Humboldia may sound hefty, but it is, in reality, a sweet-flowering tree found in some of the most serene woods of the tropics. A botanical beauty that has fascinated scientists and taxonomists for decades.
Kerala’s own green treasure house, the Agasthyamala Biosphere Reserve, a 3500 sq.km stretch at the southernmost tip of the Western Ghats, is home to this genus.
So far, 11 species of Humboldtia have been identified. Ten occur in the Western Ghats and one in Sri Lanka, making the genus largely endemic to the Western Ghats.
One variant spotted beside a gurgling brook in the Shendurney Wildlife Sanctuary in Kollam in 2010 took 12 years to reveal its secret. Another four years of study and scrutiny followed.
And finally, it was recently recognised as Humboldtia nairiana, a new species named after veteran botanist and Kerala Academy of Sciences president G M Nair.
Former director of the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Nair is remembered for mentoring young researchers eager to explore forests in search of nature’s hidden gems.
And the JNTBGRI team that discovered the species — E S Santosh Kumar, S M Shereef and T Sabu — had once benefited from his guidance.
Their discovery is the latest reminder of the remarkable biodiversity hidden within the Western Ghats. Notably, a few years earlier, the same team had discovered another rare and endemic Humboldtia species at Ponmudi. They named it Humboldtia ponmudiana after the place where it was found.
The naming and formal confirmation of a plant often happen years after its discovery. The process follows global standards laid down in the International Code of Nomenclature.
“We, as scientists, have to be patient,” says Santosh. “First, we explore with calm alertness. Then we rear the samples in our until they flower. After intensive scrutiny, we send it to experts to confirm.”
Santosh adds that researchers usually don’t go looking for new species randomly. “While studying a particular plant group, we explore the possibility of variations and search for them during our field trails. That’s often when we stumble upon new species,” he says.
“We then bring back seeds or seedlings and conserve them under conditions that closely mimic their natural habitat.”
He recalls the journey that eventually led to the identification of Nairiana. Rewind to 2010. On a characteristically tropical morning, Santosh and his teammates set out for the outer reaches of Shendurney Wildlife Sanctuary.
“We were accompanied by forest staff and tribal guides. They know the terrain inside out,” he remembers.
The team was not specifically searching for Nairiana. It was one of their routine expeditions to locate another Humboldtia species called decurrens (Kattashokam).
“Decurrens and vahliana (Attuvanchi) were first documented during the colonial era. We have always followed the trail of these trees, whose flowers show subtle variations,” Santosh explains.
“Some have a faint, sweet fragrance while others do not. Colour varies, and so does the smoothness of the bark.”
The team travelled along the Ponmudi–Kulathupuzha route before turning towards Pandimotta, one of the highest elevations in the Shendurney forests. Vehicles could go only as far as Cheenikkala, a forested midland.
Forest research, they say, is a slow process. Researchers spend hours moving slowly through forests, examining plants, taking notes and comparing characteristics.
“Good maps, compasses and provisions are essential, especially in areas where communication networks are absent and overnight stays may become necessary,” says Shereef. “Once daylight fades, we camp somewhere in the woods.”
It was during one such slow walk through the Cheenikkala forests that the team noticed something unusual.
“We were looking for variations of decurrens when we spotted a tree with softly pink flowers and very little fragrance. The bark was exceptionally smooth. That suggested it might be a variation,” he says.
Many Humboldtia sightings occur along forest streams where researchers pause for a break. In this case too, the tree was found beside a stream in Shendurney.
“Yet we never imagined it was a new species. We brought sprouting parts back to JNTBGRI and reared them. The tree flowered in 2022. Only then did we realise it was a distinct species rather than a variation of decurrens,” says Sabu.
The discovery highlights how much remains unknown about the southern Western Ghats.
According to the latest JNTBGRI enumeration, which is yet to be released, around 3,600 of Kerala’s nearly 5,000 rare plant species are found within the Agasthyamala Biosphere Reserve. Nearly one-third of these are endemic.
“There is so much more waiting to be discovered,” the team says.
Sabu stresses that identifying and conserving tree species is vital for future generations. “No plant on earth is useless,” he says. “Humboldtia species discovered earlier were known to possess significant medicinal value. Who knows how Humboldtia nairiana may benefit humanity in the future? Rare plants are rare for a reason.”
According to the team, the shortage of trained manpower with a passion for exploration is hampering Western Ghats research.
“Our land has a legacy of botanical exploration since the 1600s. But armchair taxonomy is now replacing fieldwork at a time when documenting biodiversity is more important than ever. The lack of trained manpower is another problem,” says Santosh.
Field research demands endurance and resilience. It often requires spending days in remote forests.
“Finding Humboldtia vahliana, brononis (Kadu Ashoka), its variant raktapushpa in Wayanad forests, bourdillonii (Adimundan) in Idukki, and even decurrens in the southern Western Ghats required tremendous effort,” he says.
Some expeditions required the team to spend nights in the forest.
“We would light fires in places considered safe by forest officials or tribal guides. Usually, these were beneath cliffs or inside caves. We slept in sleeping bags and cooked our own food. The explorations were exciting, though occasionally dangerous when wild animals appeared,” says Santosh.
He recalls one such journey when a tusker blocked the jeep carrying his team.
“We wondered whether the elephant would destroy the vehicle first or kill us first,” he laughs. “There are also countless snakes in these forests. We have to remain alert. We wear anti-leech socks and take other precautions.”
Though not always dramatic, adventure is an inseparable part of taxonomical research. Despite the hardships, the researchers describe the experience as deeply rewarding.
Their searches for species have taken them into some of the least accessible corners of the Western Ghats.
“Many of these landscapes remain closed to the public for ecological reasons. As a result, only a handful of people ever witness their beauty,” says Santosh.
“The deep forests are a once-in-a-lifetime experience. Surreal — I can’t explain it. The forest department is understandably cautious about opening them up to the public. Places in Munnar, Eravikulam and the southern Western Ghats hold extraordinary ecological wealth.”
Searching for plants, therefore, is not merely a profession or an academic pursuit. It is an expedition that demands an explorer’s spirit.
Funding constraints, Sabu adds, are another challenge.
“The downside is that we may lose the rare ecology of the Western Ghats before it is even documented,” he says. “This is happening worldwide. Nearly one-third of rare species disappear before humanity even becomes aware of them.”
After all, every new species adds another piece to the puzzle of understanding the Western Ghats — and the world we live in. And somewhere in its forests, beside a stream or beneath a canopy, they are waiting to be found.