Latin vs. English
The Latin name is usually written like this: Coreopsis verticillata `Moonbeam'. The name of the genus comes first and is capitalized. Then comes the name of the species, lower-cased. Finally comes the particular variety, which is usually a descriptive name in English, and is in quotes.
Unfortunately, official Latin names of plants change often enough to keep even expert botanists on their toes trying to keep up with them. But don't be afraid, there is no need to memorize a lot of plant Latin. Just try to remember the names of your favorite plants, so if you want to find out more about them or recommend them to a friend, you'll be sure which plants you're talking about.