Unseasonably mild weather has caused an early profusion of blossoms on many fruit trees, including the popular flowering plums.
Photograph by Shari Kaplan
The true roots of a plant's identity found in its name
By Tony Tomeo
II have always thought it practical to describe featured plants' species by their botanical or Latin names. Common names may be confusing because so many of them are regionally specific. For example, the coast live oak is a completely different species from the Japanese live oak, the Virginia live oak, or the Texas live oak; all of which are known as live oaks.
However, botanical names are the same everywhere. The rules for naming species are known as nomenclature. Although I never understood quite why, botanical names are always italicized, or underlined, if written to signify that they are Latin words.
All plants are divided into increasingly specific groups, starting with the broadest and, eventually, ending with the most exclusive. Nomenclature is only concerned with the last two of these classifications: genus and species. It is also often helpful to know the "family," or third classification. Cultivars and varieties are variations within a species. Because cultivars and varieties are not Latin, they are not italicized.
I sometimes find it useful to explain nomenclature as it relates to cars. Two examples may be a silver maple, Acer saccharinum, and a Park Avenue by Buick. The silver maple belongs to the family Aceraceae, just as the Park Avenue belongs to the family of General Motors. The families are divided into genera (plural for genus), such as Acer and Buick. Species are specific classifications within the genera, such as saccharinum and Park Avenue. The silver maple is available as the cultivar "Wieri," just as the Park Avenue is available as the "Ultra." This can all be translated into Acer saccharinum "Wieri" and Buick, Park Avenue "Ultra."
Species are defined as plants that can produce seed among themselves. Some species may appear to be the same, but are divided by genetic incompatibility. Likewise, many varieties and cultivars within a species are very different from each other. Hybrids may occur between species or genera. Placement of an "X" within a botanical name indicates how the cross occurred. For example, Platanus X acerifolia is a hybrid of two species and X Fatshedera lizei is a hybrid of two genera. The "X" is not pronounced and, very often, not included in spelling.
Varieties are naturally occurring, genetically transmitted variations within a species, such as the "Heavenly Blue" variety of morning glory. Seed from this morning glory will produce plants resembling the distinct variety. Cultivars are variations of a species that can only be produced vegetatively (cloned), such as by cuttings. Cultivars are either too genetically unstable to produce similar seed, or unable to produce viable seed, as is common with hybrids. Most cultivars are mutations that produce genetically normal seed.
Tree of the Week: Flowering plum
Although it was somewhat cold recently, the previous warm weather has induced premature bloom of many flowering trees. During normal winter weather, the flowering plum, Prunus blireiana, may start blooming now or may wait as late as April. The genus of Prunus includes many other species of flowering and fruiting plums, as well as prunes, apricots, nectarines, peaches, cherries and almonds, some of which are also currently in bloom. However, Prunus blireiana continues to be one of the most popular.
The trees may get to 25 feet high and wide, but are usually smaller. The lightly fragrant, double flowers are pink and profuse. Unlike cherry flowers, they are not suspended on pedicels (floral stems), but are attached directly to the stems. Leaves emerge purplish red, but become dark greenish bronze during summer. Trees are normally fruitless, but may produce a handful of small red plums at maturity.
Flowering plums are excellent for small gardens, but should not be planted in lawns or where bedding plants require generous irrigation. Root rot is a problem in dense soil that is constantly moist. Aphids and scale may become problems, but are easily controlled. Various species and cultivars of the most popular flowering plums are available at even the most basically stocked nurseries.
Stems may be cut and brought inside while in bloom, or forced. Branches suitable for forcing exhibit swelling buds that are just beginning to show the color of the flowers through the bud scales. When brought inside where the "weather" is warmer, the bloom cycle is accelerated and flowers soon open. Stems from various other species of Prunus may also be forced.
Horticulturist Tony Tomeo may be contacted at 408.358.2574.
Saratoga, California Since 1955
