Part Four of the Series
by Richard L. Thornton, Architect & City Planner
These indigenous plants of North America are not members of the potato family, but a close cousin of wild sunflowers and daisies. Both were once a very important crops, cultivated solely by Native Americans. They have become important sources of oil and animal feed in many parts of the world.
Jerusalem artichokes (Helianthus tuberosus) grow wild in meadows and along the edges of cultivated fields throughout temperate regions eastern North America. Particularly in the upper Southeast, Middle Atlantic and lower Midwestern states, where sedimentary rocks underlay the soil; this perennial flower can take over under-grazed pastures.
When I first moved to my colonial farm in the Shenandoah Valley of Virginia, the upper pastures were completely covered with feral Jerusalem artichokes. In the late summer and early autumn, the masses of miniature sunflower blossoms on six to eight feet tall stalks created a sea of yellow-gold across the landscape.
Prior to the introduction of maize (Indian corn) from Mexico, Jerusalem artichoke tubers were a primary source of carbohydrates for Native Americans. Even after maize cultivation predominated, patches of Jerusalem artichoke plants were maintained to provide variety to diets and act as an emergency food source. The indigenous plant was far more resistant to insects and droughts than maize. In North America, Europe and Asia improved varieties are being grown again for food production, alcoholic beverages and ethane alcohol for fuels.
Traditionally, the plant’s tubers were eaten raw or cooked by Native Americans, in a manner similar to true potatoes that are indigenous to the Andes Mountains of South America. If kept dry, they did not deteriorate during the winter months. They could be carried by hunters and traders in pouches to be boiled over camp fires. The dried tubers were also crushed and ground to make flour for thickening stews and grilling pancakes.
Today, the most important dietary use of Jerusalem artichokes is in the manufacture of pasta for persons intolerant to wheat products, or who prefer the flavor of “artichoke” noodles. Home gardeners raise them for both a substitute for water chestnuts and as a less “starchy” alternative to potatoes. They can be baked, boiled, sautéed or fried, just like true potatoes. Thin sliced Jerusalem artichokes are also used in salads and Chinese dishes.
The plant’s inappropriate name came from two different sources. In the 17th century, French explorer, Samuel Champlain, sent samples of its tubers back to France, with a note that they tasted like artichokes. The plant was soon being grown in several parts of Europe, especially Italy, France and Germany. The Italians called this new crop and its cousin, the sunflower, giriosale. Over time, English speakers slanged the Italian word into Jerusalem. Other names today include Indian potato, sunroot, sunchoke and earth apple.
Helianthus annuus, the common sunflower, is a large annual flower-bearing stalk of the genus Helianthus. It is grown as a crop for its edible oil and edible fruits. This domesticate sunflower species is also used as wild bird food, as livestock forage (as a meal or a silage plant), in some industrial applications, and as an ornamental in domestic gardens.
It was long assumed that the Sunflower was first domesticated around 2300 BC in the present-day United States. Now that assumption is a subject of controversy. The plant was definitely domesticated by indigenous North Americans in eastern North America . . . probably in the Tennessee River Valley of Eastern Tennessee or the Cumberland River Valley of Middle Tennessee. However, there may have been two separate domestications.
Sunflower seeds, similar genetically to modern sunflower seeds, were found in the State of Tabasco, Mexico at the San Andres Archaeological Zone. They were radiocarbon dated to 2600 BC. There is an important difference, however, between the sunflowers of the United States and Tabasco. The southern Mexican sunflowers are tropical plants that thrive in flat, damp soil. The Southeaster sunflowers are temperate climate plants that even thrive in the rolling prairies and dry steppes of latitudes farther north than their original habitat.
Sunflower oil, extracted from the seeds, is used for cooking, as a carrier oil and to produce margarine and biodiesel, as it is cheaper than olive oil. A range of sunflower varieties exist with differing fatty acid compositions; some “high-oleic” types contain a higher level of monounsaturated fats in their oil than even olive oil. The oil is also sometimes used in soap.
The cake remaining after the seeds have been processed for oil is used as a livestock feed. The hulls resulting from the dehulling of the seeds before oil extraction can also be fed to domestic animals. Some recently developed cultivars have drooping heads. These cultivars are less attractive to gardeners growing the flowers as ornamental plants, but appeal to farmers, because they reduce bird damage and losses from some plant diseases. Sunflowers also produce latex, and are the subject of experiments to improve their suitability as an alternative crop for producing hypoallergenic rubber.
Wild Helianthus annuus is a widely branched annual plant with many flower heads that are much smaller than a domesticated sunflower. Wild sunflowers can cross with feral Jerusalem artichokes, creating hybrids that share characteristics of both plants. The domestic sunflower, however, often possesses only a single large flower head atop an unbranched stem.
Native American origins and cultivation
Although the Jerusalem artichoke is often called the “Indian Potato” in the United States, the ancestor of the “true” cultivated potato (Solanum tuberosum) is a wild, perennial plant growing in southern Peru and northwestern Bolivia. It is a member of the nightshade family that includes tomatoes and peppers. Species of wild potatoes grow throughout the Americas, including the United States, but recent genetic studies have confirmed an Andean origin for all modern, cultivated potatoes. About 7-8,000 years ago the indigenous people of the Andes began selectively cultivating this wild perennial. Over the centuries, the cultivated varieties became annual crops, dependent on man.
The wild ancestor of the Jerusalem artichoke was a common forbear to both the sunflower and the Jerusalem artichoke; probably resembling a small Jerusalem artichoke plant. The indigenous people of the Southeast probably began selective cultivation of this plant about 5-6,000 years ago. Over time, two distinct plants were developed. One (the sunflower) was cultivated for its seeds. The other (Jerusalem artichoke) became a crop cultivated for its tubers.
Although the interiors of the tubers look like the potato, their chemical composition is quite different. The members of the daisy-sunflower family do not store starch in their tubers, but a chemical called inulin. After harvesting the inulin begins chemically changing to fructose sugar. After a period of dry, cool storage, the tubers will have a sweet, nutty taste because of the fructose. This fructose was fermented by Native Americans to make a type of wine. Today, some distillers in France and Germany make brandies or beverages similar to vodka from the Jerusalem artichoke roots.
True potatoes are difficult to store for long periods outside the dry, cold climate of the Andes. They will either mold or sprout inside contemporary North American homes in a matter of a few weeks.
Although much smaller in size than true potatoes, Jerusalem artichoke tubers offered distinct advantages to Native Americans, especially those who moved between seasonal village sites. The plant is still a perennial. It is not dependent on humans for its existence. A bed of Jerusalem artichokes could be established at autumn or winter village sites. It would be a dependable source of nutrition with minimal attention from humans. Diluted urine and detritus from communal feasts were used to fertilize the beds. Otherwise, they needed no cultivation and emitted chemicals that kept away intrusive weeds. The Indian potato patches were usually established on fertile, well-drained soil as boundaries between cultivated fields and forests.
The ability of Jerusalem artichoke plants to survive without man’s intervention has made them one of several plants, formerly cultivated by the indigenous peoples of the Southeast, to now be viewed as nuisance weeds. Outside the remnant Native American population, few people are aware that the tall, colorful plants produce edible roots. They are often assumed to be wild cousins of the sunflower that choke out all competing vegetation on land formerly used as gardens or pastures.
In recent years, the Jerusalem artichoke’s hardiness and immunity to parasitic insects has brought the the attention of agronomists in North America. The plant does not require the intensive spraying of insecticides like maize (American corn.) It potentially could be grown to produce the ethanol now being added to gasoline in United States. Nutritionists are also studying expanded uses of gluten-free Jerusalem artichoke flour for commercially processed foods that now utilize wheat flour.
Whether or not North American farmers again embrace the Jerusalem artichoke as a major crop, it is almost certain to be around for a long, long time. This tall flower is a proven survivor.