Tepary Beans

Tumacacori highlands, north of the Arizona/Sonora border.

This landscape of thorny agaves, cacti, mesquite trees and rock is not the first place one might imagine searching for the future of food. How can such a hot, dry place contain some of the keys to nourishing the world?

We’re in the desert, an hour south of Tucson, in southern Arizona. Giant, natural walls of stone rise hundreds of feet above our heads to form a big horseshoe-shaped canyon appropriately named Rock Corral. The heat here can be punishing, and the rain scarce, and that was precisely the point. For the area is home to precious wild plants tolerant of such stresses, hiding in crevices and under scraggly trees providing just enough shelter for their survival.

This is one of a handful of places in the US where wild chile peppers grow. They’re the ancestors of the planet’s most important condiment, the spice that provides nutrients, flavor, and pain-induced endorphins to cultures worldwide. This “crop wild relative” – known around here as chiltepin (Capsicum annuum var. glabriusculum) – occurs from right here in Arizona, all the way south to Brazil. We notice prehistoric potsherds and grindstones at our feet. Archeological and linguistic evidence suggests human use of species as far back as 6000 years ago, in what is now Oaxaca and Puebla, Mexico, where the plant was probably domesticated.

The hodgepodge of land managers, agricultural scientists, conservationists, and educators visiting the canyon with us want to see the wild relative growing in its natural habitat. We head downhill to one of the main washes that drains the area. There, on alluvial shelves, hidden under thorny trees, we find wild chiles. Compared to their domesticated kin, the plants are small and scruffy, especially at this time of year. They have just a few leaves and pea-sized fruits, awaiting the return of the rains to start growing again.

Wild chiles remain important to local people, and some families have made foraging trips into this canyon to pick peppers for centuries. They are prized in these desert borderlands for their flavor, but more than anything for their heat. Families often keep a small mortar and pestle on the dinner table to grind a bit of fresh chiltepin to season their meals. On the other side of the border in Sonora, Mexico, foragers make a living collecting, sun-drying, and selling over 50 tons of the peppers a year. They sell for as much as $100 a pound.

While the plant is important in the region, what can it contribute to the future of food around the world?

The answer is resilience. The plants that call this canyon home—which also include the genetic relatives of sweet potatoes, cotton, grapes, tepary beans, and 50 other wild relatives—need nothing from humans to survive. They have to grow both when there is enough water and when droughts hit. Wild plants’ leaves angle to catch just enough sunlight without losing too much moisture; their flowers bloom at night to attract bats, birds, and moths that are active during the cooler hours; their seeds sprout just in time to meet the rains, then flower and fruit before the dry season.

These are signs of resilience that have mostly disappeared from domesticated food crops, which often need lots of water and nutrients, as well as protection from the elements, pests, and diseases. Re-introducing these traits into our food crops via plant breeding brings a much-needed “wildness” from crop relatives to their domesticated kin. But breeding can only happen if the wild species are still around to be able to offer their gifts.

The chiltepins and other crop wild relatives in the canyon are the fortunate ones. Their habitat has been actively protected for the last 20 years, thanks to the work of conservation groups like Native Seeds/SEARCH, the Arizona-Sonora Desert Museum, and the University of Arizona Southwest Center, who work directly with the US Forest Service. Collaborative efforts helped establish the 2,300-acre Wild Chile Botanical Area in the Colorado National Forest.

Unfortunately, most crop wild relatives are threatened by habitat loss due to urbanization, agricultural expansion, mining, and other land use changes, or by invasive species, pollution, over-harvesting, and climate change. Despite the challenges, the wild plants adapt to the changing climate, pests, and diseases. To be safeguarded and available for crop breeding, they likewise need to be collected and conserved in seed banks, botanical gardens, and other facilities where they will be available for research and education. The United Nations recognizes the importance of conserving crop wild relatives in Target 2.5 of its goal of Zero Hunger.

Among the most interesting crop wild relatives found in the Wild Chile Reserve is the tepary, whose cultivated cousin is among the most heat and drought tolerant crops in the world. As climate change exacerbates extreme heat and drought, teparies will likely become an increasingly important food resource, both culturally and nutritionally, for many indigenous groups in the region.

Because the tepary is such an important genetic and cultural resource, it makes sense that I find it at Native Seeds/SEARCH  a non-profit seed bank co-founded by Gary Paul Nabhan back in 1983, with a goal to preserve and safeguard seeds native to the Southwest. The collection now holds 90 different species (crop types) and 1900 different seed accessions (an accession is a specific seed collected at a specific place and time). The eight accessions of wild teparies come from San Pedro River Valley, Rock Corral Canyon, Sycamore Canyon, Santa Rita Mountains, Kitt Peak, and Santa Catalina Mountains; two of them also come from areas in Mexico: Tiburon Island (Sea of Cortez), and another from Chihuahua near the Sonoran border. They also have 78 accessions of domesticated teparies in the seed bank from all over Northern Mexico and the Southwestern US.

As Sheryl Joy, Collections Curator at Native Seeds/SEARCH explains, “One of the most special things about our conservation model is that we not only safeguard seed varieties in our seed bank, but also work constantly to make these seeds available to people to grow and use. Seeds are most valuable when people grow them, save them, cook them, eat them, and enjoy them. That is how seed conservation can be ensured— when people make them a regular part of their lives.”

The decision to grow out a seed is based on several factors, including popularity and utility of the seed, the length of time since the last growout, the longevity of the seed in cold storage, and the ability of NS/Sto work with a diverse growers who are excited to grow the crops in their communities.

Because many seeds in their collection are important to the indigenous groups that stewarded them for generations, NS/S makes the seeds freely available to those communities from which the seed was collected. Though economic and social pressures have made it difficult for many of these communities to maintain their traditional foodways, seeds remain important to their cultural identity as well as their health. Another special facet of NS/S’s collection is that seeds are adapted to the hot, arid conditions of the southwest. As climate change brings desert-like conditions to more regions, crop wild relative seeds’ special adaptations will become more and more important.

The University of Arizona’s Desert Laboratory, a 115-year-old research institute on Tumamoc Hill – an 860-acre reserve on the edge of downtown Tucson, was established to understand how native local plants survive—or even thrive— tough environments. What was perhaps not as well recognized back then was how much of the native flora provided critical sustenance to people, nor how diverse and interesting were the local wild relatives of humanity’s food crops.

Recent studies are showing that Arizona is among the US states with the richest range of culturally and economically valuable wild plants. Native species from dozens of plant genera have already been used to improve resilience to climatic stresses, enhance resistance to pests and diseases, improve nutritional quality, and offer hardier rootstock for fruit, nut, and berry crops. Moreover, dozens of native wild plants continue to provide nutrition and cultural value directly to locals. In total, over 1,000 wild species grow across Arizona, half of which are either close relatives of domesticated crops or valuable food sources in their own right. Of these, around 150 are ancestors or close cousins of globally-important crops.

With all this in mind, our diverse group had come together to facilitate effective work between seed banks, botanic gardens, wild lands managers, academics, conservation organizations, and educators to ensure the survival and continued availability of desert plants.

The good news is that more than half of the crop wild relative species found in two nearby reserves – Rock Corral and Walnut Gulch – are already safeguarded in Arizona’s seed banks, nurseries and botanical garden collections. The bad news is that much work remains to be done to ensure that other important crop wild relatives and edible desert plants are conserved.

Tucson is the first UNESCO designated city of gastronomy in the US, and both Tucson and the Rock Corral Wild Chile Reserve are part of the new Santa Cruz Valley Natural Heritage Area. These designations were given because Tucson has become a model for desert cities around the world: they’re safeguarding and restoring both wild and cultivated food plant diversity, with over two thousand varieties freely shared through their free seed library network.

Talking about a food revolution without food at the table isn’t how things are done in the desert borderlands. James Beard award-winning chef Janos Wilder of Tucson’s Downtown Kitchen provides us with the opportunity to sample a number of different dishes featuring wild plants and desert-adapted crops native to the region and other parts of North America – including a range of crop wild relatives. These included a tepary bean spread with za’atar (a blend of locally harvested wild thyme, sumac, and sesame seeds), cholla (cactus) flower buds in a cold bean salad, wild tomatillos, wild oregano, and wild rice. And, of course, the chiltepin. There are also a range of beverages fermented from wild sotol and agaves. It wasn’t difficult to convince the crowd that these wild plants were not only useful for resilience, but also tasty.

To find and purchase tepary beans, look no further than Ramona Farms, a Native American (Akimel O’Odham) farm and business based in Sacaton, Arizona, which has been growing heirloom crops like the tepary bean (white, brown and black) for over forty years.

By the end of this voyage, our group created a stronger resolve to work together to protect these hardy plants and to make sure they are available to contribute to a more resilient food future. The climate is likely to get hotter, drier, and more erratic across most of the borderlands in the years to come. Scarce moisture will become only more precious. Local food production will be even more vulnerable to the heat and drought. It’s a very real possibility that the remaining water will go to domestic uses rather than agriculture, making locals even more dependent on importing food from greener states in the U.S. and Mexico. One thing we can all agree on is that every bit of progress we can make towards being able to grow crops adapted to hotter and drier conditions will be worth it – efforts can contribute to more stable yields, lower costs for farmers, and more overall regional food security.

In recent years, collaborative initiatives have shown that it is possible to reach beyond institutional silos to catch the wild plants falling between the cracks in organizational mandates.

With the burn of fresh chile still on their lips, this group has identified five priority areas for partnership to conserve and increase awareness about the importance of crop wild relatives:

1. Further understand and document our crop wild relatives and wild utilized plants, assess threats to their natural habitats, and determine gaps in their conservation.
2. Better protect important and threatened species in their natural habitats.
3. Collect and conserve the diversity of prioritized species in public genebanks, botanic gardens, and other conservation repositories.
4. Make this diversity more accessible and attractive for plant breeding, research, and education.
5. Raise public awareness of their value and the threats to their persistence.

Tepary beans are annual legumes. Wild forms still exist in North America and grow as twining or weakly trailing intermediate vines that climb shrubs or trees. The domesticated varieties are bushier and grow up to one foot tall and 20 inches in diameter. The leaves are trifoliate and have narrow, pointed leaflets. The flowers vary from white to light colored. The fruits grow in small pods, from 1.25 to 3 inches long, and contain 2 to 7 seeds. Domesticated beans are ⅓ of an inch long and can vary in color from brown to beige to black to white, whereas wild seeds are smaller, dark, and mottled. Tepary bean roots are associated with nitrogen fixing bacteria (USDA).

There are two major types of tepary beans: white tepary beans and brown tepary beans. The two varieties have similar uses, but white tepary beans are sweeter than the more earthy tepary beans. Although tepary beans can be ground into meal, like most common beans, they are most prepared as a whole, dried shell (USDA). Drying the beans is beneficial because it increases shelf life. Prior to cooking the beans, they should be soaked (preferably overnight) as soaking greatly decreases cooking time. To prepare the beans, boil them for several hours or until tender (Ramona Farms). Once cooked, the beans can be used in salads, stews, chilis, and other classic bean dishes. However, it must be noted that tepary beans are toxic when raw, so it is crucial to ensure the beans are tender before consuming them (NUS).

Tepary beans are a more nutritious alternative to more common beans, like pinto and navy beans. They are high in protein and dietary fiber, nutrients which combat diabetes (Native Seeds). Further, tepary beans contain lysine, an essential amino acid that aids in protein development and lowers cholesterol. Tepary beans are also iron-rich, and have the potential to combat widespread iron deficiency – up to 30% of the world is iron deficient (Bhardwaj and Hamama). High levels of unsaturated fats in legumes like tepary beans also reduce the risk of colon and breast cancer and cardiovascular disease (Jiri and Mafongoya).

Traditionally, tepary beans are grown at the start of the heavy rain season (mid-June to mid-July). They can be grown using modern irrigation techniques, but excessive irrigation or rainfall will lead to poor establishment and can cause more vegetative growth rather than high seed production. Soil tests should be done before planting to know if any nutrient amendments are necessary, but nitrogen fertilizers should be limited so as to not inhibit root nodulation and nitrogen fixation. The first harvest can be from 60-120 days after planting. The beans can be harvested by hand or mechanically. Tepary bean is at risk of common bean diseases like common mosaic virus (USDA).

Tepary beans originated in North America and have been cultivated for thousands of years. Although their archeological record does not show their first domestication’s exact location, one record discovered domesticated tepary beans in the Tehuacán Valley, Mexico dating back approximately 2500 years. In Arizona, the beans were found in Hohokam sites dating back around 1000 years. The Tohono O’odham tribe in the Sonoran Desert of Arizona has one of the strongest cultural ties to tepary bean cultivation. One of the group’s myths teaches that white tepary beans were scattered across the sky to form the Milky Way. Teparies were widely grown in the Tohono O’odham Nation until World War II, when many farmers joined the military or began working on large-scale cotton farms. The Tohono O’odham people are now working to incorporate the tepary bean, among other traditional foods, back into their diet including in school lunches (USDA).

After recognizing tepary beans’ capacity to fight malnutrition and food insecurity, Bioversity International launched a series of surveys in Guatemala with hopes of integrating tepary beans into the common bean value chain. Stakeholders, like manufacturers and distributors, in Guatemala’s bean value chain showed interest in tepary beans. Further, food industry actors stated that they were willing to undergo trials to determine whether value added tepary bean products can meet industry quality and nutritional standards (Bioversity International). Existing research affirms tepary beans’ nutritional profile and high resistance to drought, but in order to determine if tepary beans can serve as an alternative to common beans, additional, locally-driven research must be conducted.