Chinese traders exploring the South America's, came across the sweet potato took it home with them, and later to the Ryukyu Islands, where it became the basic food of the people.
It spread from the Philippines all over the East Indies, and in a short while was the principal food of many tropical islands.
The sweet potato reached Africa through numerous introductions on both coasts, and was early cultivated in parts of India.
The sweet potato is a better food than the potato, as it provides not only starch but also has more protein and also contains sugar.
The sweet potato is not a yam, which is a strictly tropical plant belonging to an entirely different family.
The only bean known to our European ancestors was Vicia faba, the faba of the Romans, with seeds of rank and indifferent flavor.
This is the bean that Capt.
Jinks fed to his horses in the old song, and is the broad or Windsor bean of England.
It is grown for green manure in California, and by a few Italians and Portuguese in their family gardens, but is unknown to most people in this country.
None of the savory and nourishing beans cultivated in the United States, and now known all over the world, were a part of European diet before the time of Columbus.
Four species of beans native to the American tropics were cultivated for their seeds or seed pods in pre-Columbian times.
All our common bush and pole beans are variants of Phaseolus vulgaris, and were grown practically all over North and South America in prehistoric time.
The cultivation of corn and beans went together.
By selection the range of beans has been greatly extended, and, for instance, England no longer depends on France for the haricot, or French bean grown successfully in England for a long time.
Lima beans, Phaseolus lunatus, are native to Brazil, but Europeans met them first in Peru.
In pre-Columbian times they were cultivated from Peru to the southern United States.
The Amerinds not only had our common, climbing, large, white-seeded lima beans but also had speckled, pure red, and black-seeded kinds, dwarf lima beans, small-seeded kinds, and others that we do not have.
The lima bean was soon carried to Africa by slavers, to the Philippines by Aztecs, to the East Indies by Portuguese, and is now found in most warm temperate and tropical regions.
The scarlet runner, Phaseolus multiflorus, is not only a good food plant but is also cultivated as an ornamental for its large, brilliant, scarlet flowers.
It is a native of tropical Mexico, but is now distributed all over the world wherever climate permits.