Citrus vulgaris Risso, Ann. Mus. Paris 20: 190. 1813
Citrus bigaradia Loisel. Nouv. Duham. 7 : 99. 1819.
Citrus Aurantium vulgaris Wight & Arn. Prodr. 1 : 97. 1834.
Citrus Aurantium bigaradia Hook. Fl. Brit. Ind. 1 : 515. 1872.
A small tree 6-9 m. in height, the young twigs light-green, armed with sharp, alternate thorns ; leaves unifoliolate, evergreen, alternate; leaflet ovate, 6-12 cm. long, 3.5-10 cm. broad, often acuminate ; petioles commonly broadly winged ; flowers in small axillary cymes, sweet-scented, somewhat larger than those of the preceding ; sepals often bluntish ; petals oblong, white ; berry dark-orange, or frequently reddish when mature, the rind thick, more or less roughened, strongly aromatic, bitter, the pulp sour and bitter.
Type locality: (Cultivated.)
Distribution : Cultivated ; thoroughly naturalized in tropical and subtropical regions.

Citrus aurantium L,. Sp. PI. 782. 1753 A tree 6-12 m. in height, with light-green, glabrous twigs angled toward their ends, the branches smooth, grayish-brown, often armed with small, sharp thorns ; petioles commonly narrowly winged, or wingless; leaves uuifoliolate, evergreen; leaflet oblongovate to ovate or oval, 6.5-13 cm. long, 3-10 cm. broad, acute or sometimes rounded at the apex, cuneate to rounded at the base, dark -green and shining above, paler beneath, entire or crenulate; flowers very fragrant, in axillary clusters of 1-6; sepals more or less sharppointed ; petals oblong, 11-18 mm. long, pure white, thick and fleshy ; berry globose or subglobose, 6-9 cm. long, 6.5-9.5 cm. broad, the rind usually thin, smooth or wrinkled, the pulp abundant, sweet or sour.
Type locality : India.
Distribution : Widely cultivated ; naturalized in tropical and subtropical regions.