Names are essential for communication. This is just as true for plant life as it is for animals. Most of the commonly used woody plants have been given so-called common names, in some cases, unfortunately, more than one. The duplication of different common names for the same plant is a particularly serious problem as one moves from one section of our country to another. For example, consider the confusion when the common name "cedar" is applied to plants that include arborvitae, cedar, cypress, false cypress, juniper and sequoia. We are not excluded from this problem in our upper Midwest and Northern Plains. To cite just a few examples, the American Linden is called Basswood, the American Hop-hornbeam is referred to as Ironwood and Amelanchier alnifolia is listed under such names as Juneberry, Serviceberry, Shadblow and Saskatoon.
Duplication of names is not only an individual plant problem, but the magnitude of the problem increases when entirely different plants are dubbed with the same name. For example, laymen commonly refer to Balsam Poplar, Balsam Fir and a hybridized poplar as Balm-of-Gilead. To a traveler in a foreign country, local common names are even more troublesome. Common names, however, can be quite satisfactory to the non-technical person, if an attempt is made to standardize them. Such an attempt was made by the American Joint Committee on Horticultural Nomenclature when a dictionary of plant names, entitled "Standardized Plant Names," was published in 1942. This reference, however, is now outdated and is in need of revision.
Definitive rules for writing the common names of plants do not exist. The first letter of each part of the common name is capitalized in this publication. An exception is when the common name is misleading and suggests that a tree or shrub is falsely related to a distinct group of woody plants. In such cases, this part of the name is sometimes separated by a hyphen and the latter part is not capitalized:
e.g. Russian-olive Russian-olive is not related to the olive family or European Mountain-ash European Mountain-ash is not a true ash
Although common names are important, considerable confusion exists due to duplication of names. Actually, one cannot be certain the exact plant desired is purchased if only the common name is used. This is particularly a problem if one purchases plants through the mail.
To avoid confusion associated with common names, botanical or scientific names have been given to plants, one to each kind and shared by no other plant. A scientific name for a plant is universal; that is, the same throughout the world. This system of naming is credited to the Swedish botanist, Linnaeus, 1707-1778. The scientific name is a binomial, that is, made up of two words and both are latinized. The first is the generic name, which is always capitalized. The second is the specific name which is not capitalized. Both words are either italicized or underlined:
e.g. Acer ginnala (genus) (species)
The above is the scientific name of the Amur Maple.
In nature, not all plants of a species are necessarily alike. Plants in nature that differ from the typical element of the species (and form a geographically significant population) are given a botanical variety name. A botanical or natural variety is designated by var.; it is latinized, and either italicized or underlined. Like the species name it is not capitalized:
e.g. Picea glauca var. densata (genus)(species) (natural or botanical variety)Black Hills Spruce
The Black Hills Spruce, native in western South Dakota, is generally accepted to be somewhat denser, more compact, slower growing and more drought-tolerant than the typical species White Spruce (Picea glauca) native from coast to coast across northern North America.
The term cultivar was introduced in 1961 by the International Commission for the Nomenclature of Cultivated Plants to designate a "cultivated variety." A cultivar is significant for the purposes of agriculture, forestry, or horticulture and retains its distinguishing features when reproduced. A cultivar is developed or selected, propagated and maintained under cultivation by man. New plants (cultivars) are derived by various means, e.g. hybridization (hybrids), naturally occurring or man-induced genetic changes which give rise to sports and mutants and by man-made selections from nature. A cultivar name is written in the common language of the country where it was named:
e.g. Fraxinus pennsylvanica `Kindred' (genus) (species) (cultivar)
The above is the scientific name for Kindred Green Ash.
A clone is actually a type of cultivar. Clones are plants which are propagated vegetatively (i.e. asexually by such means as cuttings, grafting, budding, tissue culture or layering) from a single selected parent. Therefore, each plant is identical. Many horticultural landscape plants, including such Green Ash cultivars as `Kindred', are propagated clonally to retain their desirable characteristics.
Another type of cultivar is a seed strain. Seed strain cultivars are propagated from seed to reduce cost of production and to retain certain characteristics, e.g. resistance to pests, improved winter hardiness or better adaptation to other environmental stresses. Some trees and shrubs available for conservation plantings, e.g. shelterbelts, farmstead windbreaks and wildlife plantings, are cultivar seed strains:
e.g. Pyrus ussuriensis `McDermand' (genus) (species) (cultivar seed strain)McDermand Pear
Other examples include Sakakawea Buffaloberry and Midwest Crabapple. It is important that the parental plants be isolated from unwanted pollination or much of the advantage of a cultivar seed strain may be lost.
A hybrid cultivar is produced by crossing two or more species or cultivars. Most hybrid woody plants are vegetatively propagated because they fail to come true from seed. Hybrid cultivars require long, cumbersome names if the complete parentage is recited in the scientific name. Also, in some cases, only the female parent is known, therefore, hybrids are sometimes named by listing the genus and the cultivar name only. The cultivar name should be preceded by an x which designates that it is a hybrid:
e.g. Malus x `Spring Snow' (genus) (hybrid cultivar)Spring Snow Crabapple
If a hybrid species epithet has been assigned, it is most technically correct to include the species:
e.g. Malus x adstringens `Radiant'Radiant Crabapple
Most scientific or botanical names come from Latin roots and describe specific characteristics of the plant. Table 1-1 shows several Latin words used in plant names. Latin names, for example, may describe colors, textures, growth habits, or shapes of plants or plant parts.
Color Growth Habit rubra - red scandens - climbing alba - white repens - creeping nigra - black fastigiata - narrow, erect glauca - bluish globosa - globe aureum - yellow nana - dwarf purpurea - purple gigantea - giant
Texture rugose - rough glabrous - smooth tomentose - hairy, felt-like pungens - sharp, piercing
Shape deltoides - triangular stellate - star-like dentatum - coarsely toothed cordate - heart shape
e.g. Latin Populus deltoides English Poplar, triangular shaped leaves Cottonwood
Latin Picea pungens var. glauca English Spruce, sharp needles, bluish cast Colorado Blue Spruce
Figure 1-1 shows a part of the woody Plant Kingdom divided taxonomically into eight levels from division to cultivar. The Gymnosperms (Div. Coniferophyta) comprise the conifers, so named because their seeds are borne in a cone. Angiosperms (Div. Anthophyta) produce seed enclosed in a fruit. Five tree orders are included.
Figure 1-1. A partial list of the woody plant family tree.
Three deciduous and three conifer families are represented in Figure 1-1. Deciduous trees that drop their leaves in the fall are represented by Ulmaceae (the Elm family, including Hackberry); Aceraceae (the Maple family); and Oleaceae (the Olive family, including Ash and Lilac). The conifers are represented by Pinaceae (the Pine family, including Pine, Spruce and Fir); Cupressaceae (the Cypress family, including Arborvitae and Junipers); and Taxaceae (the Yew family).
Further delineation of several species of the Ulmus (Elm) and Picea (Spruce) genera illustrate the separation of natural (or botanical) varieties and cultivars (cultivated varieties).
Two conifer and 18 deciduous tree families are included in this publication. Eighty-five species or taxa are discussed.
Although the number of names to learn may seem overwhelming, it is very important that nurserymen, foresters, natural resource managers and conservationists know the correct scientific and common names of plants in order to communicate properly. Knowledge of scientific names is essential for effective use of reference books to check origin, hardiness, height, growth habit, cultural requirements and propagation of woody plants. If the meaning of Latin names is understood, scientific names are also helpful in describing the plant in question. Knowledge of hardy and nonadapted plants will allow the user to make valid recommendations and further serve to protect the consumer.
In conclusion, such words as genus, species, cultivar, clone and hybrid should be commonly used and understood by anyone working with woody plants.
The number behind each statement pertains to the references listed below.
Control Wind Erosion - When properly spaced, field windbreaks can reduce soil losses from greater than 30 tons/acre/year to less than 1 ton/acre/year. 1
Increase Crop Yields - Research studies by Baldwin '88, Kort '88, and others have shown that crop yields can be increased by 5-35% when protected by a system of field windbreaks. 2,3
Increase Water Use Efficiency - Properly designed field windbreaks can trap and spread snow across adjacent fields, increasing moisture supply and yield potential. Increased yields result, in part, because of reduced transpiration during the growing season. 4
Reduce Home Energy Costs - Studies by DeWalle and Heisler '88 show a home heating cost reduction of 15-25% for homes situated in the north central states when protected by a properly designed windbreak. 5
Provide Urban Cooling - University of Minnesota studies indicate that direct shading of southern and western exposures of suburban homes can result in a 25% reduction in peak cooling energy demands. 6
Provide Noise Control - Cook and Van Haverbeke 1978, reported that a tree and shrub buffer strip resulted in a relative noise reduction of 5-10 decibels. 7
Improve Snow Control - Colorado studies by Tabler and Associates show that over a fifty year period, living snow fences are 62 times cheaper/unit of snow trapped than is slat fence. 8
Protect Livestock - Iowa State University studies show fewer incidences of death, decline, frozen udders and scrotums in animals protected by windbreaks. 9
Improve Weight Gain - Kansas State University studies show 10-15% less feed is required for cows protected from winter winds. Certain species of livestock show greater weight gain when shaded from hot summer sun. 9
Improve Milk Production - Studies by Johnson '65 showed winter wind protection can reduce milk production losses by 48%. 9
Protect Wildlife - Protection from winter winds can mean the difference between life or death. Johnson and Beck '88 (Nebraska) found 108 species of birds and 28 species of mammals utilize windbreaks. Nearly half benefit substantially or moderately from the presence of shelterbelts. 10
Improve Ground Water Quality - A 1988 University of Iowa study showed that a buffer strip of poplar trees could reduce near surface ground water nitrogen concentrations by 95%. A Georgia research project by Lowrance et al. 1984, credited forest buffers with removing 80-90% of the nitrates, 50% of the phosphates and 99% of the sediments from runoff water from adjacent agricultural fields. 11,12
Provide Better Storm Water Runoff Control - USDA studies in the Salt Lake area showed a 17% reduction in runoff from watersheds protected by native woody vegetation. 13
Improve Income Alternatives - Christmas tree production, nut production, fruit and preserve enterprises all provide income that could amount to $850 or more per acre per year.