Have you ever wondered why many plants have two names - a common name and a Latin name? In general conversation most people use the common names, but plant specialists and reference books usually use the Latin ones. Why is that? Let's see.

Common names are usually descriptive and have evolved out of popular usage. Whenever a plant has some characteristic that causes it to be of interest, people have given it a name. Because there are no rules for this naming process, the same plant often acquires two or even more common names and different plants have sometimes acquired the same name. For example, people in one area may call a local plant a Yellow Slipper because it has attractive yellow flowers that look to them like slippers. People in another area may refer to the same plant as the Yellow Bonnet because to them the flowers look like bonnets. Conversely, two completely different plants that grow in different areas may be called Yellow Slippers because their flowers are similar. Another problem with common names is that only plants that have attracted wide spread interest have them. Wall flowers may never get a common name. As a matter of fact, tens of thousands of plants that have Latin names do not have a common name.

Every plant that has been described by botanists has a Latin name, and rigid rules created by international congresses of scientists surround the naming process. For example, every proposed new Latin name is closely scrutinized by biologists throughout the world to make sure it is unique. In addition, there are other rules.

You may have noticed that Latin names always come in pairs. The first name in the pair is called the genus, and the second is called the species. This is why the Latin naming system is called the binomial (bi = two + nominal = name) system. The binomial system was invented by a Swedish botanist and physician, Carolus Linnaeus (1707-1778), who used it to name and classify thousands of plants. Linnaeus not only wanted to provide a moniker by which all plants (and other living things) could be uniquely tagged but to provide a classification system as well. The binomial system for naming living things is similar to the way we name people. Everyone has a first name and a last name. The last name tells you what family the person belongs to and the first name specifically identifies an individual within the family. The genus and species names operate in a similar manner except that the genus name which is like a family name is written first instead of last. For example, the group of trees we call oaks belong to a genus called Quercus. Different kinds of oaks are given specific names that uniquely identify them. Here in Cochise County there are the Arizona white oak, Quercus arizonica, the Mexican blue oak, Q. oblongifolica; and the netleaf oak, Q. reticulata. You might consider these as cousins who all belong to the same family. The binomial Latin names are actually part of a larger system of taxonomy that attempts to classify all plants into a very large family tree, showing the genetic relationships between them all, but that's a story for another day. Before we end this discussion, we need to answer one last question about the binomial system - why Latin?

In Carolus Linnaois' day, Latin was the universal language of educated people. Since scientists came from different countries and spoke different native languages, they needed a common language to communicate and Latin filled the bill. In addition, because it was a dead language, Latin had no nationalistic overtones. Although we don't use Latin as a general vehicle for scientific communications today, we still use Latin (and Greek) as the basis for creating scientific names for living things. Imagine if Linnaeus had decided to use his native Swedish instead of Latin as the basis for plant names. We would all be struggling with Swedish instead of Latin plant names!