Upon completion of this chapter, you should be able to

• explain the reason for knowing both scientific and common names of plants.

• describe many of the ways horticulturists classify or categorize plants.

• explain and use plant hardiness zones and a hardiness zone map.

• explain and use a heat zone map.

• identify plants based on their physical features.

• use a plant key.


woody plant


hypogynous flower



perigynous flower



epigynous flower


bedding plant

terminal bud


native plant

petiole scars


exotic plant

lenticel scars


naturalized plant

stipule scars


aquatic plant



specimen plant


accent plant


The previous chapter explained how plants are classified and how that classification leads ultimately to the assignment of specific scientific names to each plant. Each plant’s scientific name is derived from the genus and species in which it is classified. Since there are two parts to each scientific name, it is termed a binomial. The scientific names are
derived predominantly from the classical Latin and to a lesser extent the Greek languages. The use of the Latin language, which is no longer spoken ensures that the language will not change and thereby affect the scientific terminology.

PLANTSПодпись: FIGURE 2-1. Karl von Linne (Linnaeus), the father of taxonomy, was the first to establish a binomial system of nomenclature for classifying plants and animals. (Courtesy of Council of Linnean Society of London)A plant’s scientific name gives it international recognition, since a specific scientific name can only be assigned to one plant, unique in some way from all others in the world. However, plants also have common names by which they are known within a particular country or region. While inconsistent and often misleading, common names have widespread acceptance among people outside the horticulture professions, so a green industry practitioner must know most plants by both the scientific and common names. Laymen will normally use the common name in conversation with the horticulturist, while pro­fessionals will use the scientific names in business matters to ensure understanding.

In discussing plant nomenclature, it is appropriate to acknowledge the man who first established the binomial system of classifying plants and animals. Karl von Linne of Sweden described over thirteen hun­dred different plants from all corners of the globe during his lifetime in the eighteenth century. More often referred to as Linnaeus, after the Latinized form of his name, his pioneering service truly earned him the title of father of taxonomy (Figure 2-1).