Jerusalem artichoke

Helianthus tuberosus is a herbaceous perennial plant growing to tall with opposite leaves on the lower part of the stem but alternate towards the top. The leaves have a rough, hairy texture. Larger leaves on the lower stem are broad ovoid-acute and can be up to long. Leaves higher on the stem are smaller and narrower. ==Culinary use==

The tubers can be eaten raw, cooked, or pickled. Before the arrival of Europeans, indigenous peoples cultivated H. tuberosus as a food source. The tubers persist for years after being planted, so the species expanded its range from central North America to the eastern and western regions. Early European colonists learned of this and sent tubers back to Europe, where they became a popular crop and naturalized there. It later gradually fell into obscurity in North America, but attempts to market it commercially were successful in the late 1900s and early 2000s.), which is a polymer of the monosaccharide fructose. Tubers stored for any length of time convert their inulin into its component, fructose. Jerusalem artichokes have an underlying sweet taste because of the fructose, which is about one and a half times as sweet as sucrose. It has also been reported as a folk remedy for diabetes: ==Etymology==

Despite its name, the Jerusalem artichoke has no relationship to Jerusalem, and it is not a type of artichoke, though the two are distantly related as members of the daisy family. The most probable explanation is that Italian settlers in the United States called the plant , the Italian word for sunflower, because of its familial relationship to the garden sunflower (both plants are members of the genus Helianthus). Over time, the name girasole (pronounced closer to in Neapolitan) was corrupted by English-speakers to Jerusalem. Various other names have been applied to the plant, such as the French or Canada potato, topinambour, and lambchoke. Sunroot is a literal translation of the Virginia Algonquian term kaishucpenauk reported in 1588, this naming is similarly reflected in Ojibwe as giizisoojiibik. Sunchoke, a name by which it is still known today, was invented in the 1960s by Frieda Caplan, a produce wholesaler trying to revive the plant's appeal. The name topinambur, in one account, is attributed to the Brazilian coastal tribe called the Tupinambá, several members of which were brought to France in 1613 at the same time that the tubers were beginning to make an appearance on French tables. The New World connections were conflated, the plant being misattributed to Brazil, resulting in the name toupinambeaux (earliest known use 1618) being applied to the tubers in French. By 1658, topinambour is found. From there, the word made its way into other European languages. ==Cultural significance==

According to Iroquois mythology, the first sunchokes grew out of Earth Woman's feet after she died giving birth to her twin sons, Sapling and Flint. ==History==

, 1880 Jerusalem artichokes were first cultivated by the Indigenous peoples of the Americas, though the exact native range of the species is unknown. Genome analysis has ruled out the common sunflower (also originating in the Americas) as an ancestor, and instead points to hybridization between the hairy sunflower and the sawtooth sunflower. The French explorer Samuel de Champlain discovered that the native people of Nauset Harbor in Massachusetts had cultivated roots that tasted like artichoke. The following year, Champlain returned to the same area to discover that the roots had a flavor similar to chard and was responsible for bringing the plant back to France. Sometime later, Petrus Hondius, a Dutch botanist, planted a shriveled Jerusalem artichoke tuber in his garden at Terneuzen and was surprised to see the plant proliferate. They have also been called the "Canadian truffle". == Invasive potential ==

Biological characteristics Its rapid growth and its ability to reproduce from buried rhizomes and tubers facilitates the Jerusalem artichoke's uncontrolled spread. The vegetative propagules can be transported via rivers and water streams and begin a new population on riverbanks. Dispersal by animal is also possible, as animals feed on tubers and rhizomes and excrete the propagules in new areas. With humans' cultivation, there is also a risk of the plant's unintended escape into the wild. It can also be propagated by seed. Its relatively long flower period enables the Jerusalem artichoke to increase its reproductive potential. Origins and distribution Originating in North America, the Jerusalem artichoke can now be found in several countries in North and South America, Europe, Asia, and Australia. In Central Europe it is one of the most expanding invasive plant species. It can grow in many geo-climatic regions and different types of soils. However, Jerusalem artichoke prefers moist habitats Suppression of other native plant species Because of its ecological and biological attributes, the Jerusalem artichoke is highly competitive with other plant species. For instance, the carbohydrates in the tubers serve as an energy source for rapid growth in spring. Therefore, the risk of outcompeting and repressing the growth of other native plants is increased. == Cultivation and use ==

Unlike most tubers, but in common with many other members of the Asteraceae (including the artichoke), Jerusalem artichoke tubers store their carbohydrate as inulin (not to be confused with insulin) rather than as starch. This has made them an important source of inulin used as a dietary fiber in food manufacturing. Jerusalem artichoke can propagate with seeds and tubers but the use of tubers leads to higher yields. For planting, the tubers are cut into pieces with three to five buds that are placed in depth in the soil. Jerusalem artichoke has low nutrient requirements and needs less nitrogen than other energy crops. The competitiveness against weeds is high, making weed control easier but also making it harder to grow a different culture afterward, since some small tubers usually remain in the ground after harvest. The plant's high competitiveness may be due to allelopathic effects, high plant size, and rapid growth rate. Crop yields are high, typically for tubers, and green weight for foliage. Tubers remaining in the ground lie dormant over winter and can handle temperatures as low as . but unlike the potato, they can also be eaten raw. They have a similar consistency and, in their raw form, have a similar texture but a sweeter, nuttier flavor. When raw and sliced thinly, they are fit for a salad. Their inulin form of carbohydrates give the tubers a tendency to become soft and mushy if boiled, but they retain their texture better when steamed. The inulin cannot be broken down by the human digestive system but bacteria metabolize it in the colon. This can cause flatulence and, in some cases, gastric pain. John Gerard's Herbal, printed in 1621, quotes the English botanist John Goodyer on Jerusalem artichokes: Jerusalem artichokes have 650 mg potassium per 1 cup (150 g) serving. They are also high in iron and contain 10–12% of the USRDA of fiber, niacin, thiamine, phosphorus, and copper. Use as forage In former times, Jerusalem artichoke was used as forage for domesticated cattle, horses, and pigs. The plant has valuable nutrient contents and various bioactive compounds, and so is used today as an animal feed source or for the health of several animal species. Pigs, for example, can eat the tuber either dried or directly from the ground or the green plant biomass (stalks and leaves) from the pasture. Washed Jerusalem artichoke tubers can be fed to many animals, and silage produced from the harvested stalks and leaves. The silage has high nutrient values and satisfactory digestion performance for ruminants. Its high inulin content beneficially affects the rumen metabolism and microflora. However, cutting the tops to produce silage greatly reduces the harvest of the tubers. There are also many other Jerusalem artichoke products on the market, such as supplementary feed for horses, dogs, and small animals. Fermented products In Baden-Württemberg, Germany, over 90% of the Jerusalem artichoke crop is used to produce a spirit called '', the German word for Jerusalem artichoke. By the end of the 19th century, the tubers were being used in Baden to make a spirit called "Topinambur-Branntwein" (Jerusalem artichoke brandy), "Topinambur" (Jerusalem artichoke), "Topi", "Erdäpfler", "Rossler", or "Borbel". Topinambur'' produced in the European Union and Switzerland must be made exclusively from Jerusalem artichokes, contain at least 38% alcohol by volume, and contain neither added alcohol nor flavorings. Caramel color is the only permitted additive. == Diseases and pests ==

Stem rot disease is caused by the fungus Agroathelia rolfsii (aka Sclerotium rolfsii or Athelia rolfsii), which is one of the most important pathogens causing tuber and stem rot and up to 60% loss in Jerusalem artichoke yield. Growing resistant varieties is an important method of controlling Agroathelia rolfsii. ==References==