Aaron, The genus Dianthus is a large one, containing about 300 species. Dianthus Caryophyllus is the carnation and there are several hundred cultivated varieties of that species alone. That is the carnation we often use in fresh flower arrangements. Other Dianthus we see in the garden as perennials, and even annuals (pinks are in the Dianthus family and are an annual in most areas of the U.S.). Petal number and orientation are two ways botanists would distinguish one Dianthus species from another.   - Bridget