New Orleans, Louisiana - This Friday, May 22, marks the International Day for Biological Diversity. Every year, the United Nations uses this day as an opportunity both to celebrate the Earth’s stunning biodiversity and to recognize our task to protect it.

Unfortunately, due to biodiversity loss from industrialization and unsustainable land use, the planet’s health is threatened. Nearly a quarter of wild food species—plant and animal—are decreasing in abundance, according to the U.N. Food and Agriculture Organization. Biodiversity is not only important for the planet—but it’s important for human health, too. Eating a range of fresh fruits, vegetables, and whole grains can help immune systems by providing the full range of nutrients, from vitamins C and D to zinc and iron. And COVID-19 is revealing the urgency of improving immunity—and the power of food to protect us. 

“There’s a range of vitamins, of flavanols, of minerals that have been looked at, that we know improve the immune system function. … Several specific nutrients seem to have activity against COVID-19-specific proteins,” Dr. Dariush Mozaffarian, a cardiologist and the dean of the Tufts University Friedman School of Nutrition Science and Policy, told me on Food Talk Live this week. “What’s really interesting, beyond the general immune-boosting effects and the COVID-specific protein effects, many of these same nutrients or other nutrients blunt or soften this excessive inflammatory response that’s really what’s causing deaths in COVID.”

These 15 indigenous crops, among countless others, are prized in traditional agriculture systems for their resiliency, diversity, versatility, and most of all, nutritious value.

1. Amaranth (huauhtli, Amaranthus)

The more than 75 species of amaranth grow across nearly every continent, from the humid lowlands of Africa to mountainous countries in South America. Amaranth, which grows quickly in hot weather, is cultivated both as a leafy green and a cereal-like grain which can be ground into a flour or eaten whole. Many indigenous communities including the Aztecs and southwestern North American tribes have been growing amaranth since it was first domesticated in 6000 BCE. The Aztecs particularly favored amaranth for both culinary and ritualistic purposes. During the Aztec festival, Panquetzaliztli amaranth flour was used to create figurines of the deity Huitzilopochtli. These figurines were then used during processionals and then distributed throughout the community. The use of amaranth became almost nonexistent with the Spanish colonization, however, it is still used today for its nutrient-rich grain. It’s an excellent source of protein, vitamins, and essential minerals, including calcium, iron, magnesium, potassium, and zinc. 

2. Arracacha (batata baroa, apio, Arracacia xanthorrhiza)

An important South American root crop, Arracacha is best described as somewhere between a carrot and celery root. It was originally cultivated in the Andes, but because of its versatility and low-input costs, is now an important crop in many lower regions of Brazil, Colombia, and Venezuela along with Cuba and Puerto Rico to the north. The arracacha root has been a staple in diets across South America, particularly within the Andes region. Arracacha is typically prepared similarly to potatoes but contains four times the calcium as potatoes and significant carotenoid pigments, the precursor to vitamin A. It also is rich in iron and vitamin C.

3. Bay of Fundy Dulse (wadakuna’sikjech, Palmaria palmata)

Dulse is a red seaweed that’s been used for culinary and medicinal purposes across Ireland, Iceland, and Canada’s Atlantic coast. It has been an important food source for the people of the First Nations Mi’kmag. Dulse that grows in the Bay of Fundy, between the provinces of New Brunswick and Nova Scotia, was once a popular snack food and an important ingredient in traditional chowders and stews. It has a high protein content, and contains iodine, iron, and many other trace vitamins and minerals.

4. Chaya (Cnidoscolus aconitifolius)

Chaya, an evergreen plant native to the Yucatán Peninsula of Mexico, has been a staple of indigenous diets for centuries in Mexico and Central America. Chaya grows very easily and is resistant to insects, heavy rains, and droughts. The leaves must be cooked to be safe to eat, but chaya is rich in protein, vitamins A and C, calcium, iron, phosphorus, and many minerals and enzymes and it has been used in Maya medicine to treat ailments including diabetes, insomnia, high cholesterol, and indigestion. Additionally, families in rural communities prepare chaya tortillas for special occasions and some religious holidays.

5. Chayote (chayotl, Sechium edule)

The chayote, derived from the Aztec word chayotl, is a green, pear-shaped member of the squash family that has been an important part of diets across mesoamerica since pre-Columbian times. The Ancient Aztec and Mayans, who still grow this squash, traditionally cultivated the plant for consumption and medicinal purposes. The plant is extremely versatile and can be grown in warm climates from sea level to more than 2000 meters above sea level. Most parts of the plant may be eaten, including the fruit, stems, and leaves, and it’s a good source of vitamin C and folate.

6. Desert Lime (cumquat, Citrus glauca) 

Desert lime grows naturally in the semi-arid regions in eastern Australia in a range of soil types and has  traditionally been collected in the wild by indigenous peoples in Australia. It is tolerant of heat, frost, drought, and salinity, and it can withstand extreme temperature conditions from -12 degrees C to 45 degrees C (10.4 degrees F to 113 degrees F). It has been used for generations to make cordials, sauces and chutneys and has high levels of vitamin C, folate, calcium, and antioxidants. 

7. Fonio (findi, fundi, Digitaria)

The two species of fonio — white and black — grown across West Africa are versatile and gluten-free varieties of millet. Fonio is fast-growing and suitable for dry conditions, although very labor-intensive to harvest. The grain has been cited as a path toward greater food security in Africa and is high in iron, calcium, and several essential amino acids. Fonio is highly valued in the Sahel culture of West Africa. In addition to serving as a source of vital nutrition, fonio has been used as dowry gifts and as an offering in traditional spiritual ceremonies.

8. Kakadu Plum (gubinge, man-djiribbij, mu-jiburrbarlmuna, Terminalia ferdinandiana)

The kakadu plum—also called the gubinge, billygoat plum, or murunga—grows across northern Australia and has the highest recorded natural vitamin C content of any plant in the world. The aboriginal people in Australia traditionally ate the fruit and seeds raw and roasted the sap to heal skin conditions or use it as a tea for colds and flus. Aboriginal groups in Northern Australian continue to grow the plant for its medicinal and nutritious purposes. Suited to its natural hot and coastal environment, the kakadu plum can grow in a variety of dry and saline habitats, from dry creek beds to cliff tops and ridges.

9. Kumara/Sweet Potato (Ipomoea batatas)

Sweet potatoes, also known as kumara in many Polynesian languages and in New Zealand’s indigenous Māori language, are a staple crop across Africa, Asia, and many cultures within and surrounding the Pacific Ocean. The starchy vegetable is a great source of protein, vitamins A and C, iron, calcium, and dietary fiber. It has also been shown to have anticoagulant properties.

10. Målselvnepe Turnip (Brassica rapa subsp. rapa)

This old Norwegian landrace of turnip has been improved over the years through selective cultivation and it is one of only a few landrace varieties still grown today. Originally known as the Ol’Enok-turnip, it is believed that the seed was imported through the pomor trade between the Pomors of Northwest Russia and the people along the coast of northern Norway. It has an excellent, yet strong and distinct, taste compared to other turnip varieties. It can be eaten raw, roasted, baked, and boiled, and is frequently used to enhance the flavor of soups, salads, stir-fries, and side dishes. The Målselvnepe turnip is an excellent source of vitamin C and potassium.

11. Mung Bean (maash, moong, Vigna radiata)

The mung bean – maash in Persian or moong in Sanskrit – is thought to be indigenous to India and may have been domesticated several times in Persia (Iran), Pakistan, and India. It is important in diets across Asia and valuable for its easily digestible protein. High levels of iron in the vegetable help improve the diets of the most vulnerable women and children, and mung bean production offers an opportunity for increased income for small-scale farmers. The vegetable can also fix nitrogen in the soil, making it valuable for crop rotations.

12. Northern Wild Rice (manoomin, Zizania palustris)

Northern wild rice, one of four global wild rice species, grows across the Great Lakes region in the U.S. and in aquatic areas of Canada’s Boreal Forest. Wild rice has been central to indigenous foodways in the region, particularly among the Chippewa (Ojibwa) tribes in Minnesota, for millennia. Although it is now domesticated and cultivated largely for commercial sale, much of it is still harvested using traditional methods. Wild rice is rich in vitamins, minerals, antioxidants, and fiber, and contains more protein than most other whole grains.

13. Pawpaw (assimin, umbi, Asimina triloba)

The pawpaw fruit is the largest edible fruit indigenous to North America. It was central to Algonquian, and Choctaw diets, who call the fruit assimin or umbi respectively, as well as Siouan, Osage, Iroquois, and other peoples native to eastern North America. The pawpaw has a tropical flavor reminiscent of a mix between mangoes and bananas. It was grown and eaten by Native Americans and early European settlers, although it has proven difficult to commercialize due to its very short shelf life after harvesting. However, the fruit is high in vitamin C, magnesium, and iron, and also contains some vitamin A. The bark of the pawpaw tree was traditionally used to make ropes and string for catching fish and the seeds of the crop have been used as a powder to prevent head lice.

14. Purslane (Portulaca oleracea)

Since prehistoric times, purslane has been grown by humans around the world, from Australia to the Middle East to Asia. It’s still common in Mediterranean dishes and is used among aboriginal communities, including the Wadjari, Wanman, Pitjandjara, Ngadadjara, Iliaura, and Wakaja peoples. Purslane is capable of CAM photosynthesis in extreme conditions, which allows the plant to grow while saving water, making it a very successful plant across many climates. Purslane also contains more essential omega-3 fatty acids than any other leafy green, and the plant is also extraordinarily high in vitamin E. The crop has been used to treat a variety of maladies including burns, headache, intestinal diseases, and arthritis.

15. Tepary Beans (stoa bawi, to:ta Bawi, Phaseolus acutifolius)

Tepary beans have been a staple crop for thousands of years and have been culturally important to the Tohono O’odham and Pima peoples in the American southwest. Today, they remain important for indigenous farmers across North America. They grow quickly in arid desert conditions and are resistant to alkaline soils, making them one of the most drought- and heat-tolerant crops in the world. Although related to standard beans, tepary beans actually contain more protein, calcium, fiber, iron, and zinc, and have a low glycemic index. Because of their high fiber levels, tepary beans help to prevent a rapid rise in blood sugar levels after meals, which helps keep those with diabetes healthy.