Vilayati kikar: The making of a supervillain

I will take this town

I will make it my own

I will walk the street

I will feel the beat

Of the sun on my face

I will say I like it here

And I will stay.

– Song of the Migrant  by Anonymous 

I found the above poem on one of the walls of my current workplace in Hyderabad. As a newcomer to the city, these verses provide me with motivation and a sense of solidarity. I moved to Hyderabad in 2024, leaving my family home in the outskirts of Delhi for the first time. Navigating unfamiliar weather, terrain and culture was challenging, despite my privileges. My colleagues at the Hyderabad Urban Lab (HUL), a research institute, work with migrant workers who routinely experience discrimination at work, struggle to find dignified housing, and are subjected to verbal and physical abuse. Leaving home is painful, yet migrants and refugees are looked at with suspicion, fear, resentment, even anger. This has been true for humans and is increasingly becoming true for non-humans as well.  

In recent years, popular news and science platforms in India have been publishing extensively about “invasive species” such as lantana, water hyacinth, and congress grass, warning citizens of the risks these species pose. Invasive species are often described as dangerous intruders that spread unabated, eradicating native creatures in their way. Terms associated with invasive species, such as “exotic”, “foreign”, “coloniser”, and “alien”, encourage an emotive response and impulsive action. And yet, there is no consensus among scientists on what an “invasive” species is – some scholars even identify human beings as invasive.

Biological invasion: myth-busting

National Geographic Encyclopedia broadly defines an invasive species as “an organism not native to a particular area that causes great environmental and economic harm”. Not all non-native species become invasive. In plants, scientists have identified shared traits among invasive species, such as high reproductive potential (the ability to produce a large number of progeny), enhanced seed dispersal capacity, and longer seed viability. A 2024 global study found that the percentage of non-native species becoming invasive varies between 7 and 33 percent. Variations depend on climate, geography, and other environmental factors. For instance, the likelihood of invasion is higher in islands than in mainland ecosystems.

So, what determines whether a non-native becomes invasive? 

Invasion science offers several theories. One of them is the enemy-release theory, which argues that a plant species’ population may explode in a new habitat due to the absence of its natural predators. For example, the St. John’s Wort plant had become invasive in New Zealand in the 1930s, but its population was controlled when its natural predator, the St. John’s Wort beetle, was introduced from Europe. However, using predators to control the spread of invasives (without rigorous testing) is risky because the control species might itself proliferate and become invasive. 

Another theory to explain invasion is the fluctuating resource theory, which contends that the vulnerability of a plant community to invasion depends on the amount of unused resources. Non-native species require resources such as sunlight, water, and nutrients to establish themselves. If these resources become available, for instance, due to a disturbance that removes the native vegetation, the habitat is ripe for the spread of a newcomer. 

A more cohesive theory is the niche opportunity theory, which explains invasion as the result of unused resources, absence of enemies, environmental opportunities, and a combination of these factors. On local scales, experiments have shown that the greater the diversity of a habitat, the less likely it is for a new species to spread and dominate. Thus, an invasive species is not villainous or stealthy by itself; rather, it benefits from existing vulnerabilities and a lack of diversity in an ecosystem.

The making of a foreigner

I worked in the Forest Department of the Delhi Government between 2020 and 2023. During this time, I realised that the vilification of invasive species erases nuances, and the native/invasive binary must be challenged. I illustrate my argument here using the case of Prosopis juliflora, a species characterised as invasive in India. Its origins can be traced to South America, Mexico, and the Caribbean. 

I first encountered this tree in 2016 during my undergraduate studies at the University of Delhi, where my Environmental Studies professor labelled every tree in the college campus except for one. Pointing towards its twisted trunk with a dark, gnarly bark during a tree walk, the professor told us that this tree shall remain unmarked – it was bad, invasive, and foreign. He called it vilayati kikar, with vilayati meaning foreign in Urdu, and kikar being another word for the babool tree (Vachellia nilotica), a native species which comes from the same sub-family as P. juliflora.

I was fascinated by the idea that a tree could be “bad”, having spent my childhood entangled with trees. I came across media reports that characterised it as an “ecology threat” that must be eliminated. Convinced by the narrative, I spent my final semester in college filming a documentary, Green Gone Wrong, which narrated how this tree had come to ‘invade’ Delhi’s flora. 

The narrative that P. juliflora was an invader was popularised in the 2000s. In 2006, Pradip Krishen, a historian and filmmaker-turned-ecologist, published Trees of Delhi, a field guide that made Delhi’s trees accessible to non-botanists. A much-needed change from jargon-filled botanical identification texts, Trees of Delhi inspired many Delhiites, including me, to take up tree-spotting as a hobby. 

Krishen’s book discusses colonial greening programmes in the Delhi Ridge, initiated during the making of the imperial capital of New Delhi in the early twentieth century. The ridge is the northernmost stretch of the ancient Aravallis. This rocky landscape is protected as a Reserved Forest under the Indian Forest Act of 1927. The British empire’s planners desired a green backdrop for the Viceroy’s Palace (now the Rashtrapati Bhawan), in the style of European cities like Versailles, France. The grazing land from nine villages was acquired, fenced, and reserved. Only those species were planted that the colonisers deemed ‘aesthetic’; The 1913 colonial Scheme for Afforestation of the Ridge read, 

[f]rom an aesthetic point of view the ridge is not a pleasant sight… As it forms the most conspicuous object on the horizon when seen from the site proposed for New Delhi it is desirable that it should be made more attractive in appearance by covering its slopes with a green mantle of vegetation.

The Delhi Ridge is a dry landscape, suited to support an open-canopied thorn forest. Instead of the native, slow-growing species, the planners chose fast-growing species from the Himalayan terai and also non-native species like Prosopis juliflora. Krishen wrote that the “vilaiti keekar would come to dominate Delhi’s flora and become the principal cause for a number of species on the ridge edging towards local extinction. Its success was startling, and Delhi has paid a high price for its extinction.” With this proclamation in an influential field guide, the public’s and media’s perception of P. juliflora was forever changed. It became the dreaded vilayati kikar. 

Interestingly, earlier documentation of the flora of the Delhi Ridge described P. juliflora in an innocuous manner. In Flora of Delhi (1963), botanist J.K. Maheshwari wrote, 

the trees comprising the perennial vegetation of the Ridge are both indigenous and introduced… Among the latter, the most noteworthy example is Prosopis juliflora, an evergreen, spiny tree, native of the arid regions of Mexico and Central America. It is very common on the Ridge and has become part and parcel of the native flora.

Similarly, the 1991 booklet The Delhi Ridge Forest: Decline and Conservation, brought out by the citizens’ group Kalpavriksh noted: 

there are a large number of introduced trees and shrubs which have in time, become naturalized. Most common is Prosopis juliflora, commonly known as the Kabuli or Vilayati or Mexican kikar… The tree has become naturalized now, and is very similar in appearance to the native Babul.

The cover of the booklet even featured a sketch of P. juliflora! The shift in the narrative around this species is stark.

Delhi’s war on vilayati kikar

The implications of this new avatar of P. juliflora went beyond popular perception. Politicians, bureaucrats, judges, and environmentalists took note, initiating several high-budget, large-scale projects to rid the ridge of vilayati kikar. One such project began in March 2019, when the Delhi High Court introduced a novel form of justice delivery in the capital: plantation to compensate for crimes. From drug patent violations to domestic disputes and even a Bollywood film credit contestation, Justice Najmi Waziri began ordering guilty parties to plant trees in the Delhi Ridge in sections renamed Insaaf Bagh (Garden of Justice) and Maafi Bagh (Garden of Forgiveness). The judge argued that the ridge must “always remain green” and bemoaned that it was plagued by invasion. 

The March 2019 order reads, 

Vilayati Kikar (Prosopis juliflora)…quietly spreads over a large area. Its canopy gives the impression of a green cover but provides no real shade or carbon absorption.

The influence of the narrative on invasive species from Pradip Krishen’s Trees of Delhi is evident in the court documents; in fact, Justice Waziri even quoted the field guide in one of his orders. 

The Insaaf Bagh and Maafi Bagh plantations turned out to be problematic. The initial species list for the plantation provided by the court included broad-leaved, evergreen trees, which struggled on the ridge and had to be watered extensively in a resource-sparse landscape. Since plantation targets were massive, saplings were planted closely, wringing the soil of moisture and nutrients. As an employee of the Forest Department, I was once tasked with producing a report showing that the failure was due to Prosopis juliflora, but this proved challenging because to me, it was clear that the evergreen plants were struggling because they were out of place, not the vilayati kikar. 

As my explorations of the ridge became more routine, I also began to question whether it was actually an invaded landscape with little native species diversity. It was true that P. juliflora and other non-natives populated the edges of the ridge, but the more inward I ventured, the more native species I came across – especially tracts of Anogeissus pendula, the habitat specialist of the ridge and the ‘flame of the forest’ Butea monosperma that lit the ridge with its seasonal fiery orange-red blossoms.

Then there were the native thorny species that are adapted to withstand the harsh climate and terrain. Sadly, they were often mistaken for the supposedly villainous vilayati kikar by on-site staff and were cut and pruned as a result. The plantation drives also resulted in the removal of understorey plants (the ground layer of vegetation) to make way for the evergreen natives. I couldn’t help but see this as further destruction in the name of ‘green justice’.

Alternative ways of thinking about invasives

Let us, for a moment, leave the persecution of natives in the name of invasives aside. Is the crackdown on vilayati kikar in Delhi ecologically meaningful to begin with? Recent research suggests no. For example, a 2017 article in Tropical Ecology, based on a study conducted in the Delhi Ridge, revealed a positive association between the presence of P. juliflora and native species. That is, the authors showed that it acted as a “nurse tree”, facilitating the regeneration of native flora under its canopy.

Another 2022 article in the journal Plants analysed plant networks to demonstrate that natives co-existed with invasives in the Delhi Ridge. The study also found that Lantana (another invasive plant) and P. juliflora excluded each other, forming cliques with natives but not with each other. Further studies are needed to explore the impact of P. juliflora on native plant diversity in the ridge. However, it is clear that current research does not validate the eradication of this tree, especially since attempts at removal have had unintended – and potentially dangerous – consequences.

How can we make sense of the curious behaviors of non-native species, especially in urban ecosystems? We can begin by challenging the pristine imagination of nature and the notion of restoring a seemingly pure and perfect ecological past. An important lens for this is “novel ecosystems”, proposed by ecologists Richard Hobbs, Eric Higgs, and James Harris in an influential 2009 article. The authors argued that the emergence of ecosystems that are different from past versions is inevitable due to human activities. The resources needed to force ecosystems back in time and maintain those states would be insurmountable. 

However, rather than dissuading practitioners from practicing ecological restoration, Hobbs, Higgs, and Harris urged practitioners to identify cases of “novel ecosystems”, where biotic and abiotic changes over time had created new associations which would be resilient to further change. In cases where restoration would be achievable and realistic, the past could serve as a reference point, but in the case of novel ecosystems it would be more meaningful to put in efforts into understanding new components and processes, and in working with – rather than against – them.

In the book Beyond the War on Invasives (2015), teacher and farmer Tao Orion describes science and policy response to invasives as an “unexpected war”. Orion notes that the label of “invasive” elicits fear and frustration, which prevents exploration into the causes behind their presence and meaningful engagement with land. My experiences with narratives and actions around Prosopis juliflora in Delhi have been similar.  

In Botany of Empire (2024), Banu Subramaniam, an interdisciplinary plant scholar deploys frameworks from queer studies and disability studies to investigate botany’s colonial roots and practices. She sees xenophobic responses towards foreign plants, animals and humans as connected. When terms like “invasive” and “foreign” are transplanted onto plants, biases and violences also get transferred. Subramaniam writes, “We should challenge native and foreign as labels for humans and plants. We need new vocabularies and new stories to narrate life on earth.” 

History, roots, and ecologies

I resigned from the Delhi Forest Department in 2023, disillusioned after my encounters with rigid narratives and violent actions towards creatures in the ridge. I wanted to conduct ecological research but also create meaningful action. Where would my work be situated? My friends wanted to “return to their roots”, to work in the places their families had historic ties to. I could find no such roots. All four of my grandparents migrated during the Partition of 1947 from different parts of West Punjab. I grew up hearing stories of places I had never been to. I would hear classmates talk about traveling back to their ancestral villages and towns during vacations, but there was no going “back” for us. And so I spent most of 2023 travelling in search of a study site. At a workshop in Goa I met Anant Maringanti, Director of Hyderabad Urban Lab, who invited me to visit Hyderabad and explore it through an ecological lens.

Hyderabad and I clicked immediately. This was a city historically accepting of migrants. The local language Dakhni, a blend of Urdu, Hindi, Kannada, Marathi and Telugu was accessible to just about everyone. The arid landscape of Hyderabad reminded me of the Delhi Ridge, and I felt like I could put down some roots. The past year has been challenging but the city has been kind, and I have tried my best. 

My grandparents were forced by the 1947 Partition to migrate to independent India in what was the largest movement of human beings in the history of the world. Many refugees, including my maternal grandmother, stayed in camps and colonies part of the Delhi Ridge landscape. They built new lives on this side of the border, new connections and ways of living. Much got erased, and younger generations increasingly felt alienated and rootless. As a descendent of the peoples who crossed the Ravi River, never to return home again, I feel a sense of kinship with species deemed “invasive”, “foreign”, and “exotic”. There is an urgent need to bring nuance into our engagement with creatures of all kinds, to stop imposing an imagined glorious past on people and ecosystems, and to imagine and create restoration projects that support new associations rather than weeding them out.

Note about the featured image: The photo by Kush Sethi shows Nivedita, during one of her surveys of the Delhi Ridge, with the Rashtrapati Bhawan (formerly Viceroy’s Palace) seen in the horizon. The ‘vilayati kikar’ tree was introduced to green the backdrop of the Palace during the colonial period.