January 21, 2018
Cut Malanga on a wood cutting board close view

Roots and Tubers: Nature’s Buried Treasures

by Berkeley Wellness  

Hearty and nourishing, roots and tubers have been important foods for thousands of years. Known as nature’s buried treasures, roots and tubers are geophytes, a botanical term for plants with their growing point beneath the soil.

Roots are parts of a plant that usually grow downward, anchoring the plant into the ground, where they absorb moisture and nutrients. Examples of root vegetables include beets, carrots, celeriac, parsnips, sweet potatoes, and turnips.

Tubers form at the base of roots, and store energy in the form of starch to support new stem growth for the plant. Examples of tubers include potatoes, Jerusalem artichokes, jicama, and yams.

With wildly varying characteristics, and flavors ranging from earthy to sweet, roots and tubers are arguably the most nutritious, economical, and versatile foods.

Roots and tubers: nutrition

Because these vegetables are so diverse, their nutritional make-up is highly varied. For the history and nutritional profile of the most commonly eaten roots and tubers, see these listings:

Other types of roots and tubers

Arrowroot (arrowhead, fung quat): Also called a Chinese potato, this underwater rhizome can be as small as a small onion, which it in fact resembles, or as large as a coconut. Once cooked, it is like a slightly mealy potato. It needs to be peeled before using. This is the plant used to make arrowroot flour.

Batata: This dry-fleshed sweet potato is rounder than American sweet potato types and has a mottled red-purple skin. The batata’s name is taken from the species name for all sweet potatoes: Ipomea batatas. It is a favorite in Puerto Rican and other Latin American cuisines.

Boniato (Cuban sweet potato): A boniato is a white sweet potato similar to a batata. Boniatos can be found in Hispanic markets, especially in Cuban neighborhoods. They are now being grown in Florida.

Burdock: This root vegetable is brown-skinned, with white flesh that darkens quickly when cut. Popular in Japan, where it’s called gobo, burdock can be found in Asian grocery stores and some health food stores. It also grows wild in North America. The plant can be recognized by its very large leaves and spiny burrs, called cockleburs, known for sticking to your clothes when you walk through a meadow. Many people who eat burdock compare it to celery and artichoke, and consider the taste to be earthy and mildly sweet. Uncooked wild American burdock tastes very bitter, though cooking removes the bitterness. Burdock is good source of magnesium, potassium, and folate. It is also high in inulin, a sugar that can sometimes cause flatulence.

Cassava (also called Yuca or Manioc): This starchy tuber is cultivated in South America where it originated, as well as in Africa, the Caribbean, the South Pacific, and Florida. Cassava is shaped like an elongated potato. It’s about a foot long, weighs up to 3 pounds or so. Cassava is covered with a hairy, brown, bark-like skin enclosing soft, dense white flesh. Cooking it not only makes it palatable, but also eliminates a toxic substance that can form in varying amounts in the raw vegetable. Shop for cassava in Latin American markets. This tuber doesn’t keep well, but it may stay fresh for a few days in the refrigerator or in a cool, dry place. To prepare the vegetable, cut it into thick slabs and peel them one at a time with a sharp paring knife. Cassava can also be dried and ground into a flour called tapioca flour. Tapioca pudding is made from beads of tapioca flour.

Celeriac: Closely related to celery, this plant develops a knobby baseball-sized root with a crisp texture and intense celery flavor. Although not very popular in the United States, celeriac is a favorite vegetable in France and Italy, where it is eaten both raw and cooked. Cooked celeriac and potato complement one another, and the two vegetables are often combined in one dish. Like celery, this fall and winter vegetable can also be used as a flavoring and its stalks and leaves can be used to flavor soups and stews. Look for smallish, heavy, firm celeriac roots. If the stems and leaves are attached, they should be fresh and green. No matter how you’re cooking celeriac, it needs to be scrubbed well. Try celeriac in salads or as a crudité, with a creamy yogurt dressing or dip. Celeriac, like celery, is low in calories. Vitamin C and potassium are its key nutrients.

Crosne (Chinese artichoke): These look like little, beige-skinned spiraled seashells. They are similar to Jerusalem artichokes in taste and texture.

Cushcush: This is a species of tropical yam from the Caribbean with a variety of names: In Puerto Rico it’s called mapuey; in Cuba it’s an aja; in Jamaica it’s yampi.

Jerusalem artichoke (also called sunchoke): This tuber is native to America, and resembles a small nubby potato or a piece of ginger. Jerusalem artichoke has been its common name since the 17th century. But it is also sold under the name sunchoke, which is a more appropriate name because this plant has no connection to either Jerusalem or artichokes. Rather, it is a type of sunflower. Like potatoes and other tubers, the Jerusalem artichoke stores carbohydrates, but most of them are in the form of inulin, a sugar that can sometimes cause flatulence. The vegetable is also a source of iron, almost on a par with meat, yet without any fat content.

Jícama: Jícama is a white-fleshed tuber that can weigh from half a pound to 5 pounds or more. Shaped like a turnip, it has a thin brown skin and crisp, juicy flesh rather like a fine-textured apple. Its bland flavor enables jícama to be used in a variety of ways. You can serve raw slices or sticks sprinkled with lime juice and chili powder, or add it to salsa or salads. Include slivers in stir-fries—a good substitute for water chestnuts—or boil or bake jícama like a potato. Look for hard, unblemished jícama roots that are heavy for their size. Peel the papery skin with a paring knife. Store cut pieces of jícama in a container of cold water. Although jícama can be used in some of the same ways as a potato, it is less starchy and lower in calories. The vegetable is also a good source of vitamin C, and contains some potassium, iron, and calcium.

Kumara: Another tropical sweet potato, kumara is what the sweet potato is called in New Zealand. The traditional variety of sweet potato grown there is called the Owairaka Red, which is a direct descendant of an American sweet potato introduced to New Zealand in the 1850s by an American whaling ship. The kumara has red skin and white flesh.

Malanga: A starchy tropical tuber with a nutlike flavor, malanga, which is a Colombian word, is called yautia by Puerto Ricans. It is typically used as a bland foil for spicy side dishes or condiments. Sold in the Latin food section of some supermarkets and in Latin American grocery stores, malanga can be recognized by its yam-like shape—though it may weigh 2 pounds or more—and its rough, fuzzy brown skin, which reveals patches of yellowish or pinkish flesh beneath. Choose a firm, heavy root free of soft spots, and store it at cool room temperature for a day or two, or in the refrigerator crisper for up to a week. Peel malanga and boil, steam, or bake it until tender. Like potatoes, malanga can be served sliced, in chunks, or mashed, with a well-seasoned sauce or as a companion to a flavorful stew.

Name yam (tropical yam): The word name is the African word for yam. Name has a rough, dark skin and light-colored flesh. It is starchy and dry-fleshed and only slightly sweet. Use it as you would potatoes or sweet potatoes.

Parsley root: This beige-colored vegetable is a subspecies of parsley that is grown for its roots. It tastes somewhat like celeriac and can be used in a very similar fashion. The tops can be used like regular leaf parsley.

Salsify: “Oyster plant” is an old-fashioned name for this parsnip-like root vegetable, as some people find the flavor reminiscent of oysters. The long, 1-inch thick roots have tan skin and white flesh. Although it is not very common, you’ll find salsify in some markets in the fall and winter. Look for firm, plump, unblemished roots and store them in the refrigerator. After scraping or peeling the roots, place them in water with a bit of lemon juice to keep them from darkening. Like other root vegetables, salsify’s starch turns to sugar during cold storage. It is also sometimes left in the ground over the winter to sweeten, like parsnips. A single cup of cooked salsify has about 90 calories and provides riboflavin, vitamin B6, and potassium.

Taro: The word taro—as well as dasheen, malanga, and other names—is applied to quite a number of starchy tropical tubers, all which are high-carbohydrate foods that are staples in the Pacific islands, Asia, the Caribbean, Africa, and parts of South America. Taro root’s most familiar use is in poi, a sticky taro paste eaten in Hawaii. One of the more common forms of taro is a roughly cylindrical, brown-skinned root with white or pale purple flesh. You may find it in Spanish or Asian markets. Choose a firm taro root with no shriveled or soft spots. Store it in a cool, dry place or in the refrigerator crisper for no longer than one week. Taro resembles potatoes in flavor and uses. You can peel it before or after cooking. Boil, bake, or steam it, and serve it with a flavorful sauce. Be sure to serve taro hot—it becomes very sticky as it cools.

Water chestnuts: The crisp white flesh of a water chestnut has a mildly sweet flavor and a crunchy texture that is actually closer to apples than to any kind of nut. In their fresh form, they do look like chestnuts. But they aren’t nuts, and they contain almost no fat. The water chestnut grows underwater in mud. It has brown or black scale-like leaves and closely resembles a small, muddy tulip bulb. Since nearly all of the water chestnuts sold in the United States are canned, most people have only seen the water chestnut with its scaly outer covering removed. Although fresh water chestnuts need to be peeled and cleaned, it is well worth the effort. Fresh water chestnuts are tastier than canned ones, and when cooked they don’t lose their crunch. You can find fresh water chestnuts in Asian food markets. They should look sooty, but should be smooth, except for a few leaf scales. In addition, they should be rock hard and completely free of soft spots.

Yam: Americans use the term “yam” to mean orange-fleshed sweet potatoes. But in fact yams come from an entirely different and large, botanical group of vegetables of the genus Dioscorea. Not only is the yam family large—there are some 600 species—but individual members of the family have attained record-breaking weights. An African species called elephant’s foot produces a yam that can weigh up to 700 pounds! There are a handful of yams that eventually make it to the American market, by way of local African, Asian, or Caribbean populations: cushcush, name yam, Japanese yam, yama root, yamiamo. The names of these yams frequently translate simply as “yam.”

Yamiamo: This yam comes from Japan. It looks more like a severely elongated, cylindrical white potato than a yam. It has beige skin and white flesh, and it is fairly glutinous, with a texture similar to taro.