Understanding Scientific Names

All plants have a scientific name --- the only dependable name for a plant. Most plants also have one or more common names. Gardeners prefer to use common names instead of scientific names ---- which they often perceive as too difficult to learn.

However, the use of only common names may be confusing. A plant may have a common name that vary from one region to another. For example, Kalmia latifolia is called mountain laurel, mountain ivy, Virginia ivy, mountain kalmia, or kalmia laurel. Or, we can have one name applied to several plants. For example, tea or the tea plant could be Camellia sinensis, Chenopodium ambrosioides, Ilex glabra, Monarda didyma or others.

The scientific name is in Latin, which is the international language of science. Some people have difficulty with Latin names. Two small inexpensive dictionaries (Coombes, 1994; Johnson and Smith, 1972), give the pronunciation and a short definition for many Latin terms.

Binomial nomenclature is the system of giving each plant a scientific name consisting of two parts. The first is the generic name that desiginates the genus --- a group of related species. The generic name is capitalized, underlined, or written in italics.

Genera are grouped into families, families into orders, and on up the hierarchial levels of classification. Each level of this clasification includes plants with many characterstics in common. So plant classification is in a very meaningful and useful system.

The second part of the scientific name is the specific epithet, an adjective describing members of a genus. The species is the basic unit of classification for a group of individual plants in a population having common characteristics, yet distinct from others of another species. The epithet is written in lower case letters, underlined, or italicized. The name of a species is a binomial ---- the generic name and species epithet. The species of red maple for example is Acer rubrum, not just rubrum.

The following is an example from the Chart of Latin/Common Names:

Cornus dogwood

Cornus florida flowering dogwood

Epithets are derived from: a description of the flower or leaf, the area where the plant was discovered, in honor of a person, or its habitat. Examples include:

grandiflora large flower parvifolia small leaves

americana America japonica Japan

wilsoniana Wilson sylvatica of the forest

autumnale Autumn praecox very early

Two additional terms are variety and cultivar. They are often used incorrectly as interchangeable terms, but they have very different meanings.

A variety is a group of plants in a natural population that has distinctive features often selected by environmental pressures through sexual reproduction. A variety is propagated sexually and comes true from seeds. The varietial name is also an epithet, added after the name of the species and is preceded by the abbreviation "var." For example, Buxus microphylla var. japonica is the name for the variety of Japanese boxwood.

A cultivar is a plant selected by man for one or more unique traits and usually is propagated vegetatively in order to maintain those traits. If a new type of tomato was developed by cross pollination in a breeding program, it would be a cultivar. A cultivar name follows the species name and is enclosed within single quotation marks, not underlined or italicized, and each word begins with a capital letters.

Cornus florida 'White Cloud' White Cloud flowering dogwood

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