RUTACE^ 487 



Variety and Name. — The name grapefruit is the one that 

 this species is known by commercially. Shaddock is a horti- 

 cultural variety, the fruit of which is much larger than the 

 common grapefruit. It is a coarse, thick-skinned fruit, with 

 thick, leathery septa between the locules, and is of no com- 

 mercial importance. The name pomelo is now recognized by 

 most horticulturists. Grapefruit is a well-known breakfast 

 fruit. 



CITRUS AURANTIUM (Sour or SeviUe Orange) 



Description. — The sour orange tree is 20 to 30 feet high, 

 and bears long, flexible, blunt spines; the leaves are 3 to 4 

 inches long, wedge-shaped at the base, pointed at the tip, 

 and the petioles are broadly winged; the flowers are borne 

 singly or in small axillary cymes; the fragrant glandular- 

 dotted petals are white above and below; there are from 20 

 to 24 stamens; the ovary has 6 to 14 locules; the Jruit is 

 globose, orange-colored or reddish, rough, the pulp acid, and 

 the juice sacks small and spindle-shaped. 



Geographical. — The sour orange is probably a native of southeastern Asia. 

 It is cultivated in the United States, being used as a stock on which to bud 

 other citrus fruits. 



Other Species of Citrus. — Other Citrus species of less 

 commercial importance in the United States are C. mitis, 

 the Calamondin orange, C. ichangensis , Ichang lemon, and 

 C. hergamia, bergamot. 



FORTUNELLA (Citrus) (Kumquat or Kinkan) 



Description. — The kumquats are evergreen shrubs with 

 simple, glandular" leaves; the scented white flowers are single 

 or in clusters of three or four, and axillary; the early flowers 

 in the spring are usually without pistils; there are four times 

 as many stamens as petals; the ovary has three to seven cells, 



