Sour orange


Sour orange, or bitter orange, is native to Cambodia, Laos, Myanmar, Thailand, and Vietnam. It reaches a height of 30 feet, with a trunk 10 inches in diameter. Young branches have long, slender spines. The leaves are up to 5.5 inches long, generally with finely serrated borders and the sides of the petiole covered by a small blade. Flowers are up to 1.5 inches wide, have five petals, and are solitary or form small groups. Fruits are up to 3.5 inches wide and are frequently wider than long, with a rough, thick peel. It flowers in spring and the fruits mature mainly during fall and winter. The fruit is too bitter to be consumed fresh, although a sweet variety is cultivated locally. The peel and the pulp are the main ingredients of orange marmalade and paste. The peel, leaves and flowers produce oil for soaps, liquors and perfumes. The generic name derives from the common name for Citrus medica (citron). The species name means orange, in reference to the color of the exterior and interior of the fruit.

The photographed tree is west of the chancellor’s house and is the only member of the species in the campus. It is a remnant of a citrus collection that existed in the area.

Flowers: this link.

Citrus aurantium (Rutaceae)