Most cultivated Vitis varieties are wind-pollinated with hermaphroditic flowers containing both male and female reproductive structures, while wild species are dioecious.

[6] In the wild, all species of Vitis are normally dioecious, but under domestication, variants with perfect flowers appear to have been selected.

Flower buds are formed late in the growing season and overwinter for blooming in spring of the next year.

Vitis is distinguished from other genera of Vitaceae by having petals which remain joined at the tip and detach from the base to fall together as a calyptra or 'cap'.

The fruit is a berry, ovoid in shape and juicy, with a two-celled ovary each containing two ovules, thus normally producing four seeds per flower (or fewer by way of aborted embryos).

Grape species occur in widely different geographical areas and show a great diversity of form.

[12] Many species are sufficiently closely related to allow easy interbreeding and the resultant interspecific hybrids are invariably fertile and vigorous.

Thus the concept of a species is less well defined and more likely represents the identification of different ecotypes of Vitis that have evolved in distinct geographical and environmental circumstances.

[13] Approximately 25 species are known in North America, and these were studied extensively in the late 1800s by German-American botanist George Englemann.

[20][a] Phylloxera is an American root aphid that devastated V. vinifera vineyards in Europe when accidentally introduced in the late 19th century.

[14] Attempts were made to breed in resistance from American species, but many winemakers and customers did not like the unusual flavour profile of the hybrid vines.

In Greek mythology, Dionysus (called Bacchus by the Romans) was god of the vintage and, therefore, a grapevine with bunches of the fruit are among his attributes.

The grapevine is featured on Hasmonean and Bar Kokhba revolt coinage, and as a decoration in mosaic floors of ancient synagogues.

In that sense, a vine is placed as sole symbol on the tomb of Constantia, the sister of Constantine the Great, and elsewhere.

In Byzantine art, the vine and grapes figure in early mosaics, and on the throne of Maximianus of Ravenna it is used as a decoration.