Last month I discussed the system of binomial nomenclature that is used to give scientific names to plants and animals. This month I'd like to turn to another topic. Where do the scientific names of plants come from?
The biologist who first describes a new plant (or animal) and publishes the description has the honor of naming it. If the plant does not fit in to an existing genus, the biologist can invent both a new genus and a new species name. If, however, the plant falls into a genus that has already been described, the biologist can only propose a new species name.
Genus names are usually nouns derived from either Latin or Greek (sometimes Latinized Greek or English!), and species names are generally adjectives, also derived from Latin or Greek roots. It is the Latin and Greek that turns so many people off on scientific names.
Some genus names such as Quercus (oak), Prunus (plum), and Betula (birch) are the perpetuation of names used for those plants by the ancient Romans. Other genus names refer to some outstanding characteristic of a plant. For example, the genus name Chrysanthemum (which is also the common name of this popular garden flower) comes from Greek roots meaning golden (chrysos) flower (themum). Yet other genus names, such as the genus name of the Dusty Miller, Artemisia, referring to the Greek goddess of the moon and wild animals, are pure whimsy.
As in Spanish, adjectives in Latin must "agree" with the nouns they modify; that is, they take different endings depending upon the gender and other grammatical properties of noun. This explains why two species names associated with different genus names may be spelled differently even when they mean the same thing. For example, the species names of the Wild Sweetpea, Lathyrus arizonicus, and the Arizona Rose, Rosa arizonica, both refer the state of Arizona but have different spellings because they must agree with genus names (nouns) having different grammatical properties.
The species names of many plants are derived from the names of people, often the botanists who named them. We see examples of this in many of the plants of our own region. The cottonwood, Populus fremontii, is named after John Charles Fremont (1813-1890), the famous soldier, explorer, and naturalist who was once governor of Arizona Territory. The catclaw, Acacia greggii, is named for Josiah Gregg (1806-1850), a frontier trader and author who traveled widely in northern Mexico and the Southwest. There are numerous other examples.
Species names for most plants describe some aspect of the form or habitat of the plant. For example, one of the eucalyptus trees that flourishes in this area is Eucalyptus microtheca. The species name, microtheca, comes from the Greek roots, micro and theca, meaning small seed. Similarly the species name micropyllum or microphylla, both come from Greek roots meaning small leaf. The palo verde Cercidium microphylhm, and the Texas mulberry, Morus microphylla, are both aptly described as having small leaves.
If you are interested in finding out more about the names of plants, there are many places to look. One of the easiest is your dictionary which has a lot of information about the origin of the scientific names of plants and animals. Many books on general and regional botany also contain a wealth of information about plant names. And finally, if you are really hooked on the subject, there are several books that specialize in the topic. One of the most popular is a book from Dover Publications by Liberty Hyde Bailey called, How Plants Get Their Names.