Wikipedia Article About Orange blossoms on Wikipedia Orange—specifically, sweet orange—refers to the citrus tree Citrus sinensis and its fruit. The orange is a hybrid of ancient cultivated origin, possibly between pomelo (Citrus maxima) and tangerine (Citrus reticulata). It is a small tree, growing to about 10 m tall, with thorny shoots and evergreen leaves 4-10 cm long. The word "orange" comes from Sanskrit "narang". Oranges originated in southeast Asia, in either India, Vietnam or southern China. The fruit of Citrus sinensis is called sweet orange to distinguish it from Citrus aurantium, the bitter orange.