The Vitis genus has traditionally been divided into two distinct sections called Vitis (previously Euvitis) and muscadinia and this has been confirmed by DNA classification. The two sections may be differentiated not only on the basis of appearance but also by chromosome number. Muscadinia has 40 chromosomes while Vitis has only 38. (This is a frustration to vine breeders, who would welcome ready access to the many pest and disease resistant genes of Muscadinia.)
Most Vitis species are native to North America (see american vine species) and Asia. The common wine grape species Vitis vinifera is native to Europe and the Near East and is commonly divided into two subspecies, the wild Vitis vinifera subsp. silvestris and the cultivated Vitis vinifera subsp. sativa. The latter shows great diversity as a result of selection and cultivation by man, and three basic eco-geographic groups of varieties, or proles, were created by Russian ampelographer Negrul in 1938 (occidentalis, pontica, and orientalis), reflecting differences between origin and end use. Each prole contains numerous grape varieties (or cultivars), for example ‘Cabernet Sauvignon’, which are themselves subdivided into numerous clones. (Botanists put the names of varieties in inverted commas.) See vitis and vinifera for more details. The full botanical classification of Cabernet Sauvignon might therefore be: order Vitales, family Vitaceae, genus Vitis, section Vitis, species vinifera, proles occidentalis, variety ‘Cabernet Sauvignon’, clone INRA BX 5197.