The grapefruit (Citrus × paradisi) is a subtropical citrus tree known for its sour to semi-sweet fruit. Grapefruit is a hybridoriginating in Barbados as an accidental cross between two introduced species, sweet orange (C. sinesis) and pomelo or shaddock (C. maxima), both of which were introduced from Asia in 17th century.

The evergreen grapefruit trees usually grow to around 5–6 meters (16–20 ft) tall, although they can reach 13–15m (43–49 ft). The leaves are glossy dark green, long (up to 15 centimeters (5.9 in)) and thin. It produces 5cm (2 in) white four-petaled flowers. The fruit is yellow-orange skinned and generally an oblate spheroid in shape; it ranges in diameter from 10–15cm (3.9–5.9 in). The flesh is segmented andacidic, varying in color depending on the cultivars, which include white, pink and red pulps of varying sweetness (generally the redder varieties are sweeter).