Roots, Stems, and Leaves as Human Food

The Role of Angiosperm Plant Parts in Agriculture and Gardening

Aug 31, 2009

"This cabbage, these carrots, these potatoes, these onions all will become me. Such a tasty fact!" (Mike Garofalo)

Nutritionists recommend that we consume many plant organs daily. They are, of course, referring to the benefits of including vegetables in our diet.

Botanically speaking, vegetables are edible parts of the vegetative plant body: roots, stems, and leaves while fruits and the seeds they contain develop from the reproductive structures of the plant.

Roots as Food

Carrots.The average American consumes nearly ten pounds of this popular vegetable per year. Carrots contain sizable amounts of potassium, calcium, phosphorus, and sugar (making them a key ingredient in many desserts, such as carrot cake).

However, the most important dietary nutrient found in carrots is what gives them their orange color in the first place – the pigment beta-carotene. Beta-carotene is converted into vitamin A, a vitamin with many functions in the human body.

Radishes.Today radishes are recognized as small spicy roots used to garnish salads but in the past radishes were enormously large, mild-tasting vegetables that were cooked. Because they could be easily stored in root cellars through the winter, they came to be known as winter radishes. Present-day radishes, known as summer radishes, first appeared in the eighteenth century.

Americans are most familiar with the small red globe-shaped varieties but radishes come in a wide range of shapes, colors, and sizes. The Japanese daikon, a staple of Oriental cuisine, is white, carrot-shaped, and grows 18 inches long. The Japanese have over 100 ways of preparing daikon.

In Mexico, the radish is honored with a festival. On December 23rd in Oaxaca City, they hold “La Noche de Rabanos” (The Night of the Radishes) in which radishes are carved into detailed figures and arranged into dioramas depicting historical or religious events.

Beets, turnips, sweet potatoes, and rutabaga (a medieval cross between a cabbage and a turnip), though not as popular as carrots and radishes, are also roots consumed as food in this country.

Stems as Food

Humans prize relatively few true aerial (above ground) stems for food. The list is short and would include mainly asparagus and kohlrabi. Actually, it is the underground stems that capture the most gastronomical attention and the favorites are clearly the potato and the onion.

Potato.This bushy, herbaceous (not woody) annual traces its origins back to the Andean highlands of South America where it was cultivated as early as 8,000 years ago.

The part humans eat and call the potato is actually a tuber, the enlarged storage tip of an underground horizontal stem known as a rhizome.

Potatoes are rich in carbohydrates and virtually fat-free (if not topped with butter and sour cream or if not fried),have no cholesterol, and are good sources of potassium, iron, a number of B vitamins, and vitamin C.

Onions.The genus Allium (part of the Lily family) is not only the source of the familiar onion but also other zesty herbs such as garlic, leeks, shallots, and chives. The onion produces a single, large fleshy bulb prized not only for culinary uses but for medicinal purposes as well.

Wild onions grew in North America long before any foreign settlers arrived. Native Americans ate them raw and dried them for food during winter months. The first big yellow onions may have come over on the Mayflower in 1620 and in a short time no colonial garden (and few modern gardens) were without them. George Washington said they were his favorite food and the cowboys of the wild west liked them in their campfire stew nicknaming them “skunk eggs.”

Leaves as Food

While true aerial stems may be a rarity in our diet, edible leaves are a different story. While humans happily gobble through mounds of spinach, cabbage, and brussel sprouts, lettuce is the leaf closest to humankind’s heart and stomach.

Lettuce is the national favorite cold vegetable. However, this passion is not unique to modern times as the ancient Romans traditionally began their feasts with a salad of lettuce. Beside lots of dietary fiber, lettuce contains some vitamin A, calcium, and vitamin C.

Lettuce came to the New World with Columbus, who planted some in the West Indies in 1493. By the 1880s there were over 100 different varieties available in the United States, most of which are still available in seed catalogs today.

There are three basic types of this leafy vegetable: head lettuce, such as iceberg, which forms a dense, tightly packed ball of leaves, looseleaf lettuce, such as redleaf and green leaf, with ruffled leaves forming a loose cluster, and cos, such as romaine, which forms an upright cylindrical head composed of long leaves.

When one closely inspects the food connection between humans and angiosperms, it becomes clear that without the flowering plants and their many edible parts, humankind simply could not exist.

The copyright of the article Roots, Stems, and Leaves as Human Food in Ethnobotany is owned by Dennis Holley. Permission to republish Roots, Stems, and Leaves as Human Food in print or online must be granted by the author in writing.