RUE FAMILY (RUTACEAE) 

 97. Naranja agria, sour orange 



Citrus aurantium L.* 



Sour orange differs from the other citrus fruits 

 in: (1) the round orange or reddish-orange fruit 

 21^-4'^ inches in diameter, often bi'oader than 

 long, more or less roughened, with thick peeling, 

 and hollow pulpy core, which is bitter and too sour 

 to be edible; (2) strongly fi'agrant large white 

 flowers with usually 5 petals; and (n) leaves ovate, 

 more or less long-pointed at apex and tapering or 

 rounded at base, the petioles with lu-oad wmgs 

 %-% inch across. 



A small aromatic evergreen tree 15-30 feet high, 

 with rounded crown. The bark is brown and 

 smoothish, the inner bark light brown and bitter. 

 Twigs green, angled when young, with sharp 

 spines becoming 1 inch long. 



Leaves are alternate on petioles %-lV2 inches 

 long. Blades are jointed with petiole, ovate, 21/^- 

 51/^ inches long and l^'o—^ inches wide, with many 

 minute rounded teeth at edges, a little leathery, 

 with numerous tiny gland dots, above green and 

 slightly shiny, and beneath pale light green. The 

 leaves have a pleasant scent. 



There are 1 to few fragrant large white flowers 

 at base of a leaf. Calyx is light green and 4-5- 

 toothed; usually 5 narrowly oblong white gland- 

 dotted petals about % inch long; 20-24 stamens 

 united into tube in lower half; and pistil on a disk 

 with 9-12-celled ovary, style, and rounded stigma. 



The fruit (berry or hesperidium) rind, 1/4-% 

 inch thick, is bitter and aromatic, and the flesh has 

 bitter walls. The whitish seeds are flattened, 

 marked with I'idged lines, and about ^2 inch long 

 (1,600 to a pound). Flowering throughout the 

 year. 



Tlie heartwood is whitish to light yellow, hard 

 and fine-grained, with prominent gi'owth rings. 

 It is reported that the wood is like that of sweet 

 orange or china (Citrus sinensi'i L.*) and perhaps 

 is suitable for the same purposes. In Cuba tJie 

 wood is used to make baseball bats. 



The peeling with pulp of this species is the prin- 

 cipal source of orange marmalade and is sometimes 

 candied and, when fresh, yields an essential oil. 

 The juice serves for seasoning foods, such as soups 

 and meats, and .sometimes as an orangeade drink 

 when sweetened with sugar. A perfume, oil of 

 neroli, is produced in southern Europe from the 

 petals. In home medicines the juice is an anti- 

 septic and hemostatic, and a decoction of the leaves 

 induces sweating. The peel and its oil have been 

 used medicinally as a source of vitamins. This 

 is a honey plant also. 



Being resistant to the root rot disease of citnis 

 fruits, this species is employed, especially in the 

 United States, as the stock for budding the other 

 species. 



Cultivated in Puerto Rico and spontaneous after 

 planting and naturalized, chiefly in the lower 

 mountain and moist limestone forest regions. A 

 hybrid or variety of the Seville orange, which has 

 sweet juice, is grown in Puerto Rico also. St. 

 Croix, St. Thomas, and probably others of the Vir- 

 gin Islands. 



Public forests. — Carite, Guajataca, Luquillo, 

 Rio Abajo, Toro Negro. 



Range. — Native of southeastern Asia. Widely 

 planted and naturalized in tropical and subtropi- 

 cal regions. Naturalized in southeastern United 

 States (Georgia and Florida), Bermuda, through 

 West Indies, and from Mexico to Argentina. 



Other common names. — naranja agi'ia, naranja 

 acida (Spanish) ; naranja cajera (Venezuela) ; 

 naranjo amargo (Argentina) ; sour orange, Seville 

 oi-ange (United States, English) ; bitter orange 

 (Bermuda, Jamaica) ; bigarade orange (Ja- 

 maica) ; orange sure (Haiti) ; orange siire, orange 

 amei-e, orange grosse-peau (Guadeloupe) ; bois 

 d'oranger, naranga (French Guiana) ; laraha, 

 laraha zier (Dutch West Indies) ; laranjada terra, 

 laranja amarga (Brazil). 



Botanical .synonyms. — Citrus vulgaris Risso, 

 C. higaradia Loisel. 



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