Citrus × aurantium f. aurantium (Citrus × sinensis)

Developed in cultivation in southern China and now grown throughout tropical and subtropical regions, the sweet orange is an evergreen tree with mandarin and pummelo ancestry. Its branches may bear thorns, and the pointed, oval leaves have narrowly winged stalks. Fragrant white flowers produce rounded fruits with a thick rind and juicy, sweet flesh divided into segments. Seed numbers vary among cultivars. In hot tropical climates, ripe oranges can retain green skins because warmth slows the loss of chlorophyll in the peel. Cultivated varieties are generally budded onto rootstocks and grown for fresh fruit or juice. Photographed in Colombia.