Download Appendix A. Scientific Names Hybrid

Appendix A. Scientific Names
Different people in different countries may call the same tree by different "common names."
For example, what Americans refer to as Douglas fir has over 20 common names. In Chile, it is
called "Pino Oregón."
Almost 300 years ago, Carl Linnaeus devised a system of nomenclature to avoid this confusion.
This system extends to plants.
The first part of the scientific name, usually a Latin name given in italics, refers to the genus. For
example, in trees, the genus name of Douglas Fir is "Pseudotsuga" (translated into "False
hemlock,” one of the common names of Douglas fir). It helps botanists around the world
understand what tree they are discussing.
To further classify the plant, a species name is used; it is also in italics. In many cases, it tells
something about the plant. For example, "Acer macrophyllum" refers to a maple (Acer) with
large leaves (macro equals large, and phyllum equals leaf).
Possibly the most fun scientific name is Ilex vomitorium, which translates loosely into "Holly
which should not be eaten."
Sometimes genus and species are not sufficient to classify plants, so there are some other
terms:
Hybrid
A hybrid is an offspring of two other plants. A good example of this on campus is:
London Planetree (scientific name Platanus x acerifolia), the offspring of American Sycamore
(scientific name Platanus occidentalis) and Oriental Planetree (scientific name Platanus
orientalis).
In this case, hybridization apparently occurred accidentally with parent trees near around 1683
in England.
However, hybridization today is a multibillion-dollar business, as plant breeders attempt to
improve attributes of their plants. For example, Quercus x warei is a hybrid of parents Columnar
English Oak (scientific name Quercus robur 'Fastigiata') and Swamp White Oak (scientific name
Quercus bicolor); the offspring has better tolerance to cold and disease.
The standard notation for hybrids is an "x" between the genus and species names.
Cultivar
A cultivar is a cultivated variant of a species.
Cultivars may either occur because of cross-pollination or by natural variation in plant
characteristics.
Cross-pollination may be accidental (e.g. bees pollinating different plants in proximity) or
deliberate (e.g. by people hand-pollinating two different plants).
Cultivars may also happen if buds or cuttings are grafted from one kind of plant to another.
Cultivars may not reproduce true from seed (e.g. seeds from a Weeping Cherry, if planted, may
not produce another Weeping Cherry).
Cultivars may arise in the wild, but may be the results of natural variation. The cultivar is
marketed for a certain trait, e.g. flower color (Spring Snow Crabapple, scientific name Malus
'Soring Snow'); tree size or shape (Weeping Norway Spruce, scientific name Picea abies
'Pendula'); disease resistance (several cultivars of Dutch Elm, scientific name Ulmus x
hollandica), which are resistant to the Dutch Elm killer Dutch Elm Disease.
There must be an upside for plant breeders doing this work: Cultivars are given "plant patents",
which are like other patents: the plant breeder has rights to the cultivar, and either someone
else is forbidden to propagate for sale the cultivar, or the plant breeder gets a royalty. For
example, U. S. Plant Patent PP12,673 for 'Long,' a cultivar of the hybrid Quercus x warei.
Plant patent lives vary, but 25 to 30 years is the common length.
The standard notation for cultivars is single quotes, and the cultivar name is non-italicized.
Variety
A variety is a different-looking form of the same species which occurs in nature. Seeds of the
variety will be true to the parent. There are two good examples on campus:
Thornless Honeylocust (scientific name Gleditsia triacanthos var. inermis), a thornless variety
of Honeylocust (scientific name Gleditsia triacanthos) which sometimes occurs in nature.
Weeping Nootka Cedar (scientific name Chamaecyparis nootkaensis var. pendula), a weeping
variety of Nootka Cedar (scientific name Chamaecyparis nootkensis) which also may occur in
nature. Some people (me included) lump these in with cultivars.
The standard notation for a variety is the non-italicized "var."
The line between these three terms is blurred.