, initiated and embraced by the Royal National Rose Society of Great Britain (RNRS), was employed as a fundamental mechanism to describe roses and their growing habit as well as serving as the main criteria for exhibiting roses. However, the terms hybrid tea, ¯oribunda and miniature did exist solely for commercial purposes and communication to the public, but the fundamental concept of grouping on the basis of growing habit dominated. This system was acceptable to most countries of the world and received widespread adoption by breeders and introducers alike throughout the rose world, with the sole exception of the American Rose Society (ARS). This disagreement stemmed from the fact that, in 1955, the ARS was formally designated as the International Registration Authority for Roses (IRAR) and chose to adopt a scheme based on a combination of botanical ancestry and commercial designations for sales. Rose registrations were approved according to this de®ned classi®cation scheme, with 54 different classes and 18 different colour classes. Then in 1989, Jack Harkness was commissioned by the British Association of Rose Breeders (BARB) to propose a classi®cation scheme with improved utilization for hybridizers. The consensus of BARB members was that the existing system was too restrictive and did not allow for expansion to accommodate the latest evolutionary steps in the history of the rose. Jack Harkness developed such an elegant and innovative classi®cation system, based on 30 distinct classes that he had used with great success since 1977 (Table 1). Within this scheme, several new classi®cations appeared that encompassed both classical and modern developments in rose breeding, e.g. Florishrub, Patio, Wichurana Ramber, Wichurana Carpet, Wichurana Shrub, English, Scotch and Sweet Briar. Alas, little attention was paid to this pioneering effort by the nomenclature of®cial bodies to bring common sense to a complex problem. Clearly the success of this system was based upon the improved increased resolving power utilizing ancestry whenever possible, and yet this system was still rejected by the ARS. However, the ®nal consensus chapter in devising a universally acceptable classi®cation during the twentieth century took place in Houston, Texas at the 12th World Rose Convention in 2000. It was at the Classi®cation Committee Meeting chaired by David Ruston of Australia that the new ARS classi®cation scheme was embraced by both the WFRS and the RNRS. This acceptance had been brought about by the recent overtures by ARS towards the WFRS system and the recepetiveness of WFRS towards the main

CLASSIFICATION/Horticultural Classi®cation Schemes

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Table 1 Scheme proposed by Jack Harkness (1989) Number

Class

Botanical af®nity/characteristics/similarity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Species China Noisette Tea Hybrid tea Floribunda Florishrub Miniature Patio Climbing hybrid tea Climbing ¯oribunda Climbing miniature Polyantha Climbing polyantha Hybrid musk Wichurana rambler Wichurana carpet Wichurana shrub Gallica Damask Centifolia Moss Portland Bourbon Hybrid perpetual English Scotch Alba Sweet briar Rugosa

Wild roses `Old Blush' or other early Chinas `Blush Noisette' or a tea-in¯uenced relative thereof Both an early Tea-scented China and a China Tea, but with improved habit and hardiness Hybrid tea, usually with the in¯uence of polyantha Floribunda, but of more spreading growth China, but on a miniature scale Both a miniature and a ¯oribunda Hybrid tea, but of climbing habit Floribunda, but of climbing habit Miniature or patio, but of climbing habit R. multi¯ora as the dominant factor among any other classes present R. multi¯ora as the dominant factor among any other classes present Both a polyantha following the style of Pemberton's hybrid musks R. wichurana or similar species as the dominant factor R. wichurana or similar species as the dominant factor R. wichurana or similar species as the dominant factor R. gallica Gallica, but of more open growth and clusters Gallica and damask, but of more lax growth and more pendulous lea¯ets Centifolias, noticeable glandular growths on the sepals, seed pods Gallica, damask or centifolia on the one side, and to a China on the other Gallica, damask or centifolia on the one side, and to a China or tea on the other Bourbons, representing a progress from them towards hybrid teas Old garden rose on the one side and to a modern rose on the other R. spinosissima (R. pimpinellifolia) R. canina or a similar species on the one side and to an old garden rose R. eglanteria (R. rubiginosa) R. rugosa

ARS reasons for a family tree based on botanical as well as commercial classi®cation systems to blend with the rose registration process.

The ARS Classi®cation Scheme 2000 (of®cially adopted by WFRS for international registration of roses) In 1999 the ARS foresaw the urgent need to bring harmonization to the rose classi®cation scheme and adopted a new family tree incorporating the best ideas from the RNRS / WFRS scheme. As IRAR they approved a new classi®cation scheme that re¯ected both the botanical and evolutionary commercial progress of the rose. There were three main groupings: species (i.e. wild roses), old garden roses (classes in existence before 1867) and modern roses (classes not in existence before 1867). However, several major changes were accepted by ARS. For instance, many of the old garden roses were reclassi®ed as hybrids rather than species, e.g. China to Hybrid China. Within the modern roses, certain ramblers were given a more appropriate family name, Hybrid

Wichuranas (HWich), with a spelling correction committed decades ago. Moreover, the new class of Mini-Flora was introduced to accommodate those plants equidistant from miniatures and ¯oribundas in ¯ower size and growth habit. Then, at the very end of the twentieth century at the WFRS World Convention in Houston, Texas, USA, it was agreed to adopt this new scheme set out by ARS (Figure 1). As always, it was stressed that it was a work in progress. Colour classi®cation The ARS, as the custodian of the registration process, has devised a classi®cation scheme for ¯ower colours that divides the spectrum into 18 distinct colour classes. These colours and their abbreviations, de®ned in Table 2, are also used to describe roses in Modern Rose XI, reproduced in vol. 3 of this Encyclopedia. Species Roses

Often referred to as `wild roses', they are usually single-petalled (four to ®ve petals), once-blooming and have a size range from 60 cm to 6 m. They are

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Genus Rosa

Old garden roses (OGRs)

Species roses

Modern roses

Alba Ayrshire Bourbon and Climbing Bourbon Boursalt Centifolia Damask Hybrid Bracteata Hybrid China and Climbing Hybrid China Hybrid Eglanteria Hybrid Foetida Hybrid Gallica Hybrid Multiflora Hybrid Perpetual and Climbing HP Hybrid Sempervirens Hybrid Setigera Hybrid Spinosissima Miscellaneous OGRs Moss and Climbing Moss Noisette Portland Tea and Climbing Tea

Floribunda and Climbing Floribunda Grandiflora and Climbing Grandiflora Hybrid Kordesii Hybrid Moyesii Hybrid Musk Hybrid Rugosa Hybrid Wichurana Hybrid Tea and Climbing Hybrid Tea Large-Flowered Climber Miniature and Climbing Miniature Mini-Flora Polyantha and Climbing Polyantha Shrub

Figure 1 The American Rose Society classi®cation scheme (2000). Reproduced from Modern Roses XI with permission. Table 2 The American Rose Society classi®cation of rose ¯ower colour Abbreviation

Description

w ly my dy yb ab ob op or lp mp dp pb mr dr rb m r

White, near white and white blend Light yellow Medium yellow Deep yellow Yellow blend Apricot and apricot blend Orange and orange blend Orange-pink and orange-pink blend Orange-red and orange-red blend Light pink Medium pink Deep pink Pink blend Medium red Dark red Red blend Mauve and mauve blend Russet

Reproduced from Modern Roses XI with permission.

listed according to their Latin name, beginning with R. for Rosa, and can have common synonyms, e.g. R. foetida var. bicolor is also known as `Austrian Copper' (see Classi®cation: Conventional Taxonomy (Wild Roses)).

Old Garden Roses

In 1966 ARS adopted the de®nition of old garden roses as referring to those types that existed prior to 1867, the year of introduction of the very ®rst hybrid tea, `La France'. Within this generic de®nition a number of popular subdivisions exist based on natural historical developments and characteristics. The ¯ower form can be quartered, cupped, imbricated or expanded, re¯exed, globular or compact. After an initial spring crop of blooms, some varieties may produce no more ¯owers for the rest of the year but their hip production does add a different kind of beauty to the garden. The beauty of the old garden roses often lies in the heavy fragrance they can impart to the garden. The classi®cations recognized (for botanical af®nities see Harkness descriptions, Table 1) are: Alba Af®nity to R. canina and R. damascena or R. gallica. Once-blooming. Known as `white roses', these plants are upright, often climbing, dense blue-green foliage and disease-resistant. Highest-rated member is `White Rose of York'. Ayrshire Developed from R. arvensis. A group of climbing, sprawling roses that originated in Scotland. Once-blooming.

CLASSIFICATION/Horticultural Classi®cation Schemes

Bourbon First repeat-¯owering roses developed from the Hybrid Chinas. They derive their name from the location of the ®rst members of the class, the Ile de Bourbon in the Indian ocean. Plant size can range from 60 cm to 4.5 m tall. Repeatblooming. Boursault A small group of thornless rambling-type roses developed by the French gardener who gave his name to the class. Once-blooming. Centifolia (Provence Roses) Not a true species as once, but a complex hybrid of R. gallica, R. phoenicia, R. moschata, R. canina and R. damascena. These Dutch hybridized roses derive their class name from the fact that the ¯owers often contain over 100 petals. Plants are 120±240 cm tall and winter-hardy. They are also referred to as `cabbage roses', featured in Dutch ¯ower paintings of the seventeenth century. Developed mainly by the Dutch in selecting improved strains of R. centifolia. Once-blooming. Damask These roses brought by crusaders around the thirteenth century from the Middle East are best known for their intense heavy fragrance and recurrentblooming and prized for their fragrance. `Autumn Damask' was highly characteristic of this class. Plants are generally in the size range of 1±2 m. Some varieties are repeat-blooming. Hybrid China Plants are generally small, ranging from 60 cm to 1 m tall. Stems are often too weak to support fully the clusters of blooms which have a spicy fragrance. Plants are not hardy and require winter protection in cold climates. Repeat-blooming. Hybrid Gallica Af®nity to R. gallica. Plants are small (1±1.3 m tall), fragrant, winter-hardy and come in brilliant colours. Once-blooming. Hybrid Perpetual Popular during the nineteenth century, this group of roses is characterized by repeat blooming, size (about 2 m tall upright plant), fragrance and colour range (mostly pinks and reds). Moss Serendipitous breeding from a sport of a R. centifolia. Named for the mossy thorn growth on the peduncle just below the bloom and sepals, this group releases a pine-scented oleoresin when the moss is rubbed between the ®ngers. Plants are generally winter-hardy and 1±2 m tall. Some varieties are repeat-blooming. Noisette This classi®cation originated in the USA by Philippe Noisette of Charleston, South Carolina,

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who later introduced them in France when he moved there in 1817. Plants are large and sprawling, often reaching up to 6 m tall. Blooms are produced in fragrant clusters. Portland This small group of plants derived from crosses involving hybrid Gallica, Damask, Centifolia and Hybrid China are small in stature (usually 1.3 m tall), repeat-blooming and have very short peduncles. Class named in honour of the Duchess of Portland. Tea Characterized as small to medium-sized plants (1.3 m tall), they have large blooms on weak stems, which cause the ¯owers to droop. Flower form is symmetrical and the forerunner of modern hybrid teas. Modern Roses

The era of modern roses was established in 1867 with the introduction of the ®rst hybrid tea, `La France' by the French breeder, Guillot. This variety was considered unique for a number of important horticultural reasons. One, it possessed the general habit of a Hybrid Perpetual as well as the elegant shaped buds and free-¯owering character of a tea rose. By the late twentieth century, more than 10 000 hybrid teas has been bred with great success. Introduction of `La France' heralded the era of modern roses. Breeders were quick to recognize that planned parenthood could evolve new ¯ower forms and size, growth habit and colours. Therefore, the following new classi®cations based on growth habit evolved. Floribunda and Polyantha Second only to the hybrid tea and Grandi¯ora in popularity, the ¯oribunda is characterized by its profuse ability to bear ¯owers in large clusters or trusses with more than one bloom in ¯ower at any one time. This class is unrivalled for providing massive colourful displays which are longlasting for garden display. The distinct advantage of the ¯oribunda is its ability to bloom continually, whereas the hybrid tea exhibits a bloom cycle every 6±7 weeks. The ¯oribunda as a class are hardier, easier to care for and more reliable in wet weather than their hybrid tea counterparts. Polyanthas are generally smaller but sturdy plants with large clusters of small 25-cm-diameter blooms, often used for massing, edging and hedges. Hybrid Tea and Grandi¯ora Perhaps the most popular class of modern roses is the hybrid tea, easily recognized by the large, shapely blooms containing

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CLASSIFICATION/Horticultural Classi®cation Schemes

30±50 petals. Flowers are borne on long stems, either singly or with several side buds. In 1945, the `Peace' rose heralded the modern era of the elegantly formed hybrid teas. So dramatic was the overwhelming public acceptance and praise accorded this variety that its place in history was instantaneous. Since 1945, many thousands of new hybrid teas have been bred and introduced. In 1954, the introduction of a rose bred from crossing the hybrid tea, `Charlotte Armstrong', with the ¯oribunda, `Floradora', resulted in a carminerose and dawn-pink variety displaying not only the characteristics of a hybrid tea but also the ability to bear clusters or trusses and grow to a commanding height of 2±3 m or more. To accommodate this variety, the class of Grandi¯ora was born and `Queen Elizabeth'1 had the distinction of being the very ®rst member of this class. Large-Flowered Climber and Hybrid Wichurana These varieties are dominated by their growth habit, longarching canes with the ability to climb (if properly trained and tied) up fences, over walls, through trellises, arbors and pergolas. These varieties offer a wide range of ¯ower form, shape and colour. Shrub (Classic and Modern) Shrubs are easily characterized by their sprawling habit. There are ®ve popular subdivisions within the class: Hybrid Kordesii, Hybrid Moyesii, Hybrid Musk, Hybrid Rugosa and Shrub. They can grow from 1.5 to 4.5 m or more in every direction given the correct climate and growing conditions. Noted for their hardiness, they are usually vigorous and produce large quantities of clusters of ¯owers. The unique group of roses hybridized by David Austin (often called English roses) belongs to this class. They resemble old garden roses in shape and form but are recurrent-bloomers and have fragrance. Miniature and Mini-Flora These classes have increased in popularity due to their novelty and versatility. They can be used for edging beds, growing in containers and rockeries or even for taking indoors as temporary pot plants for decoration. The height of the average plant is about 35±75 cm and ¯ower form and foliage are indeed miniature versions of both hybrid tea and Floribundas. Mini-¯ora roses are a new classi®cation adopted by the ARS in 1999 to recognize another step in the evolution of the rose, i.e. intermediate in bloom size and foliage between miniatures and Floribundas.

Rose Registration Process Pivotal to developing an appropriate classi®cation scheme is the intelligent collection of detailed descriptions of characteristics such as ¯ower colour, petal number, bloom size, fragrance, blooming habit, prickles, foliage, growth habit, and, most of all, accurate parentage. That process has already been begun by ARS in the rose registration process (see Modern Roses XI, pp. xviii±xix). Moreover, the widespread use of DNA analysis may reveal more de®nitive relationships which are as yet undiscovered. Today, however, there exists some confusion in the minds of average rose growers throughout the world as to why two different rose varieties with exactly the same name can be sold. The reasons are simple. Most breeders prefer to register their roses of®cially using a unique generic variety denomination. That denomination is often a name, dif®cult to pronounce, constructed according to the code system supported by Communaute Internationale des Obtenteurs de Plantes Ornementales et FruitieÁres de Reproduction AsexueÂe (CIOPORA). At the same time the breeder makes a formal announcement of the intended fancy commercial names under which the variety will be sold. Unless those fancy names are trademarked, there is no legal protection against using such a fancy name over and over again. For instance, Kordes in Germany has introduced `Valencia'1 and `Liebeszauber' several times decades apart, as is their right! In the twenty-®rst century, however, there is comfort in the knowledge that the naming and protecting of variety denominations has quickly evolved by taking a few giant steps in the right direction. While the solution to preventing two roses with the same fancy name from occurring again is by no means completely resolved, the designation of the variety denomination for registration purposes should help proper identi®cation. To understand this tale of nomenclature, the following brief explanation should assist the reader in the complexities of the process of naming to preserve valuable data for future generations of rose growers. History of rose registration In 1913 the ARS pioneered the process of recording new rose varieties from all over the world as a means of harmonizing nomenclature. By 1916 it had successfully promulgated registration guidelines and began the long tradition of publishing such registrations. In 1921 the American Rose Annual contained a feature section called `New Roses of The World' which has continuously appeared every year into the modern era. Then in 1930 the late Dr J. Horace McFarland, then Editor of

CLASSIFICATION/Horticultural Classi®cation Schemes

the Society's publications, began to compile lists of rose names and descriptions which he published under the title of Modern Roses. Each subsequent edition of Modern Roses built on the initial policies and procedures of including only those varieties currently in cultivation. In the 1958 edition, Modern Roses V, the goals had been enlarged to include all the names of species and varieties presently in cultivation or of current interest, together with many varieties of historical and botanical importance. However, all editions up to and including Modern Roses X have been published strictly using the fancy name for intended use by American rose growers. Names were always directly applicable to the USA while the rose might enjoy other names in other countries. For instance, `Peace' was the fancy name in the USA while in France it was called `Mme A. Meilland', in Germany it was sold under the name `Gloria Dei' and in Spain `Gioia'. These other names are often referred to as synonyms. Unless protected by trademark or registered, the names could in theory be used by another grower or introducer. So today many breeders rely heavily on trademarks to protect the assigned fancy names of their roses. Without such protection the names could be reused in the commercial environment. A good example of this situation is the name `Lady in Red'. Originally registered as a miniature rose with IRAR, the name has recently been reused to describe a new red hybrid tea by Jackson & Perkins for sale in New Zealand. With the growing popularity of roses throughout the world, the 14th International Horticultural Congress (IHC) meeting in Scheveningen, The Netherlands, in 1955 appointed the American Rose Society as IRAR. This act by the IHC was a solid declaration of the need for a single central focus for the registration system to prevent duplication of variety denominations. ARS subsequently accepted the role and, more importantly, the responsibility and implementation. It was clearly stated for `the good of the industry and botanical and horticultural science that all hybridizers or nurserymen register the names of their roses with one of the many National Registration Centers' set up in association with various national rose societies. During the years since 1955 the ARS has continued to approve the registration of a variety denomination, ensuring that no duplication was permitted. However, as the regulatory authority, ARS had no compliance or enforcement policy should an independent grower wish to market a rose under a name already registered but unprotected. Around 1958 it became apparent that regulating the name of the rose was a much more complex process. In spite of guidelines and controls, there still existed the

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possibility that different roses with the same name could be sold to the public. On this occasion, the breeders took matters into their own hands and developed a simple system of unique coding to avoid duplication, at least in the registration process. Code names were simply a combination of the ®rst three letters of their name or company in capital letters followed by some additional letters, usually derived from the slang name given the rose during its evaluation before introduction. In this way it became easy to identify the roses from a speci®c breeder, for example KOR for Kordes in Germany, MAC for McGredy, HAR for Harkness in the UK, MEI for Meilland in France and SIM for Nola Simpson from New Zealand. While such code names were included in registration submissions for approval by ARS, they were not included with the descriptions of roses in Modern Roses until the edition published in 1986. In 1978 the Convention of the International Union for the Protection of New Plant Varieties in Geneva, Switzerland voted for the notion that each new rose variety registered be given a unique descriptor, the code name, to identify clearly the plant whatever the ®nal name given the rose for sale to the public. This code name was intended to become the designated variety denomination within the formal registration process. In 1981 the ARS was appointed to serve as the Registrar for CIOPORA. Then, in 1985, the US Patent and Trademark Of®ce proposed rule making in the Federal Register to implement the consensus reached by the Convention in Geneva. However, they fully intended to adopt the registered names listed in the latest edition of Modern Roses which, in many cases, were popular fancy commercial names and not the unique variety denomination (i.e. usually the code name). To correct this situation, the ARS in combination with American growers and CIOPORA moved to change the registration strategy by declaring the code name as the variety denomination. Within this agreement the breeders agreed that they would indicate on the registration application which cultivars were patented or trademarked under a fancy name. The new registration form was approved for use in January 1998. For the future In the registration of a new variety, the unique code name will automatically become the variety denomination. For most registrations, this guideline will be directly applicable. In most instances, when an amateur breeder registers a rose, the lack of a code name places the given fancy name as the variety denomination. Trademarks under which the variety enters commerce will be annotated only at the request of the breeder. However, it is

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routine collection of exact data on each cultivar that will serve the purpose of improving the current classi®cation system.

Conclusions Classi®cation of roses has long been a topic for discussion as to how best to preserve the botanical signi®cance and yet ful®l a commercial bene®t to the public. On the international scene, there is no doubt that common sense prevails in assigning classes based on several basic principles, such as climbing versus nonclimbing, recurrent versus nonrecurrent. This grand design accommodates cultivated roses in a clean subdivision that leaves no doubt as to the growth habit of the cultivar. For commercial purposes, however, the public need an identi®able class to connect with. Introducers and hybridizers have been innovative in introducing new classes to describe their efforts. For instance, Floribunda and Grandi¯ora were American inventions to capture the growing habits of new types of roses. This system becomes a necessity within the trade to communicate easily with the potential buyer. In the registration process delegated to ARS, introducers have the option to use such classes, as approved by ARS, in their submissions to describe in simple terms what type of rose they have hybridized, irrespective of its parents and heritage. At the present time, however, there exists some confusion in that the registration data may not re¯ect how the rose is actually being sold. Any classi®cation system must recognize the importance of the hybridizer/introducer and the rose-growing community. Hopefully, the recent consensus reached to bring common sense and logic to this important aspect of roses is practical. The evolution of the rose into many new ¯ower forms and growing habits should be accommodated by a classi®cation system that is ¯exible and is a re¯ection of reality. See also: Classi®cation: Conventional Taxonomy (Wild Roses). Genetics: Meiosis; Species Crosses; Inheritance in the Dogrose; Gene Mapping; Research Trends. History of Roses in Cultivation: European (Pre-1800); Modern (Post-1800).

Further Reading Allen EF (1972) A Simpli®ed Rose Classi®cation for Gardeners. St. Albans, UK: Royal National Rose Society Annual. Cairns T (2000) Modern Roses XI. London: Academic Press. Lammerts WE (1945) Scienti®c Basis of Rose Breeding. Shreveport, LA: American Rose Society. Rehder A (1940) Manual of Cultivated Trees and Shrubs Hardy in North America. 2nd edn. New York.

Cultivar Identi®cation by Image Analysis D Zhang, Geves Le Magneraud, F-17700 SurgeÁres, France M-H Gandelin, Geves Cavaillon, Les VigneÁres, France # 2003, Elsevier Ltd. All Rights Reserved.

Introduction Rose breeders need to protect their intellectual property rights for their new varieties. This requires an accurate description of varieties. In the process of protecting new plant varieties, all applicant varieties must undergo tests of distinctness, uniformity and stability (DUS) according to the Union pour la Protection des Obtentions VeÂgeÂtales (UPOV) convention. The assessment of the distinctness of a new variety is based on the investigation of 46 phenotypic characteristics listed in the Guidelines for the Conduct of Tests for Distinctness, Homogeneity and Stability of roses established by UPOV. All the observations made on these 46 characteristics fall into three categories: behaviour (development type), morphology (size, form) and ¯ower colour. The principal weakness of this system is the lack of precision and subjectivity of the observations. For example, the size of petal should be assessed as `very small, small, medium, large and very large' according to the UPOV guidelines for roses. With the increasing number of protected varieties of roses in the world, this becomes insuf®cient for accurate cultivar identi®cation. This is why new techniques and descriptors are being explored for cultivar identi®cation in roses. Image analysis is one of the new tools which can allow an automated numeric description of different organs of roses; this may make the description of rose morphology and ¯ower colour more precise, objective and reliable, adding to the human investigations in the ®eld or greenhouse.

Materials Necessary for Image Analysis Flowers, petals, leaves and lea¯ets can all be used for image analysis in rose. In the present article, only ¯owers and petals will be considered. The sampling can be made on plants cultured in a greenhouse or in the ®elds. In order to assess the variability within a cultivar, the study should be performed on several plants per cultivar, several ¯owers per plant and several petals per ¯ower, over several years and several seasons, including ¯owerings in greenhouse and ®eld. In Geves Sophia-Antipolis, we used a colour scanner Sharp JX450, with a resolution of 100 dpi (digit per inch ˆ 4 pixels per millimetre), to acquire images of