Bitter orange or bigarade orange (Rutaceae family) is a small evergreen tree with pure white, very fragrant flowers. The tree can reach a height of 12 meters and live for hundreds of years. It was the first orange tree to arrive in the West, in the 1st century AD, and originally grew in the mountainous regions of North-East India, Northern Burma and South-West China. The peel of the fruit is thick and bitter. Up until the 15th century, this was the only orange known in Christianity. The bitter orange is by far the most commonly found orange tree in the French Riviera, where it is used to make a local specialty - a bitter orange marmalade.

Botanist's Glossary