The Naming of Horticultural Varieties of Rhododendrons
J. Harold Clarke
As most rhododendron growers are aware, the system which has been followed in the naming of varieties has led to some confusion. This has been due to the use of horticultural variety names for two kinds of varieties, namely, (a) clones which are propagated asexually from one original selected seedling, and (b) groups which include all the seedlings of a cross between two species or a species and a hybrid. Unfortunately, in most lists there is no distinction between the two so that the uninitiated may purchase what he thinks is a clonal variety but secure a seedling and perhaps an inferior one.
In an effort to improve this situation and to accomplish certain other related objectives, President Sersanous on March 22nd appointed a Committee on Nomenclature and Registration, consisting of the following: Dr. Clement G. Bowers, Cornell University; Mr. Lester Brandt, Tacoma, Washington; Mr. P. H. Brydon, Brooks, Oregon; Mr. Rudolph Henny, Brooks, Oregon; Dr. Brian Mulligan, Director University of Washington Arboretum, Seattle, Washington; Dr. Henry T. Skinner, Curator, The Morris Arboretum, Chestnut Hill, Pennsylvania, and Dr. J. Harold Clarke, Chairman, Long Beach, Washington.
On June 17th a preliminary report, as follows, was accepted by the Board of Directors of the American Rhododendron Society. The Committee would be glad to have helpful comments on this subject:
The Problem of Nomenclature of Horticultural Rhododendrons
American gardeners, except those who are botanists and plant specialists, usually identify their plants only in terms of the kind and horticultural variety. Horticultural varieties are distinguished by common names in contrast to botanical varieties with their Latinized names. Common usage in this country recognizes two kinds. There are seed varieties of annual vegetable and flowering plants which have been selected and rouged for several generations so that they come reasonably true to type from seed, as the Marglobe tomato. On the other hand there are plants which usually do not come true from seed such as herbaceous perennials, iris for instance, and woody plants such as fruit trees and most shrubs. Such plants are propagated asexually, that is not by seed but by division, layers, cuttings, and grafting. A variety of this type, which consists essentially of parts of the original plant is called a clone, or clonal variety, as Delicious apple or Peace rose. Such asexually propagated plants of the same variety, barring the rarely occurring bud mutations are identical as to the hereditary makeup but naturally vary with environment. The various plants of a clone, unless growing under widely differing environments, can be so identified by leaf, twig, and flower characters. For instance if two neighbors each buy a plant of a certain rose variety they can tell fairly easily if the two plants are actually of the same variety.
Method of Naming Rhododendrons
Many gardeners expect their rhododendron plants to belong to clonal varieties, that is that they are actually parts of one original plant, multiplied by layers, cuttings, or grafts. Many varieties, such as 'Pink Pearl', 'Purple Splendor', 'Britannia', and others actually are clones, as are most of the older hardy varieties grown in the eastern part of the United States. However, many years ago the British breeders began to follow a practice, recognized in botanical procedure, of giving a name to include all the seedlings of a cross between two species. For instance the name Fabia is used to designate all seedlings of the cross R. dichroanthum X R. griersonianum. Yet many people, in this country at least, who buy a plant of Fabia think they are getting a clonal variety and are disappointed if the plant turns out to be an inferior seedling.
There is considerable variation within most species so one breeder may select a particular type from each of two species to use in making a cross; another breeder may select parent plants of very different types and make a cross between the same two species and the offspring might be quite different in the two lots of seedlings, yet all of these seedlings would, under this system, be known by a common or "variety" name: Such well known names as 'Azor', 'Fusilier', 'Loderi', and 'Tally Ho' actually indicate groups of seedlings and not clonal varieties. Furthermore, anyone may select a particular seedling which he thinks is worthy, give it a name, and propagate it asexually as a clone, so we have Fabia, var. 'Roman Pottery', Fabia var. 'Tangerine', etc. In many cases various selections from, such a "variety" or race have been made and propagated as clones under such appellations as Type A, Type B, etc. and if the clone has received a special award in a trial garden it may be known as F. C. C. (first class certificate) or A. M. (award of merit), or a clone may be known unofficially by the name of the man who selected it or by the name of a location.
For the rhododendron fancier of long experience, who has kept abreast of the literature, and who knows the crosses and the group names, this system may seem logical. However, there has been considerable adverse comment, from people who have been disappointed to find they have an inferior seedling when they expected to have a plant identical with one which has been described as very outstanding. Articles pointing out the need for less confusion in the use of names have appeared in the publications of this Society. (1) (2)
The Public Should be Protected
In horticultural products, as with other commodities, the buyer is entitled to know what he is buying especially if he pays a good price for what he considers to be a valuable variety. It should be possible for nurserymen to explain the system of naming in their catalogs and so mark each offering that the customer would know exactly what he is getting. Horticultural writers, when presenting variety lists or describing varieties, might be expected to make clear which are clones and which are seedling groups.
In most other fields of horticulture the breeders have selected certain plants (that are each distinctive and outstanding), given them names and then propagated each as a clone. The parentage of such clonal varieties is usually on record in some publication for the benefit of other breeders. Less worthy seedlings have usually been destroyed or occasionally sold simply as seedlings for mass plantings. A number of American breeders are now raising rhododendron seedlings and it is to be hoped that they will give due consideration to this procedure, which is so well established in American Horticulture.
A Code of Nomenclature is Needed
A number of horticultural groups have found it expedient to have committees on nomenclature. There is probably more need for study and action on this subject in the rhododendron field than in most other plant groups. Such a committee should study the problem and later propose a code of nomenclature for rhododendrons which would be simple but effective. There is probably no reason to interfere with botanical nomenclature, or even with horticultural names already established, but rather the usage of names should be clarified and standardized.
No group in this country other than the American Rhododendron Society can be expected to develop such a code. It is gratifying to know that the officers of the Society are aware of the problem and are willing to meet it. If the work is properly done it should be of benefit to nurseryman, fancier, and casual gardener.
1. Anon, Seedlings vs. Clones., Quart. Bullet. Amer. Rhod. Soc., Vol. 2, No. 2, p. 2.
2. Bowers, Clement Gray, The Naming of Horticultural Rhododendrons, The Rhod. Yearbook for 1948, Amer. Rhod. Soc. pp. 13-22.