Plant taxonomy is a system of classification used by botanists and horticulturists. We use the model developed by Linnaeus (1707-1778). Improving on the models of his predecessors, Linnaeus simplified the naming procedure through the "binomial" system.
Linnaeus' binomial system uses one Latin name to indicate the genus, and another to indicate the specific epithet. Together, the genus and epithet comprise the "species." E.g., plant taxonomy classifies bittersweet nightshade as Solanum dulcamara, where the first Latin name is for the genus (nightshade), and the second is for the specific epithet (bittersweet). "Binomial" means, literally, "characterized by having two names."
- The species is a subset of the genus.
- The genus begins with a capital; the epithet with lower-case. Both are italicized.
- When we translate from Latin, we reverse the order of the names, putting the epithet before the genus.
- Sometimes in plant taxonomy, you'll see a third name. In such cases, we're simply getting more specific, accounting for variation within a species. Most commonly, this third name is a cultivar, and it will appear in single quotation marks.
- Sometimes yet another word is added after the genus name and epithet, which is neither italicized nor set off by quotation marks -- the name of the person who first described the plant. These names are sometimes abbreviated. When the name is abbreviated as "L," it stands for "Linnaeus."
- When you see a genus name, followed by the letter "x," followed by an epithet, this is an indication that the plant is a cross between two different plant species -- a "hybrid plant."
Why do we use this binomial system? Why aren't the common names of plants "good enough"? We use scientific plant names (or "botanical plant names") to avoid confusion, since they are an international language of sorts. That doesn't mean that they, themselves are never confusing; botanists sometimes decide the a plant taxonomy is "wrong" and change the name. But by and large, the use of the binomial system achieves greater clarity than the use of common plant names.
To look up a particular plant on my website by botanical name, please consult my list of scientific names of plants.