Cassava: From Toxic Tuber to Food Staple

By Christina Emery, Rachel Hirsch, and Melinda Susanto

When eaten raw, cassava is likely to leave a bitter taste in one’s mouth. Worse still, the unprocessed plant, containing high levels of cyanide, is poisonous to humans and can paralyze when eaten. Despite these deterring properties, cassava has long been culturally and nutritionally significant. And because Indigenous peoples of Meso- and South America discovered a way to render it edible through extensive processing, today cassava is enjoyed by 600 million people worldwide. One of the world’s major food crops alongside maize, rice, and wheat, cassava is cultivated as far away from its native habitat in South America as Southeast Asia. Nigeria is the world’s largest producer of cassava, where it is a primary source of carbohydrates for many and is consumed as part of a popular dish known as fufu.

How did cassava come to occupy this pride of place in the global food system? How did it transform from a poisonous tuber into a major food staple, and from an exclusive dweller of South America into a cosmopolitan citizen of the world? To answer these questions, this essay considers how human interactions with cassava helped to shape the plant into the significant food crop that it is today. We first look at the elaborate method of processing cassava developed by the Indigenous peoples of Meso- and South America and then turn to the codification and spread of this knowledge, facilitated by European travelers to the so-called New World. This meeting of Indigenous and European knowledge systems, combined with cassava’s tolerance for drought, resulted in a food crop that would create new hope for global food security in the twentieth and twenty-first centuries. Furthermore, as knowledge of cassava and its specimens circulated to different parts of the world, the plant took on additional cultural meanings through novel culinary uses and artistic representations.

Botanical drawing of cassava surrounded by caterpillars and other insects.
Drawing of cassava by Maria Sybilla Merian. Image Credit: Wellcome Collection

Of Frogs and Cassava: Early Cultivation in the Andes

Wild ancestors of the domesticated Manihot esculenta—known more commonly as cassava, manioc, or yuca—were likely introduced into Meso- and South-American agriculture by Indigenous farmers around 8000 BCE. Cassava was domesticated in these early agricultural plots, and the plant’s seeds and stem cuttings were traded over short distances.

Archaeological evidence suggests that cassava became an important food staple for several ancient cultures in present-day Peru, including the Chavin (1000–200 BCE), Nazca (200 BCE–600 CE), Moche (250–750 CE), and Chimú (1000–1470 CE).[1] 

Representations of cassava made by Moche artists provide clues as to how the plant was understood and appreciated by Andean peoples in the first millennium of the Common Era. Moche artists often represented cassava together with Leptodactylus pentadactylus—a frog found throughout the Amazon—as shown in this ceramic from Dumbarton Oaks’s collection. The smoky jungle frog, as this species is commonly called, was likely associated with agriculture, and representations of frogs may have been used in harvest-related rituals. Indeed, while cassava roots are the most commonly eaten part of the plant, they go bad quickly when dug up from the soil. However, if cassava is left in the ground, it can survive for up to four years and be harvested periodically.[2]

Indigenous Knowledge: How to Process Poison

While storing cassava in the soil addresses the issue of perishability, additional steps need to be taken to ensure that its roots can be safely eaten upon harvesting. In the Amazon, cassava is popularly divided into two major types—sweet and bitter—depending on the level of toxicity. Sweet cassava can be eaten simply by peeling and boiling it. Bitter cassava must be processed using a specific method before it can be safely consumed. The danger lies in cyanogenic glucosides, which vary in amount depending on the type of cassava, the climate, and the season in which it is cultivated. Women in Meso- and South America are primarily responsible for the processing of cassava and transforming the poisonous plant into flour for casaba, or cassava bread, and into a fermented beverage known as chicha. It is a multi-step process that includes washing and grating the cassava root, mashing it into a pulp, then hanging, dehydrating, and finally baking the dried pulp on a hot surface.[3]

1856 watercolor, “Saliva Indian Women Making Cassava Bread, Province of Casanare” by Manuel María Paz. Image Credit: Wikimedia Commons

Despite the amount of work required to process cassava with high levels of cyanide, bitter cassava is more popularly cultivated than sweet cassava in the Amazon today. The indigenous Tukanoans of the Yapu village in the northern Amazon, for example, grow 100 different types of cassava, 98 of which are bitter. Archaeologist Warren Wilson and anthropologist Darna Dufour have demonstrated that bitter cassava yields a higher harvest than does its sweet counterpart, possibly due to its resistance to disease and insects.  It is perhaps for this reason that bitter cassava is favored as a food crop over sweet cassava, despite the additional processing required to render it edible.

[1] Donald Ugent, Shelia Pozorski, and Thomas Pozorski, “Archaeological Manioc (Manihot) from Coastal Peru,” Economic Botany 40, no. 1 (1986): 99.

[2] Donna McClelland, “The Moche Botanical Frog,” Arqueología Iberoamericana 10 (2011): 40.

[3] Darna L. Dufour, “A Closer Look at the Nutritional Implications of Bitter Cassava Use,” in Indigenous Peoples and the Future of Amazonia: An Ecological Anthropology of an Endangered World, ed. Leslie E. Sponsel (Tucson: University of Arizona Press, 1995), 151.

The Power of Peony

By Ashley Buchanan

The Secret Ingredient

In 1735, a Viennese baroness wrote to the last Medici princess, Anna Maria Luisa de Medici (1669—1743), to thank her for sending a miraculous infant convulsion powder. Anna Maria Luisa’s recipe for infant convulsion powder contained a precipitation of a human skull (of “a man who died violently but was never buried”), a precipitation of “Oriental pearls,” a precipitation of red coral and white coral, as well as yellow amber and peony roots and seeds. While the more outrageous ingredients—the skull and Oriental pearls—stand out, it was actually the use of peony that made Anna Maria Luisa’s powder effective.

In her letter to Anna Maria Luisa, the baroness praised the powder’s effectiveness, stating that the children she treated with it had been so violently taken by convulsions that the attending physicians had “given up on them.” Not only had the “miraculous powder” cured the children, but they remained in perfect health several months later. Well known for her miraculous powder, Anna Maria Luisa strategically distributed it to influential individuals and courts across Europe. As a result, she created valuable socio-political alliances to protect The Grand Duchy of Tuscany as the end of the Medici dynasty neared.

Handwritten recipe in Italian.
Recipe for infant convulsion powder featuring peony. Image Credit: Archivio di Stato di Firenze (ASF), Miscellanea Medicea (MM) 1, ins. 2, fol. 186r. Photo by Ashley Buchanan.

The Popularity of Peonies

Peonies are not typically associated with medicine, since they have long been coveted for their beauty. In fact, peonies were first cultivated for their attractiveness and fragrance in China more than 1,400 years ago and became especially popular under the Tang Dynasty (618–907 CE). In the Tang imperial gardens, tree (or moutan) peonies reigned as the “king of flowers” and symbolized happiness, wealth, and prosperity. We can see the association of peonies with wealth and class in a rare Tang scroll painting that depicts five ladies of the court and one maidservant. The rank and prestige of each lady is shown by their scale relative to one another as well as by the lavish peonies that adorn their hair. As the popularity of peonies grew in China, so too did their varieties, as horticulturalists selected, hybridized, bred, and eventually grafted peonies for their fragrance, petal color, petal number, and size.

The center of imperial peony cultivation was in Luoyang, where there were peony festivals and competitions, gardens devoted solely to peonies, and even a peony research center. This led to a plethora of ornamental peony cultivars as peony breeding became an artform. More than 200 peony cultivars were described during the Song Dynasty (960–1279 CE); today, China has more than 1,000 cultivars.

Botanical painting of peony
Ming herbal (painting): Chinese herbaceous peony. Image Credit: Wellcome Collection

While peonies have a long history of appreciation and cultivation as ornamental garden plants in Chinese as well as Islamic gardens, in western Europe they mainly were valued for their utility. Over the course of the sixteenth century that changed, when Ottoman floriculture introduced numerous ornamental flowers to the gardens of Europe, including hyacinths, narcissi, peonies, and most famously, tulips. It was not until the end of the eighteenth century that Europeans would begin intensively breeding ornamental peonies.

In 1789, famed British naturalist Sir Joseph Banks acquired a “moutan peony tree” (Paeonia lactiflora) from Canton, China, through his connections with the British East India Company. Surviving the arduous journey to Britain, it was planted in the Royal Botanic Garden, Kew. Other peonies from China soon followed, ushering in something of a peony craze in Europe as, thanks to centuries of cultivation, Chinese peonies were larger, fuller, and more fragrant than native European varieties. Peonies became increasingly popular as French, English, and American horticulturists began developing ornamental varieties of their own from these exotic imported peony cultivars.

As a Chinese botanical export, eastern ornamental peonies, as well as the new herbaceous and tree hybrids created from them in Europe, carried connotations of the “exotic Orient” and became a popular subject in nineteenth-century art. The depiction of peonies in nineteenth-century French paintings, however, does more than simply signify the exotic or differentiate Occident and Orient. For example, in Frédéric Bazille’s Young Woman with Peonies (see below), the foreign provenance of ornamental peonies is emphasized by the Black model who arranges the blooms in an “Oriental” vase. Notably, Bazille pairs the peonies with irises, France’s national flower. Once new and exotic, ornamental peony cultivars had become a product of cultural hybridity, simultaneously signaling the plant’s eastern origin as well as the new varieties that were being developed in France.

Painting of young woman holding peonies, surrounding by other flowers
Frédéric Bazille, Young Woman with Peonies, 1870, NGA 61356. Image Credit: Wikimedia Commons

Today, peonies remain one of the most sought-after ornamental flowers in the world. Thanks to their abundant delicate petals, peonies often adorn gardens and homes, and are popular for wedding bouquets and floral arrangements. While peonies have long been, and continue to be, a coveted ornamental plant, what may surprise you is that they also have an equally long history—over two millennia—as a powerful medicinal therapeutic.

Cacao: Indigenous Network to Global Commodity

By Rebecca Friedel

A Coveted Tree 

Theobroma cacao is a coveted tree known as the source of the globally celebrated chocolate, initially known as xocolatl in Nahuatl. The fruits of cacao are a variety of berry known as drupes. Drupes grow from pollinated flowers on the tree’s trunks and lower branches, each containing between 20 and 40 pulp-covered seeds, colloquially known as beans. The beans were considered a valuable resource and commodity in precolonial times and hold a similar status today.

Originally domesticated in the tropical lowlands of South America, cacao quickly spread to Mesoamerica where it gained salient cultural status as far back as the Formative Period. This world-renowned plant also tells a story of shifting strategies of interaction and knowledge production during the early modern period. This era of imperial expansion saw a variety of European entities seeking to benefit from the economic goods and networks native to the Americas. Cacao was one of the most important of these networks, specifically the production, distribution, and consumption of its seeds.

The cacao tree is a delicate plant that needs specific conditions to grow and ultimately fruit. Knowledge of these conditions forms a body of deep cultural understanding of cacao’s cultivation, reflected in Indigenous ideologies and practices. European expansionism not only led to the distribution of cacao across the globe but also to the appropriation of the knowledge of Indigenous people. Primary sources from the early modern period document such dynamics between Native human and wild-grown plant populations of the Americas and the colonizers who sought to control them.

Early Recipes

Initial imperial strategies in the so-called New World allowed for the documentation of Native perspectives by Native individuals. The earliest representations of cacao from the early modern period come from a Mexica herbal known as the Badianus manuscript, a collection of elaborately watercolor-painted plants with their associated names in Nahuatl and recipes for treating various ailments written in Latin. This herbal was completed in the 1550s by at least two Nahua men, Martín de la Cruz, an Indigenous nobleman and physician, and Juan Badiano, an instructor of Latin, at the Franciscan school of the Colegio Santa Cruz in Tlatelolco. Now held by the National Institute of Anthropology and History in Mexico City, the manuscript has been reproduced in a number of ways since its original creation. Through its original and reproductions, the historically deep and broader Indigenous ideologies surrounding Theobroma cacao are captured.

Colorful herbal drawing of trees
Image of cacao and other plants from the Badianus Manuscript. Image credit: Wikimedia Commons

The herbal’s watercolors illustrate anatomically accurate plant structures situated within particular stages of the reproductive life cycle of cacao. These details indicate that the Mexica had an intimate understanding of cacao’s biology, a level of knowledge not found in contemporaneous herbals authored by non-Natives. Consequently, the knowledge of cacao within the Badianus has a broader spatio-temporal history, developing across Mesoamerica well before the arrival of Europeans and the formation of the school in which de la Cruz and Badiano created the herbal.

Ancient Ideologies

The association of cacao with curing particular ailments in Mexica recipes echoes what was known about the plant by Mesoamericans for thousands of years. In their cosmologies, the cacao plant is connected to maize, a staple crop throughout and beyond Mesoamerica that was highly mythologized. This connection of maize and cacao, typically conceptualized as a life cycle, is also exemplified by a broader ideology regarding a cycle of subsistence. The cycle includes a sequence of alternating a forest garden, where cacao is grown, with milpa, where maize is grown. This milpa/forest garden cycle is a subsistence strategy that was, and still is, central to providing sustenance to millions of neotropical inhabitants.

Etched Maya Bowl
Bowl with Anthropomorphic Cacao Trees from Early Classic Maya Period, 400-500. Image Courtesy: Dumbarton Oaks

Introduction to the Plant Humanities

By Julia Fine

Recipes, as the tagline of this project suggests, feature in many facets of daily life, from food to science, magic to medicine. At the basis of many (if not most) of these recipes are plants: we’ve learned here how chiles were used to treat malaria in early modern China, that cucumber juice contributed to a 17th-century Russian hangover remedy, and why coffee was understood as a potential cure for the Plague in Turkey.

Bright watercolor drawing of various plants, most likely from Malaysia or Sumatra.
Plate from [Album of Chinese Watercolors of Asian fruits], held by Dumbarton Oaks Museum and Library. The album was most likely produced by a Chinese artist located in Malaysia or Sumatra between 1798 and 1810. Image Credit: Dumbarton Oaks

Much of history focuses on decidedly human stories, where plants are relegated to the background. As historian Londa Schiebinger writes, “Plants seldom figure in the grand narratives of war, peace, or even everyday life in proportion to their importance to humans.”

We at Dumbarton Oaks Museum in Washington DC have spent the past four years working to rectify this by placing plants at the center of human stories as part of our Mellon-funded Plant Humanities Initiative. By bringing history together with botany, archaeology, art history, and other disciplines, we aim to highlight how plants have shaped the course of human history, and how humans have shaped plants in turn. The fruit of our exploration has been a digital humanities lab that puts narrative history side-by-side with primary sources, mapping tools, herbal specimens, and more in order to demonstrate the complexity of plants, as well as their importance in the current climate crisis.

Herbal specimen. Image Credit: Wikimedia Commons

Our lab now features over 15 original narratives on plants, with more coming in the near future. These plant-centered narratives are written by historians of science, art historians, paleoethnobotanists, geographers, and comparative literary scholars (among others). One narrative highlights how early modern women used herbs like dittany as a means to exert agency over their own health and fertility— a particularly critical topic given the vociferous debates about abortion occurring in the United States and elsewhere today. Another narrative on turmeric demonstrated how plants were not simply drivers of imperial expansion, but also tools through which understandings of the British Empire were spread.

Over the next month, we will be publishing excerpts from some narratives on The Recipes Project site. We will see how European conquistadors drew on Indigenous Mesoamerican recipes when transporting cacao to Europe. We will learn how peony, often imagined today as an ornamental flower, was used as a medicinal herb in both Chinese and Western medical traditions, where it was used to treat epilepsy, sciatica, and convulsions. And we will see how our modern-day fascination with cassava, frequently lauded as a “climate survivor crop,” would not be possible if not for the knowledge, expertise, and processing techniques developed by Mesoamerican and South American women, which allowed for poisonous cassava to be made edible.

Botanical drawing of a cacao vine
Botanical drawing of a cacao by Maria Sibylla Merian in her work Dissertatio de generatione et metamorphosibus insectorum Surinamensium , 2019. Image credit: Dumbarton Oaks

Together, these stories highlight the primacy of plants in the history—and future— of human society. We hope you enjoy your trip around the world through these narratives, and stay tuned for opportunities to get involved with our initiative.