Rod's video tree tours

Welcome to Rod's Tree Tours for the University of Nevada Reno.

These YouTube video tours take you around the trees and Arboretum areas of the University. At the beginning of each tour is a map to help orient you. The trees in these tours are identified by both common and scientific name.

Throughout the tours there are some botanical classification terms and references (e.g., Nevada State Champion) with which you may not be familiar and are defined in the appendices below.

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, including the following:

  • 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.

Appendix B: State champion trees

  • State Champion Trees

    There is a list of State Champion Trees for each state in the U.S. (as well as a National list). To be a State Champion Tree, it must be the biggest of each kind in the state. The Nevada Division of Forestry maintains information and a registry through Nevada's Big Tree Program.

    Championship status is based on a point system, established nationally. Points are awarded as follows:

    1. 1 point for each inch of circumference at 4.5 feet above ground;
    2. 1 point for each foot of height;
    3. 1/4 point for each foot of average crown spread;
    4. These three numbers are totaled, and, if the nominated tree has at least 10 points more than the next biggest tree, it is the State

    There are two types of State Champions generally recognized:

    • Champions are the biggest of their kind in the state
    • Co-champions are tied for the biggest of their kind in the state, within 10 points

    Almost all tree species in Nevada are introduced; having had less time to grow to a large size, they naturally are not as big as trees native to an area and perhaps several hundred years old. For example, the National Champion American hornbeam growing in New Jersey (where it is a native species) has 235 points, and the largest American hornbeam in the state has 47 points. But, this tree was probably planted in the last 20 years.

    To acknowledge the efforts of Nevadans to increase species diversity, the Nevada Division of Forestry (who administers the state list) has created a new category, "Up-and-coming Trees."