DICOTYLEDONS: ARCHICHLAMYDEA 299 
been developed, more for what are called dessert purposes 
than for wine and raisins; and this culture has reached its 
highest perfection in New York, New Jersey, Maryland, 
Virginia, and Ohio. No cultivated plant is attacked by 
more diseases than the grape, nor have any plant diseases 
been more fully studied. 
(4) Crrrous rruirs.—These fruits all belong to a sin- 
gle genus (Citrus), whose species are shrubs or small trees, 
natives of tropical and subtropical Asia (China-India). 
The citrous fruits are numerous, but the three forms chiefly 
cultivated in the United States and common in markets are 
as follows: 
Oranges are extensively cultivated in the United States 
in central and southern Florida, the delta region of the 
Mississippi, and California. All the varieties are derived 
from a single species (Citrus Auranttum), and may be 
grouped as bitter oranges and sweet oranges, the latter 
being the chief market form. The very popular seedless 
navel oranges of California were introduced in 1870 from 
Brazil by the United States Department of Agriculture, 
being a chance seedling variety. 
A closely allied species (Citrus nobilis) produces the 
varieties of mandarin or kid-glove oranges. True mandarins 
are small and light orange in color, and are not so much 
prized in market as the dark orange or reddish forms known 
as tangerines. 
Grape-fruits are extensively cultivated in Florida and 
California, all the varieties, most of which have originated 
in Florida, coming from Citrus Decumana, a native of the 
Malayan and Polynesian Islands. The original and best 
name for this fruit is pomelo, although it is sometimes called 
shaddock as well as grape-fruit. In reality, the pomelo or 
grape-fruit is the common round-fruited form of the 
markets, while the shaddock is a very different plant with a 
pear-shaped fruit. 
