The Secret Life of Chalmugra

On a cold January morning in Pakke Tiger Reserve, I was walking along the Khari Nala trail when an unusual sight stopped me in my tracks. A large tree stood ahead of me, its trunk studded with big brown fruits, some larger than my palm, sprouting directly from the bark. They hung in thick clusters, running from the canopy all the way down to where I could reach them. I had seen cauliflory in photographs, but never so boldly displayed in the wild.

As someone who studies seed dispersal, my mind immediately leapt to the animals that might feed on these fruits. Their sheer size ruled out most birds. They were dull brown, silent, and carried no scent I could detect. I tried tugging one gently, but it wouldn’t budge. My field collaborator laughed: “Unripe fruits won’t come off. When it’s ripe, you can pluck it easily.”

A forest guard shared the local name — chalmugra or hooka. He added that civets visited the tree when it fruited, and that hunters sometimes waited nearby. Civets? I couldn’t smell anything; how were they sensing it? The question lingered as I learned its scientific name, Gynocardia odorata. Most online references discussed its medicinal oil, but almost nothing talked about its ecological relationships. I decided to follow the mystery myself.

I selected a few fruiting trees and set up camera traps pointing at their trunks. For nearly three weeks, the fruits remained hard and scentless. Then one morning, as I approached a camera, a sweet, jackfruit-like fragrance reached me from several metres away. The fruits had ripened. Some had already cracked open and lay scattered across the forest floor. It was finally time to see who had been visiting.

The cameras revealed what my own senses had missed.

For days before ripening, common palm civets (Paradoxurus hermaphroditus), masked palm civets (Paguma larvata), and Pallas’s squirrels (Callosciurus erythraeus) had been coming regularly and sniffing the unripe fruits as if monitoring their progress. They seemed to know exactly when the moment would arrive. And once the fruits softened and split, the tree transformed into a busy wildlife cafe.

At night, common and masked palm civets bit into the fruits, swallowing pulp and seeds together and dropping others as they fed. Bats hovered briefly, licking the exposed pulp and flying off with seeds held between their teeth. In the early morning light, bulbuls and thrushes pecked at the sticky, sweet flesh.

Rhesus macaques arrived in noisy groups, stuffing seeds into their cheek pouches before scampering away. Common and masked palm civets carried seeds off one by one, sometimes travelling surprisingly far. Capped langurs ate the unripe fruits whole like a piece meal, fruits so tough I couldn’t even pry them free.

While all this unfolded in the canopy and on the trunk, another drama played out beneath the tree. The soil was pressed with the hoofprints of sambar, barking deer, and wild boar, and many seeds lay crushed into powder — perhaps the work of porcupines. Additional cameras placed on the ground captured a second layer of the feast: Common and masked palm civets calmly chewing seeds and grinding them with slow determination, wild pigs gulping them down in huge quantities, and rats caching them under the leaf litter. Even civets returned to feed on pulp-covered seeds fallen from above.

It felt as though almost every frugivorous mammal in the forest visited this one tree.

Over the next several weeks, I began noticing the tree’s influence everywhere I walked. Civet scat glistened with Gynocardia seeds. Rodent caches lay tucked beneath dry leaves. Squirrels flicked seeds from branches with practised ease. Macaques spat out seeds after carrying them some distance. Some animals transported seeds far from the parent tree. Others destroyed them completely. But all were unwitting participants in the tree’s reproductive journey.

Studying these fruiting trees reminded me how much of the forest lies just beyond human perception. I had walked past the unripe fruits for weeks without noticing anything unusual, while civets and squirrels seemed to understand precisely when the fruits were ready. Nature communicates in ways we are not always equipped to perceive, through scents too subtle for us and ripeness cues refined over millions of years of coevolution.

The cauliflorous habit of Gynocardia brings its fruits within reach of an extraordinary range of animals. From bats and langurs in the canopy, to civets and macaques on the trunk, to boars, porcupines, and deer on the forest floor, its design invites participation from every level of the forest. 

When the chalmugra fruits ripen, the forest gathers. In the quiet of the night and the brightness of early morning, an entire community comes to feed. And through their feeding through mouths, cheek pouches, paws, and bellies, the tree scatters its seeds into the wider forest.

A single fruiting tree becomes a centre of abundance, a meeting point for species that rarely cross paths, a reminder that even in the vastness of a forest, one tree can hold the energy to bring everyone together.

And as I walked back along the Khari Nala trail, the sweet scent fading behind me, I realised that the mystery that had first stopped me wasn’t simply about how the fruit smelled or who fed on it. It was about how much is constantly happening around us, quietly and intricately, whether or not we are paying attention.