As a species, we have a remarkable tendency to look at almost any living thing and only see another version of ourselves. Even plants are not safe from our projections. We divvy them up into heroes and villains—native and invasive species. This paradigm is botanically incoherent, if not altogether misleading. It says a lot more about us, and the nativist roots of our society, than it does about the natural world.

Consider the story of kudzu. A beautiful perennial vine with large, luxurious leaves, this member of the pea family is a hero in Japan. It grows innocuously throughout the country, where it has proven useful for its versatility; it can be weaved into baskets, ground into food, and boiled to produce a range of traditional medicines.

In the United States, meanwhile, kudzu is a villain. With nicknames like “the vine that ate the South,” “mile-a-minute plant,” and “foot-a-night vine,” it is known as the invasive species par excellence. Countless news articles have portrayed it as a foreign bioweapon, slowly taking over landscapes and choking out native specimens. Kudzu is prolific, no doubt. Anyone who has driven through the American southeast has seen its leaves twine around trees, telephone poles, and houses. But there is another story to be told here.

When kudzu made its American debut in 1896, at the first World’s Fair in the United States, it drew “oohs” and “aahs” from the millions of visitors. The vine seemed to have countless desirable traits. It could be grown in almost any soil and could endure any weather, from heat waves to cold snaps to droughts. As a legume, it had nitrogen-fixing bacteria, which made it an ideal candidate to prevent erosion. In the 1930s and ’40s, the Civilian Conservation Corps enlisted hundreds of volunteers to cultivate kudzu across the American South, offering farmers $8 an acre to plant the stuff.

Soon, the vine was thriving from Texas to Georgia. In fact, it grew much better than it ever had in Japan. This is the story of many so-called “invasive” species. Invited to a new part of the world for their desirable properties, they thrive with an unexpected vigor, only to be recast as invaders.

In my research as both a plant biologist and a scholar of gender and sexuality studies, I have found a striking convergence in our vocabularies across plant, animal, and human worlds. Our botanical authorities habitually describe invasive plants as hyper-fertile and prone to aggressive, uncontrollable expansion, echoing the stereotype of the hyper-fertile third world immigrant. They warn about foreign plants cross-fertilizing with native species to produce alien hybrids, a callback to fears of miscegenation. One article summarizes this outlook succinctly: “They Came, They Bred, They Conquered.”

Donna Haraway, the prominent scholar of science and technology, has argued that this kind of conceptual cross-pollination is innate to the way we make sense of the world. Haraway encourages us to understand societies as “naturecultures”—a framework that recognizes the intimate entanglements of humans with our environments. This may help us understand why xenophobic outbreaks are so often accompanied by fears of foreign plants and animals, as well as new anxieties about hygiene and disease. Seen through this prism, the burgeoning field of “invasion biology” starts to appear in a strange new light.

The Garden Path

The emergence of invasion biology (IB) is most often credited to Charles Elton and his influential 1958 book The Ecology of Invasions by Animals and Plants, though it didn’t fully take off as a field until the 1980s. IB has since expanded steadily, thanks to a constant stream of donor and media attention, and its devotees now straddle the worlds of academia, policy, and environmental activism. The National Science Foundation (NSF) has created committees and grants to study biological invasions; governments at all levels have implemented policies against invasive species; environmental groups such as the Nature Conservancy, Sierra Club, and Greenpeace have all developed programs to repel them.

The field is predicated on a binary view of nature, as in place and out of place—native and invasive. IB proposes geography as a singular criterion for desirability. The concept of nativeness is a recent invention. Many scholars have pointed to how widely definitions of “native” can vary, rendering it a scientifically incoherent category. Nevertheless, the field of invasion biology soldiers on. In tandem with fluctuating racial anxieties, it contributes to a general sense that the native world as we know it is quickly disappearing. Nature and culture are both increasingly seen as out of place.

The historical linkage between these anxieties is a matter of record. Historian Nancy Tomes, for example, has documented how periods of heavy immigration to the United States have coincided with a heightened fear of germs. And these fears of disease naturally extend to exotic plants and animals. On the flip side, a desire for natural purity often manifests in curated and controlled plant experiences. In Nazi Germany, as garden historians Joachim Wolschke-Bulmahn and Gert Groening demonstrated, the “natural gardening movement” arose to help guard against alien influences—a nativist push by other means.

Notions of purity and impurity have a way of transcending species. In both cases, products of the “global” are perceived as threats to local ways of life. The profound irony is that the descendants of former colonizers are the ones most worried about being colonized. Nativism, it turns out, is a product of many inventions.

A Long View

Invasion biology suffers—or one might say, benefits—from amnesia. Once one takes the long arc of history into account, a completely different story of plants and animals emerges. Eurasia and the Americas were once part of a single supercontinent in the landmass of Pangaea, until about two hundred million years ago, when it fractured and floated into new continental formations. Species were separated and traveled into novel environments, leading to a dizzying diversity of adaptations. Then, in a flash of planetary time, as environmental historian Alfred Crosby argued in a landmark study in the 1970s, colonialism reknit the “seams of Pangaea.”

As colonists conquered new lands, they imposed new regimes of life. They moved species around the world, willy-nilly. Since 1492, the world has grown more alike as its ecosystems have collided and intermingled in a “biological bedlam.” Bananas and coffee, two African crops, are now the principal agricultural exports of Central America; we would not have the cuisines of modern Thailand, Italy, or India without peppers and tomatoes from Mesoamerica. What Crosby termed the “the Columbian exchange” transformed the ecology of the planet. Colonialism was nothing if not a bioinvasion.

Our theories of nature often neglect how these colonial interventions reshaped the biogeography of non-human entities around the world. Where humans went, plants, animals, fungi, bacteria, and viruses followed. This is why environmental historians have argued that we should understand imperialism as fundamentally an ecological project.

As Crosby powerfully chronicled, European settlers created “Neo-Europes” wherever they went. Where these experiments thrived, indigenous ecosystems suffered. This legacy is now sewn into the soil. There is, as a recent ecological study showed, a remarkable similarity of flora between regions occupied by the same empires. As the authors argue, “we find that European colonial history is still detectable in alien floras worldwide.”

As I show in my book Ghost Stories for Darwin, colonial rule and colonial settler experiments were marked by a laissez faire—indeed, competitive—attitude towards plant migration. In the late nineteenth and early twentieth centuries, the USDA instructed a team of biologists to roam the globe as “explorers” in search of new and interesting plants of economic and aesthetic interest. Dr. David Fairchild, director of USDA’s Section of Seed and Plant Introduction from 1898 to 1928, is said to have personally introduced more than two hundred thousand species and varieties into the United States. Likewise, the American Acclimatization Society imported a variety of plants and animals, including an attempt to induct all of the bird species mentioned in Shakespeare’s works into New York City’s Central Park in the 1890s.

More than half of the plants considered invasive in North America were originally imported for their horticultural use. And the means we have for repelling them only inflict more violence on the landscape. Common techniques to “restore” landscapes today include large scale machinery for mechanical control, burning lands, dumping chemicals, and spraying pesticides. The "restoration" industry widely uses chemical and other means to poison our way into resurrecting an idyllic past.

Conversely, many other invited species were recast as essential to our sense of nature. The plants in our horticultural societies and botanic gardens, the insects we use for pest control, and our most popular agricultural crops and house plants overwhelmingly derive from imported plants and animals. This highlights another flaw in the argumentation of anti-invasive species activists. They are not concerned with the imposition of profitable monocultural cash crops that are now layered over indigenous agriculture. There is also no recognition or acknowledgement of the importance of foreign species in our everyday lives. It would seem that as long as alien plants know their rightful place as controlled commodities, their presence is tolerated. Sound familiar?

The Supreme Irony

Against the backdrop of this history, the rise of the “invasive species” discourse is at the very least ironic. After centuries of global expansion and the ecological decimation of the planet, the responsible nations insist that their “new Europes” are besieged by more recent immigrants from Asia, South America, and Africa. There’s a not-so-subtle trick at play here, often performed by colonist societies, where the settlers reimagine themselves (and their spoils) as the natives. Tracking the histories of “invasive” rhetoric allows us to understand how plant and animal quarantine laws developed alongside national exclusion acts. Seen through this long arc of history, invasion biology emerges as entirely a project of colonial consolidation, nostalgia and return.

This is only one way that nativist ideas have snuck into the environmental movement. Notable groups such as the Sierra Club and the Audubon Society were founded on racial anxiety. Further, about 40 years ago, white nationalist leaders deliberately and consciously sought to infiltrate environmental organizations (who were largely seen as liberal), in an effort to insulate themselves from charges of racism and xenophobia. This process is known as “greenwashing” or the “greening of hate.” Compelled by recent political movements, several large environmental organizations have recently pledged to reexamine their past and their mission. If this reckoning goes beyond the cosmetic, it will call the whole binary framework of nature (as in or out of place) into question.

Such a move will mean a colonial reckoning for invasion biology. As it stands, the field’s project, its language, and the biological nostalgia it summons, remain fundamentally un-ecological. We cannot control the world, even if we wished to. The ravages of empire have transformed not only human and cultural landscapes, but also ecological ones. And there’s no going back.

No species is well adapted anymore. We are already seeing plants and animals adapting to our changing climate regimes. Many are migrating into new territories that are better suited to their biologies. In light of this fast-changing world, we would be well advised to take the long view. Instead of indulging a nostalgic return to an imaginary past, we might consider how to repair ecosystems ravaged by the extractive logics of empire. A paradigm shift like this would yield a lot more than inoffensive language. It could have profound implications for policy and resource allocation. It would allow us, in theory and practice, to untangle and extract some of the deepest roots of our colonial pasts. Then, perhaps, something new could grow. ♦