HORTAX NEWS Vol 1, Part 1 - 10 December 1993

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HORTAX Members' Notes and News Brief notes on the current activities of HORTAX members. Crinan Alexander is horticultural taxonomist at the Royal Botanic Garden, Edinburgh and has recently returned from the RBG expedition to China. He is just starting to monograph old-world Ribes. Susyn Andrews looks after horticultural classifications at the Royal Botanic Gardens, Kew and still finds time to work on her Ilex monograph. Christopher Brickell has now retired as Director General of the Royal Horticultural Society. We wish him well as he gets back to "real work", writing and, we hope, doing some horticultural taxonomy! Allen Coombes is the botanist at the Sir Harold Hillier Arboretum. He has revised the Hillier Manual of Trees and Shrubs and has recently returned from a plant-hunting trip to Edwards Plateau in Texas. Sabina Knees is now Secretary to the European Garden Flora project. We eagerly await volume 4 of this important work at the next Chelsea Show. Earlier this year she undertook a plant-hunting trip to Chile. Alan Leslie is the Registration Officer for the Royal Horticultural Society's many International Registration Authority responsibilities. He is also co-proprietor of the well-known Monksilver Nursery (whose catalogues are much admired as examples of what nurserymen could do!). Tony Lord continues his fine work as editor of The Plant Finder. He is also writing a major work on the historical and aesthetic use of borders. Victoria Matthews has left her seven year stint as editor of the Kew Magazine to become the editor of the New Plantsman to be launched by the Royal Horticultural Society next Spring. A truly exciting project. Diana Miller is in charge of the Royal Horticultural Society's herbarium at Wisley. She also continues to maintain her special interest on the horticultural taxonomy of Pelargonium. Charles Nelson is the horticultural taxonomist at the National Botanic Gardens, Glasnevin and regularly publishes on the wild and cultivated plants of Irish origin. His other interests include history and bibliography. Piers Trehane spends most of his time at work on his Index Hortensis project. As part of this work, he is currently researching the use of trademarks and plant patents and takes an interest in legislative matters. Adrian Whiteley is a botanist at Wisley with a special interest in house plants.

HORTAX NEWS Vol 1, Part 1 - 10 December 1993

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The Joy of Ex An invited contribution from Graham Rice The use of "ex" could be used to cover three main areas which indicate that the material in question may not be true to name in so far that the uniform characteristics expected from the original cultivar may not be apparent or may be variable. The sexual propagation of clones. Example: by writing Crocosmia ex 'Lucifer' one indicates that the material derived - seed or seedlings - was taken from the female parent (the clone 'Lucifer') by uncontrolled open pollination (selfing and outcrossing) and that the resulting plants will be variable. The uncontrolled sexual propagation of seed races originally produced under controlled conditions. Example: by writing Pelargonium × hortorum ex 'Hollywood Star' one indicates that the progeny is derived from the uncontrolled sexual propagation of a cultivar that is normally maintained as a uniform seed race - in this case an F1 hybrid. The derivation of material from the sexual propagation of cultivars forming part of a non-hybrid uniform seed race. Example: by writing Antirrhinum ex 'Black Prince' one indicates that although 'Black Prince' is an open-pollinated seed race, in which rigorous selection and roguing ensures its uniformity, plants derived from uncontrolled selfing and outcrossing are variable. This need not apply to cultivars which are generally 100% self-pollinating in the field such as Lathyrus odoratus cultivars. The Editor comments: Graham Rice is a well-known British horticultural journalist with a special interest in annuals and bedding. I know that a small number of reputable seed distributors already use this sort of convention in an informal way to state that their seed may not come "true", yet by using this device they indicate the name of the mother-plant. Perhaps the revised Cultivated Code should pay more attention to demonstrating solutions of this nature that so the world may adopt similar conventions universally. Incidentally, I have seen "ex" being used to indicate that a cultivar comes from a particular locality - using its literal latin meaning "from".

HORTAX NEWS Vol 1, Part 1 - 10 December 1993

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Solutions to some species/cultivar problems With the advent of the term Cultivar it was at last possible to distinguish plants at a horticultural level without giving them botanical status. Prior to this, in order to distinguish any particular form it had been necessary to assign it to one of the available botanical ranks such as variety, and many plants that today are regarded as cultivars were originally described at botanical level. It is acceptable, and indeed desirable, under the current code that the names originally applied to these plants are retained and used at cultivar level. An example of this is the Lucombe Oak, which is now regarded as a cultivar (Quercus × hispanica 'Lucombeana') although it had been treated by Rehder as a variety - Q. × hispanica var. Lucombeana (Sweet) Rehder. In most cases the change in status to cultivar causes no problems. It is generally fairly obvious which plants are garden selections and they are then treated accordingly. In a relatively small number of cases, however, there has been a great deal of confusion leading to different methods of treatment by different authors. This situation occurs when a species was originally named from a plant which is, in effect, a cultivar. In some cases further confusion was caused when the normal or wild form was named later to distinguish it from the garden plant which formed the type. Two good examples of this are provided in the genus Viburnum. V. plicatum was named from the sterile-flowered "snowball" plant found in a Japanese garden. Although the wild plant with normal flowers was named first as V. tomentosum this name is illegitimate, having been used earlier for V. lantana. Most current works restrict the use of the specific name to the cultivated snowball-flowered plant while referring all wild plants and other garden selections to f. tomentosum. This situation is clearly similar to the example in Quercus, cited above. However, in this case we have a much less satisfactory outcome - a naturally occurring plant has been given botanical status in order to distinguish it from a cultivar. There are several factors that might be taken into account in order to solve this problem. Does the sterile-flowered plant occur in the wild? Is there more than one clone of it? In fact these questions are completely irrelevant. The only one that we need ask ourselves at this stage is: Do we wish to distinguish these taxa at botanical level? The answer in this case is clearly no, as one plant is only a garden selection of the other. Having come this far we can then proceed to determine the correct names for these plants. The correct name for the species (Viburnum plicatum) must, of course, stand. However, having decided that we no longer wish to distinguish the sterile form botanically, we can state that the name V. plicatum includes both this and the naturally occurring form of the species. V. plicatum f. tomentosum therefore becomes a synonym of V. plicatum. All that then remains is to provide a cultivar name for the sterile-flowered plant previously known simply as V. plicatum. As the type specimen of the species is from the sterile-flowered form it is not possible to distinguish this at any botanical level, it always remains as V. plicatum whatever other taxa are recognised botanically within the species. However, the naming of a cultivar is quite different. When a new cultivar is named it is not necessary to compare it to the botanical type specimen of the species, indeed there is no objection to giving cultivar status to plants from which the botanical type came. In effect, that is what needs to be done in this case. A suitable epithet is already available as the sterile plant was named as var. sterile K. Koch. 'Sterile' can therefore be adopted as the cultivar name and the synonymy becomes: V. plicatum Thunberg; V. tomentosum Thunberg ex J.A. Murray, not Lamarck, V. plicatum g. tomentosum (Thunberg ex J.A. Murray) Miquel, V. plicatum f. tomentosum (Thunberg ex J.A. Murray) Rehder V. plicatum Thunberg 'Sterile'; V. tomentosum b. sterile K. Koch In the above and following examples, synonyms are given for clarity under cultivars. These synonyms are also, of course, synonyms of the specific name as a whole, which is implied as a cultivar has no botanical standing. An almost identical situation occurs with Viburnum macrocephalum and this can be treated as follows: V. macrocephalum Fortune; V. keteleeri Carrière, V. macrocephalum f. keteleeri (Carrière) Rehder V. macrocephalum 'Sterile'; V. macrocephalum a. sterile Dippel There are undoubtedly many other plants to which the situation above will apply, however in each case it will be important to examine the taxonomy and nomenclature of the plants involved in order to resolve their naming. A genus that may create particular problems is Hosta and the naming of H. sieboldii is examined in the next example. Hosta sieboldii was named from a garden plant with white-margined leaves. Current treatments of the genus tend to include both white-margined and wholly green-leaved plants under the name H. sieboldii. While this is satisfactory botanically it is not acceptable on a horticultural level, as while H. sieboldii of gardens will generally be the variegated plant, H. sieboldii from its native populations in Japan is most likely to be green-leaved. W. George Schmid in The Genus Hosta, (1992) states that "Virtually all the wild population is all-green... but the white-margined form, which is uncommon in the wild, was the first representative of this species to be validly published by Paxton... The white-margined type does not come true from seed and is nonperpetuating in the wild, so it is technically a mutant form which should be reduced to cultivar form." After coming so close to resolving the problem Schmid unfortunately decided to follow "all previous authors." Clearly, however, the variegated plant needs a name to distinguish it in gardens from other forms of the species i.e., it should be treated as a cultivar. Until recently, H. sieboldii was widely known under the synonymous name H. albomarginata. The obvious solution in this case, therefore, is to retain the well-known epithet albomarginata and to use it at cultivar level for the commonly grown form of the species, whether it is a single clone or a group of similar clones. The synonymy then becomes: Hosta sieboldii (Paxton) Ingram Hosta sieboldii 'Albomarginata'; H. albomarginata (W.J. Hooker) Ohwi Allen J. Coombes   The Editor comments: Whereas many will agree that it is useful to be able to separate the cultigenic type from the species for horticultural purposes, not everyone will be happy with this solution. Using one of Allen's examples, many will say that Hosta sieboldii is variegated and that that is that, and ignorance of the fact is just too bad. Others will recognise that H. sieboldii sensu lato contains a range of forms and that specifically it is H. sieboldii var. sieboldii (i.e. in the narrow sense) that is variegated. The more "correct" cultivar name would thus be H. sieboldii 'Sieboldii' but this seems to me to be visually confusing in the extreme. One must be careful not to disrupt the type/autonym method and the cultivar epithets proposed by Allen are based on illegitimate names and are, I suggest not eligible for transfer to cultivar status. (The Viburnum epithets 'Sterile' come from superfluous names and the Hosta example features a later homonym). There are a number of species whose name is founded on a cultivar but which contain other naturally occurring taxa and I propose that the problems of separation for horticultural purposes is done consistently by a suggested convention demonstrated below. The following new cultivar names are here proposed for those cultivars which equate to the autonyms indicated. Viburnum plicatum 'Thunberg's Original' V. plicatum Thunberg, forma plicatum sensu auct. Viburnum macrocephalum 'Fortune's Original' V. macrocephalum Fortune, forma macrocephalum sensu auct. Hosta sieboldii 'Paxton's Original' H. sieboldii (Paxton) Ingram forma sieboldii sensu auct. Hemerocallis sieboldii Paxton Notice that I have based the cultivar name on the name-bringing author. If the author citation for V. plicatum was Thunberg ex J.A. Murray (which it is not), I would still have used Thunberg's name here. I suggest that careful bibliographic research must be undertaken before such solutions are published. Some slight adjustment to this proposed convention may be required if say, Thunberg had proposed two species names based on cultivars within the same cultivar class (i.e. usually the genus) but that should not be a difficult problem to overcome if it arises. I have yet to find an example. The format suggested seems to work: people can see what is going on and the type/autonym-method is not totally undermined. A few name changes will be required (we all try to avoid those) but this "downside" seems to be outweighed by the resulting clarification. Comments relating to this problem and information on any further plants which fall into this category would be most welcome.

HORTAX NEWS Vol 1, Part 1 - 10 December 1993

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Correcting cultivar names: how far should one go? As a general rule-of-thumb it is the RHS practice in cultivar registration that when a new cultivar name incorporates the name of the parent cultivar, but the latter is misspelt by the later author, then the spelling of the new cultivar is treated as an orthographic error and corrected. Only if it can be shown that the author deliberately adopted a different spelling should the new version be retained. At least two queries arise from this. Is it right to let a later author create confusion by misquoting the parental name even when it is a deliberate choice? It can only lead to doubt ever after about the new cultivar name. (The argument here is solely over the incorporation or parental names and it is not sought to extend this to other situations) What should the response be when a generally used spelling for a cultivar is shown to be incorrect and that the misspelt name has been incorporated in several other cultivars (which may have arisen as sports from the original)? Is this another example of the case above or is the fact that the error was not the later author's significant? Can he be said to have "deliberately" used the "incorrect" spelling? Should all the derived names change when the error is discovered? Chamaecyparis lawsoniana 'Alumii' is a case in point. This is the correct, original spelling and has been widely used in continental Europe. In the UK and USA on the other hand, 'Allumii' has been almost universally employed and cultivars such as 'Allumii Aurea' based upon that spelling. Comments please! Alan Leslie   Editor's Note: Alan is the Registration Officer for the Royal Horticultural Society's numerous responsibilities as an International Registration Authority. The Society is IRA for some enormous groups such as Dahlia, Delphinium, Dianthus, Lilium, Narcissus, Rhododendron, Orchids and Conifers so Alan probably has more experience than anyone else in this particular and important area of stabilisation of names.

HORTAX NEWS Vol 1, Part 1 - 10 December 1993

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That Multiplication Sign The HORTAX submission for the proposed revision of the ICNCP indicates that in both hybrid formulas and hybrid names there should be a space on either side of the multiplication sign or lower case "x", whichever is employed. For the ICNCP to remain in harmony with the ICBN the latter would thus have to be amended, as its Recommendation H3A does not sanction a space after a multiplication sign. Ed Voss (in litt. 8/7/1992) has expressed his "greatest horror" at this proposal advancing the following reasons for maintaining the status quo: it would look very silly to change it would be confusing since in a formula the multiplication sign (or lower case "x") can be read as "crossed with", whilst it does not mean this when placed in front of an epithet there is potentially a confusion in a case such as Rhamnus × Frangula which could be interpreted as either a hybrid generic formula or the species R. Frangula treated as of hybrid origin. (NB the deliberate and legitimate use of a capital letter for a specific name derived from another genus - ICBN Recommendation 73F) None of these reasons is convincing. This is not an especially fundamental proposal and neither Code is cast in stone. Considerable changes in many areas have been assimilated over the years without too much loss of face. Indeed it would be even sillier not to accept what is general practice than to try and maintain a discipline that is not understood between × and "x"! Most users are not nomenclaturists and frankly don't worry about such apparent trivialities. What is wanted is a simple uncomplicated system which is used in the same way in each and every case. Since the lower case "x" (plus a following space) is already permitted by the Code in a hybrid name, there will be no more confusion than there is now if a space is also permitted after the multiplication sign: less if anything as it will not seem to point to two different meanings. The context in which the "x" or × is used will usually make it quite clear whether it can be interpreted as "crossed" or not. The example quoted involving Rhamnus and Frangula is not impossible, even if rather improbable, but any potential ambiguity which the context does not immediately make clear would be removed by insisting that all epithets start with a lower case letter. Rhamnus x Frangula would thus be clearly distinguished from Rhamnus x frangula. Here is another case where a single, simple rule, without exceptions, should be championed. Forget grammatical niceties and operate a clear consistent policy. A few may have apoplexy at such an approach, most will go away rejoicing! Alan Leslie   Editor's note: With Rhamnus subgenus Frangula (P. Miller) Dippel appearing to be monophyletic (See: Flora Neotropica 20:3 (1978), this example is not as far-fetched as it may sound!

HORTAX NEWS Vol 1, Part 1 - 10 December 1993

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Standard Specimens and Standard Illustrations The HORTAX proposal for revision of the Cultivated Code left the consideration of Standard Specimens unfinished. What follows here is an outline proposal worked-up by the editor of HORTAX NEWS. It has not been discussed in depth at a HORTAX meeting and is here presented for international discussion and comment. The outline is presented along with proposed terminology and acronyms. Suggestions for improvements (or abolition!) will be gratefully received.   Introduction A cultivar epithet needs to be anchored to a particular plant specimen to help avoid duplication of names and to make clear exactly what is meant by that name. Under the Botanical Code, new names are so fixed by the application of a nomenclatural Type which accompanies the description of a new taxon. This Type has to be nominated as part of the conditions effecting valid publication of a Latin name so that future workers can see exactly what the original name-giver had in mind when describing that taxon. These strict rules are not required for cultivars; however, the stability of cultivar names is enhanced by the designation of a Standard Specimen or Standard Illustration. Note: It should be remembered that many cultivars have variable characteristics within their circumspection and any reference to a Standard Specimen or Standard Illustration in determining the identity of a plant must be done with this knowledge. In theory, only clones may be identified and named by direct comparison with a Standard Specimen or Standard Illustration although it should also be realised that even these may show movement of characteristics over a period of time (in which case they probably warrant a new epithet). Standard Specimens The Standard Specimen of a cultivar is the (usually dried) herbarium specimen to which the cultivar epithet is permanently attached, whether as a correct name or as a synonym. Standard Specimens must be expertly prepared and raisers of new cultivars are strongly advised to donate plant material to a recognised herbarium so that suitable specimens may be prepared. It is essential that donors inform the receiving herbarium whether the cultivar is clonal or seed-raised. Herbaria may, at their own discretion, accept Standard Specimens from third parties. A Standard Specimen should show all the characteristics that makes the cultivar distinct from any other plant. Standard Illustrations A Standard Illustration may be designated in place of a Standard Specimen when diagnostic characteristics are best recognised from a suitable illustration. Example: The particular flower colours of Dianthus and Narcissus cultivars might be better observed in paintings or photographic transparencies rather than in dried herbarium specimens. Forms of Standard Specimens and Illustrations There are different kinds of Standard Specimens and Illustrations: An Original Standard Specimen (OSS) is the one herbarium specimen cited by the author of a cultivar epithet when publishing a full description of that cultivar. Example: When P.C. De Jong first described Betula utilis 'Doorenbos' (in Dendroflora 23:26 (1986)) he cited the herbarium specimen De Jong 1205 in Utrecht Herbarium and this is to be regarded as the Original Standard Specimen. An Original Standard Illustration (OSI) is a photograph or other illustration cited by the author of a cultivar epithet when publishing a full description of that cultivar. A Statutory Standard Illustration (SSI) may be designated when cultivar epithets are published by statutory authorities as part of a legal process. Any photographic or other illustration relating to that process is automatically the Statutory Standard Illustration for that epithet and takes precedence over any other Standard Specimen or Illustration. A Substitute Standard Specimen (SSS) is a specimen selected to serve as a Standard Specimen when all of the material on which the cultivar epithet was based is missing, lost, damaged beyond use, or destroyed. Note: Before designating a Substitute Standard Specimen for a cultivar, enquiries should be made at other herbaria to ensure that suitable original material no longer exists. Note: If a Substitute Standard Specimen is chosen from a Duplicate Standard Specimen, care must be taken to ensure that the plant material has in fact, been taken from the same plant. A Duplicate Standard Specimen (DSS) is any duplicate herbarium specimen of the Original or Substitute Standard Specimen taken from the same cultivar. Note: It is strongly recommended that Duplicate Standard Specimens are distributed to other major horticultural herbaria, especially those in other countries. Concurrent Standard Specimens (CSS) exists when more than one herbarium specimen exists for the same cultivar (for example, fruits might be kept in a preserving jar separate from the respective herbarium folder). Concurrent Standard Illustrations (CSI) exists when two or more illustrations have been simultaneously published by an author (for example showing flowers, fruit or autumn colour on different plates). A Type Standard Specimen (TSS) exists when a cultivar epithet is based upon a validly published Latin epithet: the Standard Specimen is automatically equivalent to the Type of that name, if the Type is a herbarium specimen. Example: Cotoneaster 'Watereri' is the clone upon which the hybrid binomial Cotoneaster x watereri was based by A.W. Exell (in The Gardener's Chronicle, 1928:44 (1928). The Type for Exell's name is the specimen at The British Museum (Natural History) and this is automatically the Standard Specimen for the clone C. 'Watereri'. A Type Standard Illustration (TSI) exists when a cultivar epithet is based upon a validly published Latin epithet: the Standard Illustration is automatically equivalent to the Type of that name, if the Type is an iconotype. Example: The cultivated plant known today as kohlrabi (Brassica oleracea var. gongylodes of Linnaeus) was lectotypified in accordance with the Botanical Code by E.H. Oost et al. in the Botanical Journal of the Linnaean Society 101:344 (1989) to plate 251 in P.A. Mattiolus's De plantis epitome utilissima published in 1586. This automatically serves as the Standard Illustration when kohlrabi is equated to Brassica oleracea 'Gongylodes'. Example: Aesculus pavia 'Humilis' was first described by J. Lindley as A. pavia var. humilis in S.T. Edwards's The Botanical Register accompanied by plate 1018 (1826). Assuming this equates to the modern concept of a cultivar, and in the absence of suitable herbarium Type material, this illustration might be designated as the Standard Illustration. An Improved Type Standard Specimen (ITSS) may be designated when the Type of a name serves little purpose for horticultural identification, perhaps due to deterioration or to the fact that the nomenclatural Type need not be typical of the taxon. Example: The Standard Specimen for Dracaena fragrans 'Massangeana' was designated as Hetterscheid HDR22, (conserved at WAG) by J.J. Bos et al. in Edin. Journ. Bot., 49(3): 329 (1993) even though the Type for the epithet "massangeana" was lectotypified in the same paper as being the plate opposite, Rev. Hort. Belge., 8:169 (1882). Horticultural Herbaria Standard Specimens are maintained at a public herbarium with a tradition for maintaining herbarium cultivated plant material.   Herbarium Material Herbarium material must be maintained by conventional methods. A dried Standard Specimen should be recognised by keeping it in a specially marked folder. A dried Standard Specimen should be accompanied by a description outlining the distinguishing characters of the cultivar. Where appropriate, this description should also include details of parentage, the origins of the cultivar and should cite the valid publication of the epithet. If this description has been published, the citation should be given. Duplicate Standard Specimens should be prepared at the same time for distribution to other herbaria and must be clearly marked as being Duplicate Standard Specimens. The name of the herbarium holding the Original or Substitute Standard Specimen must be clearly stated on the duplicates. Herbarium Standard Specimens should also contain a note defining the colours of important parts using an internationally accepted colour chart (such as that jointly published by the Royal Horticultural Society and the Flower Council of Holland). The name of the colour should always be stated next to its colour code. The exact whereabouts of any original living material of the specimen should be added to the herbarium specimen but this information must be dated as precisely as possible since some kinds of plants are frequently moved to different planting positions.   Selecting Substitute Standard Specimens A Substitute Standard Specimen for a clone is fixed upon valid publication or re-publication of the epithet, together with a full description in a modern language of the clone and the citation of the specimen number and herbarium holding the Substitute Standard Specimen. The description should include a diagnosis defining its differences from similar cultivars. A copy of this published designation should be kept with the Substitute and any Duplicate Standard Specimen. Before selecting a Substitute Standard Specimen for a clone, the originator of the plant and the author of the epithet must be consulted to confirm the name of the specimen or illustration. The dated signature of such parties on a determination slip greatly enhances the credibility of the designation. If the originator of the cultivar or the author of its epithet is no longer available or willing to examine a specimen, the advice of other experts should be sought in establishing the correct epithet for a specimen. If possible, a taxonomist, expert in the group of plants involved, should be asked to make a determination on the specimen. Piers Trehane

HORTAX NEWS Vol 1, Part 1 - 10 December 1993

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