An invasive American shrub originally imported as an ornamental garden plant now infests more than 13 million hectares of Indian land and threatens 44% of the country’s forest cover, according to research evaluating two centuries of ecological spread. The species, Lantana camara, has expanded aggressively beyond domestic flowerbeds into tropical rainforests, mangroves, and semi-arid landscapes across the nation, creating an ecological crisis that has largely resisted eradication efforts.

The Two-Century Spread of an Ornamental Invader

Native to tropical Central and South America, lantana was transported across global maritime trade routes and arrived on the Indian subcontinent shortly after 1800. Historical data examined by researchers in PLOS ONE revealed that the plant was deliberately cultivated for its colorful flowers during the nineteenth century. Over the succeeding two centuries, the botanical import broke containment, replicating the destructive pathways it established across South Africa and Australia, and establishing a presence in more than 60 nations.

Instead of remaining a harmless floral decoration, lantana capitalized on disturbances within native ecosystems. Forest damage resulting from recurrent fires or severe floods opens the natural canopy, bathing the forest floor in intense sunlight. Lantana exploits this direct exposure to accelerate its vegetative growth and fuel massive reproductive bursts. Frugivorous birds consume the plant’s abundant drupes, dispersing seeds across vast, fragmented landscapes where the shrub rapidly colonizes new ground.

Chemical Warfare on the Forest Floor

Beyond its rapid dispersal, the shrub systematically alters soil and understory dynamics to monopolize surrounding resources. The plant actively synthesizes and secretes allelopathic chemicals directly into the earth, biochemically arresting the germination and development of neighboring flora. This invisible toxicity prevents native saplings from competing for sunlight, moisture, and root space.

Fieldwork conducted in 2017 and 2018 across three forest sites in Sagar, Madhya Pradesh, documented the staggering ecological toll exacted by this botanical takeover. Published in 2025 in Frontiers in Forests and Global Change, the study analyzed 60 designated research plots in tropical dry deciduous forests—an ecological classification that represents 40.9% of India’s total forest mantle, according to the India State of Forest Report 2019.

The inventory revealed a severe drop in native floral richness. In plots free of lantana, botanists recorded 132 distinct plant species. By contrast, plots colonized by lantana held only 98 species, confirming that nearly a quarter of local floral diversity disappears under dense infestations.

The shrub, which threatens 44% of India’s forest cover, covers over 13 million hectares.

Disrupting Carbon Dynamics and Forest Succession

The research in Madhya Pradesh examined the broader biogeochemical repercussions of the invasion, focusing on carbon balance within tropical dry forests. Overall forest carbon stood at 142.4 metric tons per hectare inside lantana-dense areas, compared to 153.7 metric tons per hectare in pristine, uninvaded stands. While the upper 50 centimeters of soil beneath lantana mats demonstrated an elevation in carbon—recording 73.1 metric tons per hectare versus 65.2 metric tons in unaffected soils—the suppression of juvenile tree regeneration presents an alarming long-term threat to the forest lifecycle.

By halting the recruitment of young native trees, lantana prevents the forest from replenishing its aging canopy. As mature indigenous trees eventually die, the overall carbon storage potential of the ecosystem risks severe destabilization.

The Dilemma of Scalable Containment

Two centuries of containment campaigns across India, Australia, and South Africa have routinely failed to reverse lantana’s spread. Physical removal and controlled burns often backfire, as exposure to fire actually stimulates lantana to surge back with greater vigor. While localized trials in Punjab combining chemical suppression with the immediate planting of rapid-growing native trees produced positive localized recovery, scaling such intervention across millions of hectares remains a profound logistical hurdle.

Smaller initiatives have sought to transform lantana biomass into commercial woven baskets and compost, but utilization alone cannot suppress the millions of hectares currently overrun. With climate shifts projected to widen the shrub’s hospitable range, researchers suggest management paradigms must shift from fantasies of absolute eradication toward durable, long-term ecosystem containment.