Because common names of plants have not been standardized, the same plant may have one name in one locale and another name somewhere else.
Take for instance the common names of Beggar Tick, Sticktight and Devil’s Pitchfork, all of which refer to the same plant, Bidens frondosa. The scientific name, however, is unique worldwide for each plant and is regulated by the International Code of Botanical Nomenclature.
A Swedish naturalist, Carl Linnaeus, devised the current naming system in 1758 to end the confusion of plant names that existed for plants in various countries. He chose Latin, then spoken by educated people, as the language for plant and animal names. Because it is no longer a spoken language, Latin is considered a dead language. But it is not extinct, since it is used in science, medicine and law.
Moving down the classification ladder, which starts with the plant (Plantae) kingdom, we come to the classification that provides the most exact identity for a plant, which is the genus. Among members of this group, further separations result in a species. So the scientific name of a plant is usually written (in italics) as genus and species. If a strain is developed from a species, it appears as a third name, for instance variety (abbreviated var.). By the way, the genus is a noun and the species is an adjective which usually provides some kind of descriptive information.
Many scientific names appear intimidating, difficult to pronounce and seemingly impossible to remember. But you are probably already using scientific names without realizing it.
Iris, Hydrangea, Forsythia, Begonia, Phlox, Aster, Magnolia and Hosta are just a few names that are actually the Latin genera of these plants. Amateur plant sleuths and native plant enthusiasts will often refer to the scientific name to be sure of the identity of a plant. You will find scientific names in seed catalogs, wildflower and tree guides, gardening magazines, and nursery plant tags.
Looking at the genus of a plant tells you that other members of the same genus usually require the same growing conditions and may share similar susceptibility or resistance to particular diseases.
Two different species usually (but not always) will not hybridize, so no separation distance is needed if growing two different species of a vegetable and you wish to save the seeds and maintain genetically pure lines.
I found it fascinating to learn that cabbage Brassica oleracea (abbreviated B. oleracea) has been bred into so many different strains or varieties, which can be gleaned from the scientific names. So Brussels sprouts, cabbage, kohlrabi, kale, broccoli, collards and cauliflower are actually all the same species. Since varieties can cross pollinate, these strains must be kept separated if you were to grow them to save the seed.
Hardly recognizable as belonging to the same species, take a look at the following classification of cabbage varieties. Cabbage is classified as B. oleracea var. capitata (meaning forming a head), Brussels sprouts are B. oleracea var. gemmifera (meaning producing buds), kohlrabi is B. oleracea var. gomgylodes (alluding to the skinny stems that grow from the above-ground tuber), Broccoli is B. oleracea var. italica (referring to its place of origin), kale and collards carry the name B. oleracea var. acapitata (not forming a head) and cauliflower is B. oleracea var. botrytis (meaning grapes).
To add one more interesting point, the widespread wildflower/weed, Queen Ann’s Lace is Daucus carota. It is the progenitor of our modern carrots, which are classified as Daucus carota var. sativus. Keep checking scientific names for tidbits of information that can add to your knowledge of what you grow.