Lost crops where the buffalo roam

One of the great unsolved mysteries about the origins of agriculture is why people chose to spend so much time and energy cultivating plants with little tiny unappetizing seeds in a world full of juicy fruits, savory nuts, and plump roots. Many anthropologists believe that that only explanation is desperation: either human populations grew too large to live on better foods, or environmental conditions rapidly changed and caused declines in plants and animals that humans preferred to eat. In either scenario, people turned to collecting the seeds of annual grasses and herbs because of scarcity, not because they were attractive foods.


My colleague Paul Patton collecting seed from scattered populations of goosefoot, a lost North American seed crop, in Ohio, 2017. Photo: NG Mueller

Anthropologists in this school of thought point out that collecting small seeds from scattered plants or fragmented populations is time consuming with low caloric returns compared to, for example, collecting nuts or tubers (edible roots). Worse, the costs in time and labor of eating small seeds do not end with the harvest: small seeds need to be threshed, winnowed, and, in most cases, cracked, ground, or sprouted in order to be turned into food that humans can digest. This is because most are encased in layers of tough, indigestible tissue that protects the food contained in the seed itself.

seed cleaning

Before (left) and after (right) cleaning goosefoot seeds. In my experiments, this process takes about 3 times as long as harvesting. Photos: NG Mueller

Another weird thing about agriculture is that many of the species people eventually domesticated would have been very difficult to cultivate in their wild form. This is because, again, of all those seed protections. Seed and fruit coats prevent moisture from reaching the seed and delay germination. If you collect the seeds of wild crop ancestors and then try to plant them the next spring without any kind of seed treatment, most will not germinate. How did ancient people overcome this barrier? We know they eventually went from simply collecting seeds from naturally occurring stands of wild plants to clearing fields and planting seeds. But why would they bother if the seeds they planted never germinated?


Germination of wild-type seeds with robust seed protections (left), and of domesticated-type seeds with weaker protections (right) after the same treatment. These seeds came from the lost crop erect knotweed, which was domesticated by ancient Indigenous communities in eastern North America.

I’m hoping to find the answer to both of these questions in … bison dung. A pile of dung might seem like a strange place to look for answers about the origins of agriculture, but bear with me.  I recently published a paper with my colleague, Rob Spengler, arguing that grazing animals like bison may have played an important role in the domestication of many of our crops. Here’s the story.


Part I: Plants hitch a ride.

During the Ice Age, glacial advances and retreats created big problems for plant populations: they had to find ways to rapidly move across the landscape or go extinct, particularly in the vast mid-latitude grasslands of North America and Eurasia. Many plant species survived by hitching a ride in the gut of an animal. An animal would be attracted by the tasty and nutritious fruit of the plant, but the seeds inside the fruit would pass through their digestive tract and be deposited in a new area in a package of nitrogen rich poop – win, win! Plants that formed this kind of relationship with grazing animals in particular had a unique scheme: since these animals prefer to eat leaves over fruits, these plants have evolved to present their seeds as the centerpiece of a bouquet of tasty leaves. But since many leaf-eating grazers have particularly gnarly digestive systems that have evolved to break down tough, fibrous foods, these plants also have evolved particularly small and hard seeds, which can pass through this digestive gauntlet in good enough shape to germinate on the other side. Another unusual characteristic of such plants is that their seeds will not immediately fall off when they are ripe, as do seeds that are dispersed by wind or water. These seeds have instead evolved to hitch a ride: they are waiting among the leaves to be eaten.


Seed bouquets of sumpweed (left) and goosefoot (right), two plants that were domesticated by ancient Indigenous communities in eastern North America, fall 2018. Photo: NG Mueller.

Part II: Humans arrive on the scene.

Imagine you find yourself in the midst of vast grassland on foot and hungry. While this landscape may seem less threatening than, say, a dark forest, it is just as disorienting and difficult to move through. How will you walk through the tall grass without being bitten by snakes, falling into burrows, or becoming hopelessly lost? How will you find water? These problems can be solved if you manage to pick up another animal’s trail.

exclusion vs trace

Tallgrass prairie in late spring with no bison trail to follow (left), versus following a bison trail from stream to stream (right). Photos: NG Mueller

Now you can walk quickly and with less fear. You are sure to come to a source of water before too long, because other animals need to drink, too. Maybe you’ll even have an opportunity to hunt the animals you are following. As you follow the trail, you come to a place where the animals have recently been. Their trampling, wallowing, and grazing has created a large opening in the grassland on the banks of a river where they stopped to drink and sleep. Within this clearing, instead of tough perennial grasses, you find dense stands of lush annual plants. These stands have the appearance of a garden, because they are growing in enriched soil with relatively little competition.  They are covered in edible seeds just waiting to be harvested. You know you’ll have to do some work to make these little seeds palatable and nutritious, but such a dense concentration of easily harvested food is irresistible.


My colleague Ashley Glenn, harvesting dense stands of crop wild ancestors growing in a wallow on the tallgrass prairie, late spring 2019. Photo: NG Mueller

Part III: Plants find new partners.

If we fast forward 1000 years from this hypothetical first encounter, we might find a community of people who has made this patch of grassland their home. In some places, such as Eurasia, North Africa, and highland South America, they have formed such a tight connection with grazing animals that they no longer stalk them as game. The animals have become domesticated cows, goats, sheep, llamas, and alpacas. They are allowed to graze freely, but are penned at night or during certain times of year. The plants they disperse grow around people’s houses and in their corrals, and are also eaten by people. In other places, like eastern North America, the bison herds are still wild, but the plants who’s seeds they disperse have become familiar during years of following game trails and building camps and villages in the clearings they create.

In either case, people collect the edible seeds of these plants for food rather than letting the animals eat them all. They save some of the seed and plant new fields, which they thin and weed to give each plant more nutrients and sun to produce seeds for them. Over many generations (which for these plants are just a single year), the plants respond to new selective pressures created by humans. Freed from the need to survive an arduous passage through the gut of a ruminant, their seeds can be larger and have less hard coats and still survive – actually, these attributes are advantageous in their new environment, because people favor seedlings that emerge and grow rapidly by thinning out smaller seedlings from their fields and gardens. This process leads to the evolution of many domesticated crops like quinoa, amaranth, millet, sorghum, buckwheat, and the lost crops that I study.

havrest 2

My mentor and colleague Gayle Fritz conducting controlled harvest of sumpweed in a bison wallow, fall 2019. These populations strongly resemble those I have raised in gardens, but they are denser so the plants are smaller. Ancient farmers may have thinned such populations, a selective pressure that would have favored the evolution of bigger seeds that germinate more rapidly. Photo: NG Mueller

There is quite a bit of circumstantial evidence that this really is what happened in many different times and places, but the various hypotheses embedded in the story need to be tested. Taking just the North American case as an example, some of the questions I’ve been trying to answer in my field work this year are:

Is it really easier to move through a grassland on bison trails? If you follow these trails, do you find populations of wild crop relatives? Do they form dense stands that are easy to harvest? Are the bison dispersing the seeds of these plants?

Before I started this project, I already knew the answer to this last question was “yes,” from a previous study conducted on the Joseph H. Williams Tallgrass Prairie Preserve, a Nature Conservancy project near Pawhuska, Oklahoma. Claudia Rosas and her colleagues collected 144 dung samples over the course of an entire year on the prairie, and documented two of the lost crops (little barley and sumpweed) in dung. They also collected fur from bison during the annual fall roundup, and documented the same two species (along with many others) in these samples. This is remarkable, since little barley sets seed in May and June. These plants were hitching a ride on a bison’s back all summer! Wallows are formed partly by bison rolling around on the ground, so there is a high potential for these furry animals to both pick up and drop off seeds in these prime locations. Lucky seeds who wallow-hop with bison will find themselves germinating in nitrogen-enriched, well-watered clearings, and ideal place to be a baby plant.


Bison fur in a wallow full of little barley. Photo: NG Mueller

In our study, we want to see not only if these plants are consumed by bison, but also if their seeds can germinate after the long and treacherous journey through a bison’s gut. We duplicated Rosas’ methods, but instead of collecting all year we are just focusing on the times when we know the lost crops are setting seed: late May-early June and October. We collect fresh dung then wash it and dry it (yes, you can wash dung!) In the lab, we sub-sample the dung, taking half of it to the greenhouse to see what emerges from it and the other half to the microscope for seed identification.  We are also experimenting with other seed treatments. Some seeds need a long period of ripening in hot weather before they will germinate, and others need to experience cold, wet conditions as a trigger. There are a lot of variables to explore, but luckily there is no shortage of bison dung!


Plants that have germinated from our spring dung collections so far. Photo NG Mueller

In our study, we are also taking a more controlled, experimental approach. In collaboration with Cliff Montgomery, a Missouri bison rancher, we will be feeding batches of crop progenitor seeds to a bison, then collecting all of his dung systematically. This will allow us to see what percentage of seeds make it through, and what effect this has on germination rates.

captive bison

Bison romping at Cliff Montgomery’s ranch. We will be feeding crop wild ancestor seeds to one of these fellows in early December in the final part of our project. Photo: NG Mueller

This has been very exciting research that has added an important new angle to my understanding of the plants I study. I’ve been cultivating them for years, but before this year I never had a clear idea of how they were first encountered by foragers and why they looked attractive to these highly knowledgeable ancient people. Now that I’ve seen them growing along bison trails and in wallows, I think I understand why people were inspired to start a momentous relationship.

Another transformative moment for my understanding of the lost crops came this fall came when I shared a meal made from my harvests with a wonderful group of friends and colleagues during the Anthropocene River Journey. To my knowledge, this was the first time anyone had enjoyed these plants as food in over five centuries. Many thanks to Lynn Peemoeller and Chef Rob Connoley for making this dream a reality.

anthropocene event

Chef Rob Connoley serving dishes made from lost crop seeds at the Granite City Arts District as part of the Anthropocene River Journey’s St. Louis visit (left), and (right) one of the chef’s creations, featuring erect knotweed seed crackers and squash mousse. Thanks to Haus der Kulteren der Welt and the Max Planck Institute’s Anthropocene Curriculum Project, for funding this research and for facilitating the Edible Narrative, at which we awakened a culinary tradition that has been sleeping for centuries.


How genomics and gene editing are about to turn ancient garbage into a hot commodity

For thousands of years, humans have been trying to understand the diversity of life on earth. Many of our systems of classification are based on bodies (phenotypes or morphologies). For example, as a paleoethnobotanist, I study tiny fragments of ancient plants that were left behind by people at archaeological sites – mostly in the garbage. I use the shape and size of ancient seeds to discover which species they came from, and then to describe variation in populations, especially of crop plants. The bodies of ancient organisms can tell us a lot about the origins and evolution of biodiversity. Whole fields are based on this premise: paleontologists study fossils; bioarchaeologists, paleoethnobotanists and zooarchaeologists study ancient remains of humans, plants, and animals recovered from archaeological sites. Up until recently, extinct forms were scientifically priceless, but held no economic value for agriculture or medicine. De-extinction was a topic for science fiction.

Though usually remembered for its depiction of dino de-extinction, Dr. Ellie Sattler’s reaction to this leaf (“Alan, this species has been extinct since the Cretaceous”) at the beginning of Jurassic Park’s most iconic scene implies that the thinking-machine-super-computer had also managed to ressurect lost plant species. Sadly, this never comes up again in any of the many Jurassic Park films. 

But we’re currently witnessing a revolution in the study of ancient biodiversity: genomics has cannonballed into archaeology and made an epic splash. With this methodological sea change, we have an opportunity to address fundamental questions that were unanswerable with older methods, but we also face new ethical questions. Much ink has already been spilled announcing the arrival of the genomics revolution in the study of ancient human DNA. There has been an explosion of research in the past decade, enabled by next-generation sequencing and breakthroughs in methods for separating out damaged fragments of ancient DNA from modern contaminants. Since we humans are naturally quite interested in ourselves, it is not surprising that these new techniques have been applied earlier and more widely to the study of human evolution than to that of plants and animals. Already, ancient genomic approaches have been used to better understand the sex lives of ancient humans, Neanderthals, and Denisovans (spoiler alert: they were all having sex with each other, and it was adaptive!), to test old hypotheses about the demographic effects of Neolithic Revolution, and to understand the evolution of specific human adaptations, such as the ability to digest lactase in adulthood and low hemoglobin levels in high altitude populations.

From Slatkin and Racimo, 2016, this figure shows the rapid increase in recovery of ancient human genomes between 2010 and 2016. In the past two years, this trend has continued and intensified.

These studies are revolutionizing how we understand human evolution and history, but they have also spawned very serious problems. Renowned human geneticist David Reich recently caused a snafu with an editorial in the New York Times conflating populations (in the biological sense of the word) with races and arguing that it is “no longer possible to ignore average genetic differences among “races.”” (Click here for more on this controversy). Meanwhile, white supremacists are chugging milk to demonstrate their European ancestry, in an homage to one of the studies cited above. Researchers have also raised concerns about the (sometimes) wanton destruction of ancient human remains for aDNA extraction, and how irreplaceable and rare specimens are being hoarded by a few elite institutions. These concerns are about to become major problems in the study of ancient plant DNA, too, because…

Screenshot of white supremicists chugging milk at a protest in New York City, as reported by Amy Harmon.

A revolution is also underway in biotechnology. Maybe you’ve heard about CRISPR/Cas9 and thought “That’s just too much acronym for me to process today,” but please bear with me. This discovery is already transforming our world – and especially our food. Previous methods of genetic modification involved infiltrating or blasting cell nuclei with packages of modified genes and hoping they incorporated properly (1,2). Because the new genes incorporated more or less randomly into the target organism’s genome, biotechnologists had to rely on a brute force evaluation of thousands of modified plants or animals to identify a few in which the new genes had been properly incorporated, yielding the desired new trait. Making multiple targeted changes using these methods was extremely labor and time intensive. CRISPR/Cas9, on the other hand, is a gene editing tool that allows modified or novel genes to be inserted into the target genome at precisely the right place.

Schematic of CRISPR/Cas9 system, courtesy of Wikimedia Commons.

This method makes use of two defense mechanisms that bacteria use to fight off viruses. CRISPR (clustered regularly interspaced short palindromic repeats, in case you were wondering) is a piece of RNA created by bacteria to help them recognize viruses that they have previously encountered.  After recognizing a virus, bacteria deploy Cas9, an enzyme that destroys the virus by cutting apart its genome (you’ll sometimes hear Cas9 referred to as “molecular scissors.” (Read more here!) Biotechnologists can now use modified CRISPR RNA to target specific places in the genome of the organism they are modifying, and Cas9 to insert the new gene at that place. This method is a game changer because it makes genetic modification much more precise and predictable. In the US, we have already seen our agricultural system transformed by genetically modified crops created using much clunkier methods. Not only is CRISPR/Cas9 gene editing an extremely efficient method, the USDA has officially declined to regulate CRISPR/Cas9-edited crops by reframing this technology as a “plant breeding innovation.” There are already five CRISPR-edited products being developed for the market, including soybeans, camelina, lawn grass, maize, and mushrooms.

From Walz 2018, reused with permission from Springer.

What do these two scientific breakthroughs – ancient genomics and CRISPR/Cas9 gene editing – have to do with ancient garbage? That’s the million-dollar question.

This year, two reviews appeared, one in Nature: Plants, and the other in Frontiers in Plant Science, both arguing that ancient plant remains have just become a source of valuable information for the biotech and crop breeding industries. Their argument is based on two points:

  1. We are suddenly able to recover millennia worth of lost agrobiodiversity from around the world.
  2. We have simultaneously developed the tools to directly incorporate useful variation from ancient plants into modern crops.

The conventional view of the evolution of agrobiodiveristy. After Allaby et al. 2018, Fig 1.

To start with the first point, why would ag industries care about the variation contained in ancient crop genomes?  Well, first take a gander at my schematic of the “conventional view” of the relationship between genetic diversity and domestication. In this view, there is a steep drop in diversity, called the domestication bottleneck, when a small subset of a large wild population is brought under cultivation. For most crops, this happened thousands of years ago. From there, development of different varieties led to increasing biodiversity within the crop population. We call the results of this diversification landraces, which are regionally specific crop varieties, often adapted to local tastes or environmental conditions.  When crops were taken into new regions this could have led to more bottlenecks, especially if dispersal was followed by isolation. Then diversification would have begun again in multiple regions, and sometimes these distinct populations came back together through trade and migration, leading to a huge amount of agrobiodiversity worldwide.

Wheat landraces collected in Turkey. Image by Alexei Morgounov/CIMMYT.

Finally, we have a known bottleneck in agrobiodiversity that started with plantation economies and colonialism and culminated in the industrialization of agriculture during the 20th century. During this process, seed selection and crop breeding moved off of farms and most landraces fell out of cultivation, although many are still preserved in seed banks and herbaria. Today, the overwhelming majority of seed planted globally comes from crop breeders or biotech companies. They only produce a relatively limited number of “elite” varieties that have usually been bred for yield. Pant breeders and biotechnologists have always known that landraces and the wild progenitors of crops are diversity high points, and sources of useful genetic variation for crop improvement. They can use the relative diversity of these populations to breed or engineer useful traits into commercial varieties – things like drought and virus resistance, particular tastes, or different nutritional properties.

But recent insights from ancient crop genomes have called the assumptions of the conventional model of crop evolution into question. Ancient genomic data for three crops (maize, barley, and sorghum) seems to indicate that there was no domestication bottleneck. Instead of a sharp drop in diversity immediately after domestication, these crops experienced a gradual loss in genetic diversity over the course of thousands of years. One important implication of this research is that the genomes of ancient crops may hold useful traits that were lost long before colonizing botanists started to fill seed banks with landraces. In other words, the amazing variety of crops that were grown around the world when the Age of Exploration began may not actually be a high point in diversity. The high point may instead have come thousands of years ago, and there is likely a unique evolutionary history for every crop.

This would all be academic if it weren’t for simultaneous breakthroughs in gene editing. You can’t (usually) get ancient seeds to germinate, so however much valuable diversity these lost varieties hold, they would have been useless to modern plant breeders before genetic modification. But now, using gene editing, it is possible to reverse engineer living crops to replicate desirable aspects of ancient varieties.

My favorite lost crop: ~2,500 year old dessicated erect knotweed fruit from Cold Oak rockshelter, KY. Image by Natalie G. Mueller

How you feel right now is probably largely determined by your opinions about genetically modified crops in general. Personally, I find the idea of de-extincting lost crops using gene editing, frankly AWESOME. But I know enough about the history of GM crops to guess that research along these lines will not be driven by my desire to have a historically accurate garden.  Instead, ancient genomes will be mined for profitable traits, and what was once the cultural heritage of particular communities will become extremely valuable private property through the alchemy of formal breeding and genetic modification. The archaeobotanical collections that could make this kind of research possible are extremely rare, fragile, and difficult to recover. They are a limited and non-renewable resource. Curators, archaeologists, and descendent communities should get started now developing ethical and legal frameworks to guide the use of archaeobotanical specimens, before the application of ancient genomic studies expands to plant breeding and biotechnology.


Allaby, R. G., Ware, R. L., & Kistler, L. A re-evaluation of the domestication bottleneck from archaeogenomic evidence. Evolutionary Applications, 0(0). doi:doi:10.1111/eva.12680

Di Donato, A., Filippone, E., Ercolano, M. R., & Frusciante, L. (2018). Genome Sequencing of Ancient Plant Remains: Findings, Uses and Potential Applications for the Study and Improvement of Modern Crops. Frontiers in plant science, 9(441). doi:10.3389/fpls.2018.00441

Estrada, O., Breen, J., Richards, S. M., & Cooper, A. (2018). Ancient plant DNA in the genomic era. Nature plants, 4(7), 394-396. doi:10.1038/s41477-018-0187-9

Ficiciyan, A., Loos, J., Sievers-Glotzbach, S., & Tscharntke, T. (2018). More than Yield: Ecosystem Services of Traditional versus Modern Crop Varieties Revisited (Vol. 10).

Haak, W., Lazaridis, I., Patterson, N., Rohland, N., Mallick, S., Llamas, B., . . . Reich, D. (2015). Massive migration from the steppe was a source for Indo-European languages in Europe. Nature, 522, 207. doi:10.1038/nature14317


Huerta-Sánchez, E., Jin, X., Asan, Bianba, Z., Peter, B. M., Vinckenbosch, N., . . . Nielsen, R. (2014). Altitude adaptation in Tibetans caused by introgression of Denisovan-like DNA. Nature, 512, 194. doi:10.1038/nature13408


Itan, Y., Powell, A., Beaumont, M. A., Burger, J., & Thomas, M. G. (2009). The origins of lactase persistence in Europe. PLoS computational biology, 5(8), e1000491.

Jaganathan, D., Ramasamy, K., Sellamuthu, G., Jayabalan, S., & Venkataraman, G. (2018). CRISPR for Crop Improvement: An Update Review. Frontiers in plant science, 9, 985-985. doi:10.3389/fpls.2018.00985

Kuhlwilm, M., Gronau, I., Hubisz, M. J., de Filippo, C., Prado-Martinez, J., Kircher, M., . . . Castellano, S. (2016). Ancient gene flow from early modern humans into Eastern Neanderthals. Nature, 530, 429. doi:10.1038/nature16544


Llamas, B., Willerslev, E., & Orlando, L. (2017). Human evolution: a tale from ancient genomes. Philosophical Transactions of the Royal Society B: Biological Sciences, 372(1713). doi:10.1098/rstb.2015.0484

Makarewicz, C., Marom, N., & Bar-Oz, G. (2017). Ensure equal access to ancient DNA. Nature, 548, 158. doi:10.1038/548158a

Prendergast, M. E., & Sawchuk, E. (2018). Boots on the ground in Africa’s ancient DNA ‘revolution’: archaeological perspectives on ethics and best practices. Antiquity, 92(363), 803-815. doi:10.15184/aqy.2018.70

Racimo, F., Sankararaman, S., Nielsen, R., & Huerta-Sánchez, E. (2015). Evidence for archaic adaptive introgression in humans. Nature Reviews Genetics, 16, 359. doi:10.1038/nrg3936


Seguin-Orlando, A., Korneliussen, T. S., Sikora, M., Malaspinas, A.-S., Manica, A., Moltke, I., . . . Willerslev, E. (2014). Genomic structure in Europeans dating back at least 36,200 years. Science, 346(6213), 1113-1118. doi:10.1126/science.aaa0114

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Harvest time!

The summer has flown by! Yesterday we harvested our first batch of lost crops. We’ve been getting A LOT of rain this week, so my research assistant, Andrea White, and I took advantage of the beautiful sunny day yesterday to harvest three replications of our goosefoot experiment.

Each replication is divided into four quadrants so that we can study the effects of different plant densities on yield and biomass. One quadrant of each replication has all three fall maturing lost crops growing in it (that is, sumpweed, erect knotweed, and goosefoot — click here to get caught up on the lost crops). We think it is unlikely that these plants were grown as monocrops by ancient people, since descendant communities are renowned for their innovative polycultures. We’ll soon have data about how these species do as a community vs. on their own, which Andrea will be analyzing for her independent study this semester.


Sumpweed and goosefoot growing together and getting along just fine.

Andrea and I harvested the senesced goosefoot plants by uprooting them, then hand stripping their seeds. We’re using big funnels, paper bags, and a tarp, but if ancient people used this technique they probably used tightly woven baskets, bags, and mats like the ones that have been found in rockshelters in Arkansas. I decided to harvest the plants this way to minimize seed loss, and so that I could also measure the weight of the stripped plants as a compliment to our plant density data. We can now say how density effects plants size, and how both of these measurements interact with yield. Even though these are small plots, I am hoping this will help us reconstruct what ancient fields might have looked like.

edens bluff bag fritz and smith 1988

An ancient bag full of domesticated goosefoot seeds from Eden’s Bluff, Arkansas. Image from Fritz and Smith 1988.

We also timed ourselves to see how labor intensive the harvest would have been. This is one way that archaeologists have characterized the efficiency if growing lost crops in the past. Although the harvest is certainly an important job, Andrea and I agreed that it was much easier and more pleasant than the hours (cumulatively, days) of weeding we did in the spring and summer. Harvesting was actually relaxing.  We enjoyed the perfect weather, bopped to some tunes, and felt a keen satisfaction from the pitter-patter of seeds raining into our bags. Looking forward to another break in the rain to get back out there!


Plasticity and domestication

Yesterday I had a chance to share my research at the Cornell School of Plant Science Horticulture Seminar. This is the first time that I’ve spoken about how I became interested in plant plasticity —  the way and degree to which plants react to their environment. In the context of domestication, you can think of plasticity as the way plants behave when they meet humans. Some animals are easier to tame and bring into the family than others, and I think some plants were predisposed to join human society, too. My current project at Cornell is investigating how developmental plasticity may have played a role in the process of domestication.

Several years ago, when I was working on describing the lost crop erect knotweed, I found its changeability frustrating. Documenting what it looked like was like grasping at sand — there was no typical form. Gradually, I came to see this plant’s responsiveness to its environment as the subject of my research, rather than a barrier.

If you’ve never heard of lost crops, this talk is also a good way to introduce yourself!

Growing lost crops: It has begun!

The only reason I started writing this blog post 2 days ago, instead of  continuing to furiously tend my lost crops, is because it was pouring rain. When it started raining, I was where I have been nearly every daylight hour for the past three weeks: in my field (or “patch,” as my father calls it). I was weeding an experimental plot of maygrass. Undeterred, I kept weeding for another 2 hours, until the mud was sticking to my fingers and I could no longer pull weeds with the precision necessary to avoid pulling lost crops, which are also weeds. I said a silent but sincere Thank you to the Earth for finally watering my babies, then packed it in for the day.


My Dad, Tim Mueller, weeding one of the goosefoot plots after some much needed rain. It’s surprisingly difficult to weed when you’re cultivating…weeds.

Average precipitation for June in Ithaca, New York, is 3.85 inches –we have received only 2 inches this month. It shouldn’t be necessary to irrigate weeds, especially in a place as wet as central New York, but I needed to keep the seed beds damp to encourage as much germination as possible. When I got home from a conference on June 14th and found the parched, clayey soil actually cracking, I made an emergency trip to Tractor Supply (one of many) for hoses and a sprinkler. Not the most high-tech irrigation solution, but pretty much all the tap near my field can handle– and works in a pinch. The best time to be out in the field moving a sprinkler around is just before sunset on these long summer days. I can bring my dog and book, or puzzle over small oddities in my plants in peace.

The saga of getting these plants to germinate began back in December, when I started experiments to see what kind treatment the seeds of each species needed make them sprout. Domesticated plants have been selected and bred by people for thousands of years to germinate as soon as they are planted. The thing about wild seeds is that they have never been able to count on humans to collect and store them in safe places, then plant them somewhere that they will like the next year. Instead, they have evolved diverse means of protecting themselves from freezing, flooding, drought, getting chewed on and digested by animals– and then, when conditions are just right, “knowing” that it is time to germinate.

Over the course of the winter, my research assistants and I developed some pretty good guidelines for treating the seeds of each species. Although we weren’t getting the 80% germination that you can expect from most store-bought seeds, we were getting at least 25% and sometimes as high as 70% with our most successful treatments, and we applied those treatments to the seed stock for the main experiments I had planned for this summer. Between May 2nd and May 18th, we planted everything in experimental plots and started the vigil for sprouts.

Even after months of preparation, I was far from confident that all five species would grow. Those germination experiments were conducted in the greenhouse. The greenhouse might as well be a different planet when it comes to experimental results. On Planet Greenhouse, every day is 12 hours long. It’s always 80 degrees during the day and 65 degrees at night. Planet Greenhouse is made of homogenous, rich, loose, potting soil, which is always perfectly moist, but not too wet. There are almost no bugs, and no larger animals to chomp on tender seedlings. It’s a wonderful planet for baby plants, but not at all like Planet Earth.

After 8 weeks of weeding and watering and watching, we have now counted over 5,000 seedlings representing all five lost crops in three different experiments. Some are behaving a little strangely, but that’s to be expected given that I’ve taken them out of their habitats and life cycles.


Some of the freshly weeded and watered plots, full of thousands of seedlings at last — I had a lot of help and moral support from my Dad (background) this week. 

For example, consider the two lost crops that are spring maturing grasses, maygrass and little barley. In the wild, they germinate either in late fall or in very early spring, and by June they have already produced all their seed for the year and died. I couldn’t plant them in early spring here at Cornell, because there were several feet of snow on my field in March. That’s normal western New York stuff, but by mid-April things were getting a little upsetting. I had to push back the preparation of my field for weeks, until after the last snow, which occurred as I was laying out experimental plots in mittens and boots on April 30.


Laying out the field on May 1. There was snow the day before.

That’s one of the many downsides of leaving Planet Greenhouse for Planet Earth: weather. I decided to make lemonade from crappy spring lemons and look into something that my colleagues and I have been wondering about: Would it have been possible for ancient people to get two crops per year out of these species? If you plant seeds after the first harvest in May, could you get another crop in late summer?

I planted maygrass and little barley in May, and they are just starting to flower now. The jury is still out, but its looking good for two-crop lost crops! The maygrass is doing something odd. Instead of growing to ~40 cm before flowering, some of my seedlings are producing flowers when they are only 4 cm tall. If they can muster the energy to produce seeds with so few leaves, this is not necessarily a bad trait from a farmer’s perspective: more seeds in less space and time. It is also interesting to see how the maygrass and little barley interact. We’ve gotten the best germination and the earliest flowers in the plots where the two species are grown together.


Maygrass and little barley germinating together at the beginning of June.

Other experiments have not been as successful. Out of thousands of seeds sown, I’ve counted only 12 sumpweed seedlings. I spent four entire work days weeding empty sumpweed plots, hoping they would germinate if I kept them clear and moist, but so far no luck. The dry weather this June is probably worse for sumpweed than for the other species, since this plant grows in marshy locations (its other common name is marsh elder). We are still hoping for some late comers, but even if they never sprout we’ve learned something valuable about sumpweed – how not to grow it.


My research assistants, Peter and Andrea, transplanting knotweed last week. This was the last experiment we set up, and the only one that relied on plants started in the greenhouse.


As of yesterday, everything is finally laid out, built, planted, and weeded (for now…), and this week we can concentrate on collecting data for the first time. It’s been the busiest two months of my entire life, but it’s wonderful to see all of these plants growing together and I am looking forward to learning from them everyday for months to come.


This final experiment we set up is comparing knotweed responses to sun and shade — but more on that next time!

Lost crops and living knowledge profiled by CBC’s Quirks and Quarks

I spoke with CBC’s Quirks and Quarks on Sunday about my research on eastern North America’s lost crops. Listen here!

I was pleased that Quirks and Quarks chose to pair my interview with the fascinating and vital work of Kim Recalma-Clutesi (Ogwiloqwa) to preserve and apply traditional ecological knowledge in her community. “Lost things found!” are always fascinating (they’re the bread and butter of archaeology), but they are only a tiny part of the story of Indigenous North American ethnobotany.  I can’t emphasize enough how important Native American crops still are to food security and cuisines all over the world. Even more importantly, there are Indigenous communities all across North America who are advocating for the right to tend and care for the plants and animals in their homelands. Community knowledge based on thousands of years of experience is more important now than ever, as we face population growth and climate change. I wish every story about lost crops could appear beside a story about ecological knowledge that is preserved, passed on, and applied.

‘Life finds a way’ in the ruins

Precarity is that here and now in which pasts may not lead to futures. – A.L. Tsing


River cane. You can tell it apart from bamboo, which it otherwise resembles, by it’s smaller maximum stem diameter (if you see plants with greater than 3 inch stems, probably bamboo) and this little sulcus (groove) on the stem above the node. If you find it, keep it safe!

Anna Tsing’s 2015 book “The Mushroom at the End of the World: On the Possibility of Life in the Capitalist Ruins” explores how places that are seen as ecological travesties, such as lodgepole pine plantations in Oregon, have become habitat for a species with enormous economic value: the matsutake mushroom. This mushroom underpins an informal economy that, among other things, provides an escape from wage labor to Southeast Asian refugees and American Vietnam vets alike.  Looking deeper back in time, the matsutake has always been associated with early-growth forests and human disturbance. In Japan, where this ‘weedy’ mushroom is most valuable and meaningful, urbanization and conservation have reduced the extent of this kind of heavily disturbed forest habitat. Now Japanese demand is met by pickers in America’s plantation forests.

Last Thursday, I was driving through a section of the Big Creek Wildlife Management Area in central Arkansas with my friend Liz Horton. I was trying to find places where the dirt roads crossed creeks and rivers, because these are the best places to look for the plant species I am studying. On our first attempt to penetrate this publicly owned space, which ostensibly exists to provide habitat for wildlife and hunting and fishing for the citizens of Arkansas, we immediately encountered a metal gate plastered with disconcerting signs. “Biocontainment area,” they cryptically warned. “Keep gate closed and locked” – although it stood open. Proceeding cautiously onward, we found ourselves in the middle of fracking station. There are hundreds of these stations on publicly owned land in north-central Arkansas. They have been accused of everything from illegally injecting diesel fuel into the ground water to increasing the incidence of earthquakes (in nearby Oklahoma).

fracking station

Photo of fracking station in timber plantation, Arkansas, that I surreptitiously took while creeping by at 2 miles per hour.

This experience echoed my exploration, weeks of earlier, of Wayne National Forest in Appalachian Ohio, where fracking and conventional oil drilling operations are leasing large parts of federally owned conservation areas, transforming these spaces from a refuge for the people, plants, and animals who live there to a liability and health hazard. These are only the latest in hundreds of years of irresponsible, but entirely legal, extractive industries in this forest, beginning with clear cutting by Euroamerican settlers, which eliminated all of the old growth forests in the eastern United States except for a few tiny pockets. In the Wayne, we saw rivers running red with old mining effluent. Acid seeps out of old coal piles and abandoned mines, eliminating all aquatic life in many streams. Both of these “natural areas” are surrounded by poor communities who bear disproportionate health and environmental costs.


Monday Creek

Monday Creek in Wayne National Forest runs red from old mining effluent


Conventional oil well in Wayne, near the Ohio River. I saw dozens of these over the course of two days, some surrounded by splatters of oil and dead plants, others inhabiting seemingly healthy clearings.

But sometimes in the most ravaged places, I find the rare native plants I am looking for, as when we found a population of marsh elder growing in an old pit mine. In these places, the presence of lost crops provides a glimmering of the deep history of this land and its entanglement with people – a reminder of another way of inhabiting this landscape that was based on enhancement rather than extraction. These plants survive where they do because of their ancient affinity with people, what you might call weediness, and despite an array of institutions that are indifferent to their annihilation. It is  important to keep in mind that although some fragments of native plant and animal communities remain, the Indigenous communities who tended and carefully managed these ecosystems for thousands of years were long ago forced off of the lands that I study, which are now being somewhat less thoughtfully managed by the US government and various industries.


Maygrass growing alongside GM herbicide tolerant maize field, Arkansas, 2015.

In May of 2015, my colleagues and I found an enormous stand of maygrass, another lost crop, growing alongside a corn field in southeastern Arkansas. This weedy margin was probably saved by the fact that it was growing right alongside a “ditch” – an old bayou that has been canalized by the building of levees – and was separated from the corn field by a dirt road. This small separation was key. We could tell by looking at the eerie cleanliness of the corn field that it was glyphosate resistant maize (like almost 90% of the maize grown in the US), a genetically modified crop that can withstand being sprayed with herbicide (“Round up ready”). We’d been looking for maygrass on field margins devoid of any living plants for three days before we found this remnant. The advent of GM herbicide resistant crops has spelled doom for ecosystems of weedy annual plants that once thrived in agricultural landscapes.


Shrinking margins in GM herbicide tolerant soy fields, Mississippi, 2015.

The situation for rural wild flowers and weeds was already bad two years ago, but it just took a turn for the apocalyptic. During the twenty years since the release of glyphosate tolerant crops, glyphosate has killed many weeds – but not all. The survivors have rapidly evolved the same herbicide tolerance that was engineered into the crops. One plant in particular has come to plague farmers: palmer amaranth. Maybe you’ve heard of amaranth – it’s a common weed (sometimes called pigweed) with edible leaves best enjoyed as a vegetable in the spring. It’s also a grain crop in Mexico and the US southwest, and one of the lost crops of eastern North America – it was grown as a crop in Arkansas for at least 600 years by Indigenous people. But now, after 20 years of GM crops and wanton glyphosate spraying, it has a new role to play as a superweed. It is impossible to kill and extremely invasive. I don’t think I was out of sight of a palmer amaranth plant the entire time I was in the state of Arkansas. So in 2016, Monsanto and BASF rolled out a solution: a new generation of herbicide tolerant cotton and soy that were designed to work with a new herbicide called dicamba – a chemical savior that could slay the superweeds.


Blow torching palmer amaranth in Minnesota, 2016

This summer, the use of the new genetically modified crops increased dramatically, and so did dicamba spraying. This strategy did kill some superweeds – but it also led to millions of acres of damaged crops and untold damage to wild ecosystems, which were already surviving at the margins. The problem is that dicamba is much more volatile than glyphosate. It floats up off of the dirt and drifts around when it’s hot and humid (probably didn’t help that 2017 was the 2nd hottest year on record). So farmers who made the switch had a great year – their neighbors who didn’t plant dicamba resistant crops were not so lucky. If this situation continues, cotton and soy farmers will have no choice but to adopt the new tech, meanwhile farmers who grow other crops for which dicamba resistant seeds are not available (not to mention anyone who still cares about wild plants) have no choice but the suffer the consequences of yet another irresponsible, destructive industrial method for extracting profit.


Soybean with dicamba drift damage. Photo: Univerity of Arkansas Cooperative Extension Service

Last Friday, as I was driving back north towards Missouri, a curious piece of news broke. Monsanto announced that it is suing the Arkansas State Plant Board, which is trying to stop this egregious state of affairs by prohibiting dicamba use in hot weather.  Yes. You read the right. Millions of acres of crops were damaged by their new product and they’re suing Arkansas for trying to put limits on its future use.

Anyway. Back in Big Creek WMA, we backtracked quickly and quietly out of the fracking station and tried another route. We soon found ourselves driving through a vast timber plantation. This homogenous pine forest is created by plowing deep furrows and machine planting identical pine seedlings at regular intervals. When the trees reach a prescribed age, the area is clear cut, any remaining undergrowth is burned, and the process begins again. Much like other forms of industrial agriculture, this creates an extremely simplified ecosystem whose purpose is to maximize growth of a single commodity species. Among other problems, clear cutting leads to erosion of hillsides, which can clog streams and cause more severe and destructive flooding.


Flood debris

timber clear cut

Clear cut area

In a pocket of valley too steep for industrial tree-farming, we stumbled upon something Liz had been trying to show me for years: a big stand of native river cane. Cane brakes used to cover vast swaths of the river valleys of eastern North America. It was extremely important to the livelihoods of Indigenous communities, who used it for baskets, combs, gaming pieces, drills, pipes, arrow and dart shafts, blowguns, tattoo needles, and more. It is still needed for some of these uses, especially to make beautiful cane baskets, by Indigenous Southeasterners, but it is in increasingly short supply.

River cane is now considered critically endangered, which made finding it on the margin of this industrial landscape all the more jarring. While I tend to focus on food (in my research as well as my personal life), I think Liz is quite correct when she insists that fiber crops were just as important to ancient people as food crops. Among these, river cane was undoubtedly one of the most important, but little is known about how it was managed and tended. Its once-abundance lives on in dozens of cane-related place names across the southeast and Midwest.

liz and cane

Dr. Liz Horton, happy to have found one of her favorite plants.

cane plural

Stand of cane. The creek valley in the background is full of recent run-off from the industrial timber farm upstream.

I’m not sure how to conclude these observations. I don’t know what surprises me more: the unheeding destructiveness of many of the rural industries I encountered, or the fact that anything other than commodity crops manages to survive among them. I suppose it is as Hollywood chaotician- Jeff Goldbaum said, “Life finds a way.”

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