FERNS, FOSSILS AND FUEL 
Cotton ( Gossypium herbaceum) and Tree Cotton 
(Gossypium arboreum ): Cotton, though mainly valu¬ 
able as raw material for clothing, also yields a valuable 
food oil from its seeds. The herbaceous type was culti¬ 
vated in ancient Persia, where the observant Greeks noticed 
it at the time the of the expeditions of Alexander. Al¬ 
though the southern United States has become the greatest 
cotton growing region in the world, the plant does not ap¬ 
pear to have been introduced into America until long after 
the discovery of the New World, coming probably from 
southern Europe. As late as the year 1774, only two 
years before the Declaration of Independence, a bale 
of American-grown cotton was confiscated at Liverpool 
on the ground that the cotton plant did not grow in 
America. 
The tree cotton is a native of tropical Africa, and 
appears to have been known to the Romans in the time 
of the Empire. 
There is, however, a purely American branch of the 
cotton family. This is the Barbados cotton ( Gossypium 
barbadense) . At the time of the discovery of America, 
the Spaniards found it under cultivation, from the West 
Indies to Brazil and from Mexico to Peru. 
Coffee ( Coffea arabica) : To this plant the world is 
indebted for its most popular breakfast beverage. Ap- 
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