Hello Gardeners, I’m Amanda McNulty with Clemson Extension and Making It Grow . This is a mini-botany lesson and it is might be helpful as gardening catalogues are filling up our mailboxes. Although Linnaeus developed the binomial system of classification that identifies an organism by just two names, the genus and species, you’ll find a third name for many plants being sold. Usually the third name is a cultivar which means it was selected or developed by growers and usually has to be