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The Language of Horticulture


by Denise Adams
Department of Horticulture and Crop Science
The Ohio State University



One area of horticulture which continually seems to intimidate many students of the discipline is the language of horticulture, binomial nomenclature. Ultimately whether or not you can locate the specific plant that you want depends on your understanding and adherence to a few simple rules. If you decide that you want a bluebell for your garden and convey this to your nurseryman, what would you expect in return? Bluebell is a common name for several different plants in the following genera:

Scilla Campanula

Mertensia Polemonium

Obviously more specific information is needed and this is where binomial nomenclature, also called the botanical or scientific name, comes in.

The typical horticultural name that is given to a plant has three parts: the two-name binomial with author designation, plus a cultivar name: Acer rubrum L. 'Autumn Flame'

Acer
genus. The genus name designates a group of closely related plant shich have enough in common to be distinguished from other such groups. A genus may include one or more species.
rubrum
specific epithet. The specific epithet is often a descriptive word: alba (white), brevis (short), sativa (cultivated), etc.
Acer rubrum (Genus + specific epithet)
species. The genus and specific epithet compose the species name which is underlined or italicized. By definition a species is a distinct succession of interbreeding individuals from gneration to generation. When two different species cross, the result is an interspecific hybrid designated: Dianthus x allwoodii (Dianthus caryophyllus + Dianthus plumarius). Less common is the intergeneric cross, for example, X Heucherella tirelloides (Heuchera sanguinea x Tiarella cordifolia).
L.
stands for Linnaeus who first named this tree. The author designation is either a single letter or an abbreviation which indicates the originator of the name. It is often omitted in horticultural trade literature such as catalogs.
'Autumn Flame'
cultivar. The term cultivar was coined by Liberty Hyde Bailey in the first part of the century from 'cultivated variety.' This term is defined as 'an assemblage of cultivated plants which is clearly distinguishable by any characters (morphological, physiological, cytological, chemical, or other) and which, when reproduced sexually or asexually retains its distinguishing characters.' (International Code of Nomenclature for Cultivated Plants, 1980).

 

A cultivar may be propagated sexually or asexually. Cultivars may be produced from seed and therefore may exhibit some variation in traits other than that for which the selection was made. For example, Lavandula angustifolia 'Munstead Dwarf' is a lavender selected for its dwarf habit. Even if seed grown, all plants so named should not exceed 18 inches in height, but may show slight variation in flower or foliage color, habit, etc. In order for all Munstead cultivars to be identical, or clones, they would have to be propagated asexually from cuttings. Many people do not realize that 'cultivar' is not synonymous with 'clone.'

Pronunciation is sometimes an obstacle to feeling comfortable with botanical names. Remember that the names are not Latin, but rather 'latinized.' Most people pronounce latinized words as they speak their own language: just by sounding out the syllables.

When perusing catalogs another feature of naming plants becomes apparent. That is the use of the trademark (designated ® or TM). A trademark is legally defined as a word(s) or symbol which identifies the place of origin of a product. Conard-Pyle's Star ® trademark is a good example. The consumer recognizes that roses with the Star® designation are from Conard-Pyle and can make an assumption of quality with this information.

Confusion arises when a company uses a trademark name as a cultivar name. For example, a particular holly is often designated in the trade as Ilex x 'China Girl' (shown at left). Many of you will recognize this name. If, however, you were to come upon Ilex x 'Mesog', would you expect to know this holly? Probably not. In fact, the cultivar name for this holly is 'Mesog' and the trademark is China Girl®.

This naming practice violates both trademark specifications and nomenclatural rules, but it is becoming increasingly common. The reason is profit. If a breeder patents a new plant, he restricts other from propagating it without paying royalties. The patent is in effect for 17 years. A trademark may be renewed indefinitely. So when the patent expires, anyone may propagate the plant, but they must call it 'Mesog' which does not have any commercial recognition factor. The name China Girl® is still the property of the original producer.

Sometimes the names of plants change. For example, the Chrysanthemum genus was recently split into eight different genera, including Dendranthema, Tanacetum, and Leucanthemum. Name changes usually indicate reclassification, often as a result of advances in molecular biology. It may take gardening literature and nursery and seed catalogs years to reflect such changes and in the meantime you may note many inconsistencies in the names of plants.

Adherence to the simple rules of binomial nomenclature will produce greater consistency and reliability in the nursery, floriculture, and landscape industries. Insuring that plants are named correctly obviously benefits both the producer and the consumer.

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