‘I must have known giants have few friends

(The great lurk shyly in their private dens),

And found you hidden by a thick green wall

Of aerial roots.

Intruder in your pillared den, I stood

And shyly touched your old and wizened wood,

And as my heart explored you, giant tree,

I heard you singing!’

Ruskin Bond on banyan trees, A Song for Lost Friends

Trees are a puzzle. They seem fixed and permanent, yet they do move, not least through their seeds and aerial roots. They don’t speak, but as Bond as well as the authors of Cities and Canopies point out, they do communicate. Depending on how you look at it, trees can be like a flagstaff, adding a sense of identity to a place. Or they can be inter-generational source of lore and knowledge.

I grew up on Bengali folk stories of a particular kind of ghost that lived in a ficus tree. If you yawned under this tree at night, the ghost entered your body and ruined your digestion. Like much of folklore, this could have been based on some interpretation of malady: the fact that trees respire at night and so should be avoided. But the essence is that trees touch our lives in many ways. And the greatest strength of the book is that it embraces these many pathways, not restricting the narrative to just science or just myth.

Instead, to borrow Cities and Canopies‘s own metaphor, the book is a khichdi of information, anecdote and experience, flavoured variously in old texts, grandmother’s tales and journal articles. In an age where forests burn for weeks without an administrative response, and lakhs of trees are proposed to be felled for single projects (one proposed dam will cut about 3.5 lakh trees in Palamau tiger reserve), this is the kind of multi-layered information we need.

There are two strands of knowledge of immediate interest to India. One is the fact that trees are increasingly cut for city and other kinds of expansion, and saplings are planted in their stead. Examples are projects in Delhi, Mumbai, Pune and Bengaluru, among others. The others are fairly recent developments in understanding how trees communicate.

Scientists have called this the ‘wood wide web’, and the book’s authors Harini Nagendra and Seema Mundoli explain this in easily accessible language: trees have been known to communicate despair to other trees when threatened, which may cause the other trees to send out toxins to protect themselves. Trees also feed each other through the fungus in their roots, keeping alive tree stumps that don’t have leaves and branches.

The wood wide web, Nagendra and Mundoli argue, could mean that there are certain ‘mother’ trees in a place, and cutting large trees because they are too big, “over-mature” or getting in the way of a development project may harm all the trees in the area.

Science and wonder are two sides of the same coin and the book looks both in the eye. The authors devote episodic chapters to several iconic trees and their respective controversies – tamarind (not originally an Indian tree), eucalyptus (seen as a stubborn alien species), peepal and banyan (the last two will strangle and kill their host trees or break down buildings) and others.

In a heating, changing world, some of the words here are instructive. On a chapter on the tamarind tree, the authors write how a single one in Hyderabad’s Afzal park saved 150 lives in a flood. People who clambered on to the tree were ultimately saved. This reminds me of a story of the flooding Yamuna this year. A pregnant woman, flooded out of her house because of the rising river, climbed a tree along with her children. They spent the night among the branches of their arboreal rescuer till they were rescued.

Trees make cities in many ways, the authors write. They can be “intersections where nature is worshipped in the heart of the madding crowd.” And the worship of trees has recently also shown itself to be non-religious. There are citizen-led movements to save trees – whether for the trees of Delhi, meant to be axed for government colony redevelopment, or human chains made under the rain to save trees in Aarey, Mumbai, slated to be cut for a metro shed.

This is then a book written by academics but clearly not for academics. Enter the anecdote. There are two kinds of anecdotes here. One, the sort of thing you needn’t know but you really should – such as the fact that the name ‘coconut’ is derived from ‘coco’, meaning ‘monkey-face’ in Spanish. Lore that says the frangipani doesn’t have pods because the cobra destroys them, as frangipani is supposed to be a cure for cobra bite. That tamarind seeds come in various shapes, prompting descriptions like obovate (oval, narrow at the base), cuneate (wedge-shaped) and triangular.

Also read: An Interview With the Authors of ‘Cities and Canopies’

Then there is the anecdote that we must know because they add to the complexity of trees, and thus of nature as a whole – such as the fact that frangipani is also known as the immortal tree because it flowers even after being uprooted.

My favourite part is that the authors do not shy away from their identity as women, and this reflects in their insertion of recipes, traditional knowledge and games into the book. Nagendra’s grandmother told her that hair oil from banyan roots was good for her because it meant that, like the resilient banyan root, her hair would never stop growing. It describes games derived from the gulmohar, wherein parts of the flower can be used to make long, green, fake nails. In an age of instrumental views of nature centred around ecosystem services, these pieces of memory and frolic demonstrate that trees are ultimately beyond value.

“Science isn’t the only way to look at a tree,” Nagendra told The Wire. “Marvelling is another.”