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 Agriculture and Food, 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).