6. Citrus maxima (Burman) Merrill, Interpr. Herb. Amboin. 296. 1917.
Aurantium maximum Burman in Rumphius & Burman, Herb. Amboin. Auctuar. 7: Index . 1755; A. decumanum (Linnaeus) Miller; Citrus ×aurantium Linnaeus subsp. decumana (Linnaeus) Tanaka; C. ×aurantium var. decumana Linnaeus; C. ×aurantium f. grandis (Linnaeus) Hiroe; C. ×aurantium var. grandis Linnaeus; C. costata Rafinesque; C. decumana (Linnaeus) Linnaeus; C. grandis (Linnaeus) Osbeck; C. grandis var. pyriformis (Hasskarl) Karaya; C. grandis var. sabon (Siebold ex Hayata) Hayata; ?C. kwangsiensis Hu; C. medica Linnaeus subf. pyriformis (Hasskarl) Hiroe; C. obovoidea Yu. Tanaka; C. pampelmos Risso; C. pompelmos Risso; C. pyriformis Hasskarl; C. sabon Siebold ex Hayata.
Trees. Young branches, abaxial surface of leaves, peduncles, and ovaries pilose. Branches usually purplish, flat with ridges when young. Petiole 2-4 × 0.5-3 cm or less, winged; leaf blade broadly ovate or elliptic, 9-16 × 4-8 cm or larger, thick, dark green, base rounded, apex rounded to obtuse and sometimes mucronate. Flowers solitary or in racemes; flower buds purplish or rarely milky white. Calyx 3-5-lobed. Petals 1.5-2 cm. Stamens 25-35, some undeveloped. Style long and thick. Fruit pale yellow and yellowish green, globose, oblate, pyriform, or broadly obconic, usually more than 10 cm in diam., with large prominent oil dots, to 200-seeded or seedless; pericarp spongy; sarcocarp with 10-15(-19) segments, white, pink, reddish, or rarely milky yellow. Seeds irregularly shaped, with conspicuous ridges, undeveloped seeds numerous; embryo solitary; cotyledons milky white. Fl. Apr-May, fr. Sep-Dec. 2n = 18, 36.
Cultivated and naturalized in S China [probably native to SE Asia].
Pomelo or shaddock includes cultivars with round to obovoid fruit much favored for festival decoration as well as eating. No truly wild plants (presumably with much smaller fruit) have been seen. Citrus maxima is a parent with C. reticulata of C. ×aurantium.