SWEET POTATO.
The Spanish name, Patata, comes from the Peruvian, Papa, name of a wild morning-glory, native to tropical South America, and China. The Spaniards learned to eat the sweet tubers that the Incas cultivated on the west slopes of the Andes. They are now grown in the warm parts of all countries, 'including the East and West Indies. China cultivated the vegetable some centuries before the Christian Era, so we can hardly claim it exclusively as an American plant. It is one of those cosmopolitan "weeds," whose value was independently discovered on both sides of the globe, by hungry, primitive men, who nib bled any fleshy root that tasted good, and laid it on the fire to soften it by roasting or parching. The next step was to cultivate it. So the size of the tubers has been increased and improved by selection and better tillage, until we have almost one hundred varieties to choose from, and tubers weighing from one to twelve pounds are produced.
The range of this tropical plant has been ex tended until any region that has a growing season of four months free from raw winds and frost, can raise the crop. The best soil is a loose, sandy loam, well-drained. Growth must proceed with out interruption.
The sweet potato plant is a creeping vine, related to the bindweed, dodder, cypress vine, and morn ing-glory, as its coiling stems and trumpet-shaped flowers prove. The seeds are borne in dry, two celled capsules, more familiar to us in the morning glory and moon-flower. Underground, the sweet potato forms the tubers, which are true roots, not stems, as in the "Irish" potato. No eyes are seen on the sides or ends of the sweet potato, but fibrous roots instead. The grower puts the tubers into a bed of sand to sprout fully assured that buds will be formed, and stems rise. This pecul iarity of a root tuber, the formation of buds, is not commonly met with. It is found in raspberry and apple and other fruits. Plant a bit of root, and a shoot rises to form a new plant. Cut down and try to destroy some trees, and leafy shoots rise from the tips of roots left in the ground. All
such plants arise from buds that are called adven titious, and occur without definite order. They are abnormal and unusual. The sweet potato has come to be propagated by this method of root cuttings.
The sweet potato is rich in starch and sugar and has a distinctive flavor that makes it a favorite root vegetable in many lands. The Northerner likes it to come to the table mealy and dry; the Southerner likes it waxy, or even sticky. A favor ite Southern mode of cooking serves the "yam" in a syrup. Up North, butter and salt season it to taste. So the Southern grower is disappointed, if he sends any but dry, mealy varieties to Northern markets.
Quantities of sweet potatoes are canned. Some are evaporated. Sweet potato meal, glucose and even alcohol are commercial products. The vines are cured and fed as hay. Small and damaged tubers are fed to stock. Bruising and cutting must be carefully guarded against in digging the crop, for the soil is full of fungous germs, and decay is quickly started in a tuber with skin broken.
We are fortunate to have this vegetable as a staple crop. In England it is not grown; a few varieties are hardy around Paris. The Europeans who have learned to like them must depend on imported potatoes. Of our great crop, a small part is sent abroad. The North African states send their surplus to European cities.
"Yam" is a Southern name, applied locally to some yellow-fleshed varieties of sweet potato. "Potato" is the name used in the West Indies. "Irish," or "white" potatoes, the true potato is called to distinguish it.
The true yam is a root tuber, like our sweet potato in composition and mode of growth, but belonging to an entirely different family. It originated in China, and from there has been introduced into Europe. It is hardy and whole some. Its fault seems to be that the tubers go so deep that they are difficult to lift when mature. They are not yet a market vegetable in the United States, though a few amateurs grow them.