All commercial orange types grown in Australia are classified as sweet oranges. These are thought to have originated from south-west China and north-east India, as did the other main types of citrus.
Sweet oranges are divided into four groups:
- Navel oranges – many types but the most widely grown is the Washington navel
- Common oranges – includes Valencia, Hamlin and Salustiana
- Pigmented oranges – blood oranges (sanguina or sanguigna oranges)
- Acidless or sugar oranges – low acid and usually fairly tasteless; not commercially important in Australia.
The Department of Primary Industries and Regional Development, with industry cooperation, has been evaluating new orange varieties since 1994. Many varieties listed here are publicly available, although a number are protected by Plant Breeder's Rights (PBR).