New Delhi: From manoeuvring maddening city traffic and nearly getting stung by honey bees to taking baths in the middle of nowhere after getting bitten by red ants, these are just a few challenges Kolluri Sankara Rao faced when documenting trees in Bengaluru.
Rao, a visiting professor and distinguished fellow at the Centre for Ecological Sciences at the Indian Institute of Science, enthusiastically recounts tales of his adventures—and occasional embarrassments—while compiling a first-of-its-kind book on the trees of the south Indian city. The book Trees of Bangalore was released on 8 November, aligning with the 90th anniversary celebrations of the Indian Academy of Sciences, its publisher.
Indian cities are witnessing a quiet botanical boom. A growing tribe of tree enthusiasts and experts is racing to document the urban canopy. Since the mid-2000s, books and guides have mushroomed showcasing the rich tree diversity of Delhi, Mumbai, and Chennai. This citizen-led initiative is uncovering hidden treasures and fostering a new appreciation for urban green spaces.
In the process, some pleasant surprises were in store—from the Rudraksha tree to the Jamun family.
Trees of Bangalore chronicles the city’s rich botanical history, revealing a fascinating narrative of urban development and environmental stewardship. The book showcases over 800 species from different wooded areas, most resulting from the city’s various tree-planting initiatives over the centuries. These efforts span from early programmes in the 1760s under Haider Ali and Tipu Sultan to the 1970s green surge that earned Bengaluru the ‘Garden City’ tag. Replanting efforts at the Indian Institute of Science (IISc), supported by then director Professor P Balaram in 2010, continued this legacy.
“Often, I would be mistaken as a thief or burglar hopping into compounds of private properties as I take shots of trees to catalogue them,” said Rao. These visits to residential colonies were a bag of mixed experiences. Sometimes, he was chased away by the dogs in the household courtyard. Other times, the owner would welcome him and eagerly share rich stories about the plantations on their land. Once they learned about his project to compile a repository of the city’s trees, many were glad to help.
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Remarkable tree diversity
Rao’s journey of documenting Bengaluru’s trees is a story of passion and dedication that spans decades. Although he is a trained botanist, career opportunities led him to IISc’s Department of Biochemistry. Yet, his weekends were reserved for exploring the city and its outskirts, where he tirelessly collected data on its diverse tree species.
For nearly 35 years, Rao kept detailed handwritten notes, capturing each tree’s location, characteristics, and unique features. With the advent of digital cameras post-2006, high-quality imaging became more affordable, he enriched his records with vibrant photographs—a significant upgrade from the costly printing technology that preceded it. After retirement, Rao compiled his vast collection into two volumes, totalling over 1,000 pages, complete with coloured images of nearly 600 trees and over 100 woody climbers for easy identification.
“In my opinion, no city is as fortunate as Bengaluru, for its remarkable tree diversity and extensive inventory,” said Rao.
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Delhi’s tree documentation
Pradip Krishen, environmentalist and author of Trees of Delhi: A Field Guide, transformed the cataloguing process into a playful challenge. During his strolls through Delhi’s leafy neighbourhoods—Nehru Park, Lodhi Garden and Sunder Nursery—he would test himself by identifying specific species through careful observation of their leaves.
“Gathering information on indigenous trees—what they are and where they came from—was straightforward. But exotic trees proved to be the real troublemakers,” said Krishen. “You don’t know what the tree is or where to begin uncovering its origin—whether to look up the flora of Brazil, Australia, South Africa, or elsewhere in the world.”
Most of these trickier exotic varieties were exclusive to Sunder Nursery, the Delhi government’s horticultural experimentation hub. For these, simply recording leaf patterns wasn’t enough. “They neither flowered nor bore fruit, and the internet was still in its early stages, making identification challenging,” Krishen explained.
Without a technical background, he reached out to visiting botanists who might lend expertise. He even arranged wood analyses of these failed plantation species at labs in Dehradun, yet the specific details of some species remained elusive.
Just as he was on the verge of giving up on identifying one particularly puzzling tree, he came across a 50-foot version of it during a visit to a botanical park in Sydney, Australia. “Immediately, I plucked a leaf and kept it in my pocket,” he recalled, “bringing it back with me to Sunder Nursery—finally solving the jigsaw puzzle.”
For Krishen creating a field guide about the trees of Delhi wasn’t just about documenting trees in the city, it was about connecting people with the environment. He wanted to produce a guide that anyone in Delhi could use to identify trees in their neighbourhoods.
“I met people who carry my book in their car, so when they stop at a traffic light and spot a tree with beautiful leaves or bark, they quickly reach for it, hoping to identify the tree before the light changes,” said Krishen. These activities enrich citizens’ experiences, helping them appreciate the rich tree heritage of their city.
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Finding endangered species
Amid the concrete jungles of Bengaluru, surprising secrets lie hidden in plain sight. Tree species that are disappearing from their natural habitats are thriving in urban landscapes, nurtured by unknown hands. The origins of many of these trees remain a mystery to enthusiasts, they still wonder who planted them and tended to them with such care that they now flourish in bustling cities.
“I never expected this species of Rudraksha— found exclusively in Australia or Southeast Asian countries—to be thriving in the urban surroundings of Bengaluru,” Rao told ThePrint.
Bengaluru’s weather—with its moderate temperatures, relatively low rainfall, and lower humidity—isn’t exactly the tropical paradise that these Rudraksha trees typically call home.
The tree census also revealed some endangered species related to the jamun family, once thought to be gone, now flourishing on the sprawling campus of Mahatma Gandhi Botanical Garden, University of Agricultural Sciences. These species hold the potential to help revive the wild ones that are disappearing due to urbanisation, habitat loss, and other human-made factors.
“These discoveries highlight the dedication of the curators at these institutions in protecting nature,” said Rao. “It’s a prime example of the city’s efforts in ex-situ conservation—preserving species outside their native habitats—and showcases its often-overlooked environmental wins.”
(Edited by Theres Sudeep)