By
Jamie Barger
jbarger@lhup.edu
This website is devoted to leaves, stems, and roots that we use for food. In addition to talking about the foods that we eat from leaves, stems, and roots, I will also discuss several social issues that have had an impact on our culture and the foods that we eat.
Many of these plants produce both a leafy crop and a root crop. Overall leafy vegetables contain few calories, very little protein and are consumed primarily in salads or "additions to meals." You can also use the leaves of plants as pot herbs, or seasonings on food. Roots have higher caloric value but they are low in carbohydrates.
Many common vegetables come from leaves. Some popular vegetables are cabbage, kale, lettuce, and collard greens, to name a few. Many of these vegetables are primarily used when making salads. Leafy vegetables are good sources of protein, fiber, minerals (such as: calcium, iron, magnesium, and phosphorus), vitamins (such as: A, C, and B-complex), while being low in carbohydrates and fat. The first leafy vegetable I am going to discuss will be lettuce.
Lettuce
Lettuce is primarily grown in Mediterranean areas. There are two main forms of lettuce, head lettuce and leaf lettuce. With head lettuce the leaves form into a ball or head as the plant matures, while leaf lettuce makes no attempt to bunch together as the plant grows. The growing season for leaf lettuce usually falls between May and the end of June. Currently, lettuce is the vegetable imported in the largest volume and has the largest dollar value of any vegetable imported into the Atlantic Area. It is mostly marketed through roadside Farmer's markets or deliveries to direct retail stores as well as deliveries to wholesalers. Lettuce contains useful amounts of nutrients, including Vitamins A and C, and the minerals, calcium and iron. It can generally be stored for two to three weeks, as long as it is stored at 0oF.
Kale
Kale is a loose-leafed, edible plant from the cabbage family, in fact it is one of the earliest members of the cabbage family to be cultivated. This vegetable is also native to the Mediterranean region, also considered, primitive cabbage or even a rutabaga. There are two main forms of kale: B. Oleracea and B. o. Alboglabra. The B. oleracea is the wild ancestor of cabbage, broccoli, brussels sprouts, kohlrabi, and cauliflower and native to the Atlantic and Mediterranean coasts of Europe. The Alboglabra group includes white-flowered Chinese kale and is native to Southeast Asia. This vegetable also contains more Vitamin C than any other leafy green. Kale is also high in fiber and has a reputation for containing anti-cancer properties. You can primarily find this used in dishes in the South.
Cabbage
There are stories from Greek mythology that tells us that cabbage sprang from the fallen tears of a Thracian King who was about to be killed by Dionysus (The Wine God) for uprooting some of his favorite grapevines. During Roman times cabbage was relatively expensive that was primarily used in the dish we know as corned beef and cabbage. By 15th century, cabbage was widely cultivated in Europe and ended up coming to North America with the early settlers. European peasants have always considered this an important part of their diet. Cabbage could be harvested late in the fall and stored for a rather long period of time. Also, cabbage was shredded, mixed with salt in earthenware crocks, and allowed to ferment into sauerkraut, mainly as a method of preservation. There are many different types of green cabbage, such as: Polar Green, Green Express, Charmant, Sunup and Belbro. In addition to green cabbages there are also red cabbages. Some common types of red cabbages are: Ruby Ball, Red Acre, and Red Perfection. Cabbage is easy to grow, inexpensive, tolerates the cold, and keeps well. This vegetable is rich in Vitamin C and fiber, keeping cabbage cold helps to keep the Vitamin C in the leaves. Having cabbage frequently in your diet may help reduce the risk of certain cancers, such as colon and rectal cancer. However, people with thyroid problems should avoid eating large amounts of cabbage, it interferes with the body's absorption of iodine, which is needed by the thyroid gland.
A split head of cabbage.
Collards
Collards, also known as collard greens, are also members of the cabbage family and have a taste similar to cabbage and kale. They are grown in the southern part of the United States, especially in Mississippi and can also be found in Europe. Portugal is a country that uses collards quite frequently in their cooking. Popular means of eating collards are to steam, boil, or microwave them, they like to add them to soups and stews, and sometimes to cold salads. When cooking you can substitute collards in recipes that call for cabbage or kale. These vegetables are also a healthy addition to your daily diet, they contain no fat or cholesterol and are low in sodium. They are a good source of Vitamin A and C, as well as iron and ascorbic acid.
Burdock
More commonly this vegetable is known as burdock
root, cocklebur, or burrseed, while in Japan it is called gobo. It
originally started out in Siberia, but is more commonly cultivated in Japan and
is slowly spreading to some areas of the United States as well as Europe.
Burdock is a dark, woody-looking root, with bark like skin that looks thick,
when in actuality it is tissue-paper-thin. Underneath this unappealing
exterior, is a sweet, nutty, delicate, crunchy flesh. Sometimes considered
to be a healing vegetable, burdock is high in fiber and low in calories, a good
source of potassium and moderate source of iron and calcium. This
vegetable also contains a high quantity of inulin, a naturally occuring
phytochemical that mimics the actions of insulin and people have used it to
control hypoglycemia and pre-diabetes conditions. This was an important
winter food for the Iroquois. They dug it in the fall, dried it, and then
ate it throughout the long cold months of winter. This plant grows
underground and can be over four feet long. The root is usually sliced and
steamed as a vegetable would be and the taste is described as "a sweet, earthy
flavor with a tender-crisp texture."
Horseradish
Horseradish is thought to be of
Mediterranean or Eastern European origin, and is now wid
ely cultivated in
Central and Eastern Europe. In Japan, horseradish is more commonly known
as wasabi. (Doesn't that clarify the Barenaked Ladies song lyrics "...hot
like wasabi...") Due to the interaction of sinigrin and myrosin, the pungent
aroma is created as well as the hot, biting taste. These two components
are not mixed while the root is intact, however after scrapping or cutting the
root they are free to interact. (Sinigrin, which contributes to the
potency of mustard as well, is similar to the chemical responsible for the
caustic effects of mustard gas. Mustard gas is a poisonous used in
chemical warfare during World War I and during the Iran-Iraq war of the 1980's.)
The Below ground the roots grow deep and aggressively - resembling large,
misshapen carrots, while above ground there are leaves that can reach a length
of three feet and are usually in clumps, occasionally the plants sometimes
produce white flowers as well. The word "horseradish" is believed to denote
large size and coarseness, while "radish" comes from the Latin radix, meaning
root. Horseradish is a very popular spice in Central and Northern Europe,
where they grate the fresh root and put it on ham or roast beef and it is a
tradition in Austria to eat ham with horseradish at Easter time. However,
this plant has a longer history of medicinal purposes than its use as a
condiment.
Kohlrabi
Kohlrabi also means "cabbage turnip" -
kohl meaning cabbage and rabi meaning turnip. This plant has
the same shape as regular cabbage, however the bulb of the plant grows
underground, while the stem and leaves grow above ground. Since around the
16th century this plant has been known in Germany, England, Italy, Spain,
Tripoli, and the eastern Mediterranean. Overall this plant is easy to grow
,
productive, and an ideal garden vegetable, provided you do not plant too much of
it. It has a taste similar to a turnip, only sweeter and more mild, as
long as the vegetable is harvested at the right time - before it becomes too old
and tough. There are two main types of kohlrabi grown in the United
States, white and purple. The white is actually light green and the more
popular of the two types.
Manihot
Manihot is also more commonly known as the cassava, yuca, or the manioc. Cassava is a perennial woody shrub grown as an annual and a major source of low cost carbohydrates for populations in the humid tropics. The reason for being grown is due to the enlarged starch-filled roots thatcontain the maximum concentration of start on a dry weight basis among food crops. However, the roots contain very little protein. It is recommended that you cook cassava because there are potentially toxic concentrations of cyanogenic glucosides. You can cook these roots much like a potato - they can be boiled, baked, or fried and cooking them reduces the levels of cyanogenic glucosides in the vegetable. In traditional settings of the Americas, the root is grated and then the sap is extracted through squeezing or pressing, where the leftover vegetable is then dried over a fire. Later, if you wish to, you can re-hydrate the vegetable with water or add it to soups or stews. In Africa they do things a little differently with this root. First they ferment the root in water, then they either sun dry them for storage, or grate them and use them to make a dough that is then cooked. (You can also make alcoholic beverages from these roots.) Roots can be peeled, grated and washed with water to extract the starch which can be used to make breads, crackers, pasta and pearls of tapioca. Fresh roots can be sliced thinly and deep fried to make a product similar to potato chips. They can be cut into larger spear-like pieces and processed into a product similar to french fries. The shelf life of cassava is only a few days unless the roots receive special treatment. Removing the leaves two weeks before harvest lengthens the shelf life to two weeks. Dipping the roots in paraffin or a wax or storing them in plastic bags reduces the incidence of vascular streaking and extends the shelf life to three or four weeks. Roots can be peeled and frozen. Traditional methods include packing the roots in moist mulch to extend shelf life.
This plant was originated in Brazil and Paraguay, thus far no wild forms of cassava are known. Brazil is the leading producer of this plant followed by Thailand, Nigeria, Zaire, and Indonesia. However, production in African and Asia is starting to increase. This plant made its way to Africa by Portuguese traders from the Americas, and is now a staple for many parts of western and central Africa.
Potatoes
Potatoes come in two basic forms, "white potatoes" and "sweet potatoes." However, I am just going to get into white potatoes. Mostly potatoes are associated with Ireland and Idaho, although its origins can be traced back to the Andean highlands of South America. Indians collected wild potatoes as early as 8,000 years ago, from the Andean plateau. By the 1530's, when Francisco Pizarro arrived, the potato was the staple of the Incas. Even though the Spanish were attracted to the Incan gold, silver, and jewels, they later realized that potatoes were the real prize. Eventually the potato made its way to Spain and then slowly spread throughout Europe. At first the potato was grown in Europe as food for livestock and only became accepted as food for people in the 18th century. The potato was most widely accepted in Ireland and was established as a crop in early 1625 as a dietary staple for the Irish peasants. Unfortunately, Ireland later experienced problems with their potato crops.
The Irish Potato Famine started in 1845 and caused over one million people to die or emigrate. Within a decade, the population of Ireland declined from eight million to less than six million people. The "white" potato, known today as the Irish potato, originated in the Andean Mountains. It is speculated that the Spanish brought the potato to to Europe in the latter half of the 16th century. At first potatoes were considered a novelty and did not become popular until the 18th century, when the monarchs of Europe realized that potatoes contained nutritional value and ordered them to be planted. By 1800 the potato had taken root and 90 percent of the Irish population was dependent on the potato as their primary source of caloric intake. The English colonization of Ireland forced the Irish to pay extremely high rents and taxes, to export their crops and to increase their dependency on the potato. From 1816 on, wet weather began destroying crops, where the potato failed in several provinces. Weakened by hunger, more than 100,000 people died of starvation and disease. In 1845 farmers noticed a funny mist that covered the sea and soon the the potato stalks were turning black. The potato crops started giving off an offensive odor that could be smelled for miles, causing a potato blight, that ended up being the Great Famine of Ireland. An airborne pathogen that spreads rapidly among crops during the right weather conditions is what caused the blight. This disease not only attacks the crops in the field, but it also attacks the crops in storage during mild and damp weather. Later it was discovered that the blight was caused by a fungus called Phytophthor Infestans. Unfortunately, a cure for this fungus was not discovered until 40 years later. In order to kill the fungus a solution of copper sulphate must be sprayed before the fungus takes root. In 1845 the potato blight destroyed 40 percent of the crop, while in 1846 the blight destroyed 100 percent of the crops. With the depleted crops and no way to plant new seeds, people were unable to pay their rent. Therefore, upon failure to pay rent, they were either jailed or evicted and their homes were burned. During this time approximately 500,000 people were evicted, many of whom died of starvation or disease, or relocated to poorhouses. Instead of being evicted, jailed, or moving to poorhouses many people opted to emigrate. This emigration continued between 1850 and the 1860's to places such as, Great Britain, United States, Canada, and Australia.
The results of the famine are still seen today - one hundred and fifty years after the event by the number of Irish descendants scattered around the world. Also, the landscape in Ireland is still marked by a lack of trees and shells of the homes that were left behind. Even today this fungus is still the leading pest for potato crops.
A picture of a blighted potato.
Prickly Pear
The prickly pear cactus is part of the family cactaceae and found in North American deserts. They have flat, fleshy pads that looks like large leaves. These pads are actually modified branches or stems that have several functions such as, water storage, photosynthesis, and flower production. Like other cactus, they have larges spines, which are actually modified leaves, that grow from tubercles. Tubercles are small wart-like projections on their stems. Prickly pear cactus also has glochids on their spines that are yellow or red in color and detach easily from the pads. This is the part that one usually finds lodged in their skin after touching the plant.
The prickly pear contains an edible fruit, sold under the name "tuna." You can also cook prickly pear branches and eat them as a vegetable - sold in stores under the name "nopalito." Both the fruit and the pads of the prickly pear cactus are rich in slowly absorbed soluble fibers that may help keep blood sugar stable.
This plant has traditionally been an important part of Mexican culture. The plant itself is called "nopal" by the locals and has been the source of legends, magic, and rituals. Today, they are still used locally for food and medicine. Prickly pear cactus contains eight essential amino acids and is effective against type II diabetes. It is also used to fight high cholesterol and the "battle of the bulge." Also, prickly pear cactus contains Vitamin B, calcium, magnesium, iron, and fiber.
http://www.tc.umn.edu/~mboucher/mikebouchweb/choctaw/swampfir.htm - A link to a legend concerning the prickly pear.
Asparagus
Asparagus is a highly productive vegetable, belonging to the lily family - which also includes onions, garlic, and leeks, when grown in the right climate. It is more suited to the cooler areas of North and West Texas. The primary reason for growing asparagus is for the stems, or spears. If you tend the plants correctly you can yield eight to ten pounds or more, per 100 square feet of bed. An interesting fact about asparagus (if one can consider asparagus interesting) is that the plant can last 15 to 25 years without replanting, if it is well cared for and the climate is suitable. In Europe, white asparagus is prized. To prevent the production of chlorophyll and keep the spears white, the asparagus beds are covered with mulch to keep out the sun. Asparagus is grown from one year-old plants or "crowns" that are usually planted in January or February. The process of growing asparagus requires three years from the time the crown is planted, in a foot of sandy soil, until the bed if in full production. Asparagus does best in a deep, well-drained soil with full sunlight. This vegetable is a nutrient-dense food that is high in Folic Acid and a good source of potassium, fiber, Vitamins B6, A and C, as well as thiamin.
Rhubarb
Thanks to the Romans, the word "rhubarb" takes its name from the Latin words rha barbarum. How this name came to be is from the banks of the river "Rha," which is the ancient name of the Volga. During this time the land was considered foreign and barbarian territory, so therefore it literally means "from the barbarian, Rha." Dictionaries first described this plant as the lovable, edible plant. Typically rhubarb is grown in cooler temperatures, which is why naturalist John Bartram found it in his travels across Siberia in the 1770's. After Bartram collected several plants he shipped them back to America, which is why we now grow the plants. Rhubarb grows long succulent tender stalks, which are usually red. Cool temperatures in the spring intensify the redness of the stalks. It is adapted to the cooler climates as it wilts and dies in the warm zones. The large leaves are heart-shaped and crinkly. Yellow-green flowers spring up in the center of the plant. Usually, the flower stems are cut back as they sap strength from the stalks. A native plant of Mongolia, the inhabitants cherish and cultivate it for the medicinal value of its roots. They brew the roots into a tea to cure almost everything that ailed the sick person. Eventually, they learned to flatten dough and lay chopped stalks of rhubarb on top of the thick dough and cook it. Thus, 'pie plant' became the code word for this early spring plant.
Overall there are many vegetables and food that come from edible leaves, roots, and stems. Throughout various cultures and countries you will find many uses for different plants. Unfortunately, it would take forever to go into great depth about every culture and all of their different plant uses. So next time you are sitting down to dinner, think about what you are eating and if you can identify what it came from, especially the vegetables. Chances are, it came from an edible, leaf, root, or stem.
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"Kohlrabi." http://aggie-horticulture.tamu.edu/plantanswers/publications/vegetabletravelers/kohlrabi.html. September 20, 2003.
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