In the capital of the Indian state of West Bengal, tourists flock to see what at first glance looks like an expansive forest. Branches create an expansive canopy over the Acharya Jagadish Chandra Bose Botanical Garden — about the size of a Manhattan city block. But the most interesting thing about this collection of plant life is that it's not a collection at all; it's one massive tree, known simply as the Great Banyan Tree, and all those apparently distinct members of a forest are actually one of 3,600 aerial roots.
"The largest banyan tree can be found growing in a botanical garden near Kolkata (formerly Calcutta), occupies the better part of five acres, and is more than 250 years old," Erin Alvarez and Bart Schutzman, both lecturers in the environmental horticulture department at the University of Florida, explain via email.
If you're wondering how in the world a single tree could cover about 14,500 square feet (1,347 square meters) of space, grow branches as high as 80 feet (24 meters), and thrive over two and a half centuries, it's time to get to know a special species known as the banyan.
Understanding the Banyan's Roots
Alvarez and Schutzman say the banyan's history is rooted (pun intended) in South Asia. "Only one species from India — Ficus benghalensis — was the original banyan, named after the Hindu traders or merchants that conducted business under the shade of the species," the duo write via email. "Now, the term is used generically for several species of Ficus that have a similar life cycle and belong to one group of fig species (Urostigma)."
These days, when people refer to a "banyan" they could be referring to any one of the 750 species of fig trees that are pollinated only by a specific species of tiny wasps that breed inside the fruit of their partner trees. All banyans fall under the super cute and not-at-all-threatening-sounding category of "strangler figs." This means the trees grow from seeds that land on other trees, sending their own roots down to smother their hosts and then growing into smaller, branch-supporting pillars that look like new tree trunks.
"These plants all start life as a seed that germinates on another tree, grows as a vine dependent on the tree for support, and eventually strangles its host tree, subsuming its structure," Alvarez and Schutzman write. "Later, roots grow from outward-extending branches and reach the ground, becoming trunk-like and expanding the footprint of the tree, sometimes gaining it the colloquial name of a 'walking tree.'"
And while Kolkata's Great Banyan is by far the greatest of them all, banyans as a species dominate, size-wise — at least in broadness: they're the world's biggest trees in terms of the area they cover. When it comes to overall volume, however, they lose to the giant sequoia, a species led by a 2,000-year-old tree named General Sherman living in California's Sequoia National Park that's about 52,500 cubic feet (1,487 cubic meters) in volume.
Cultural and Historical Significance
The banyan is considered a particularly meaningful tree in India and other parts of the world, with rich historical and spiritual ties. Referred to as "the Vata-vriksha," in India, the banyan is associated with the god of death, Yama, and is often planted near crematoriums outside of villages. In Hinduism, it's said that the deity Krishna stood beneath a banyan tree at Jyotisar when he delivered the sermon of the sacred Sanskrit scripture, the Bhagavad Gita. And Hindu texts written over 2,500 years ago describe a cosmic 'world tree,' that references an upside-down-growing banyan that has roots in heaven and extends a trunk and branches down toward Earth to deliver blessings. Over centuries, the tree took on significance as a symbol of fertility, life, and resurrection. The banyan also served as a source of medicine and food for centuries, and the bark and roots are still used today to treat a variety of disorders, particularly in Ayurvedic medicine.
According to historians, Alexander the Great and his army were the first Europeans to encounter the banyan when they arrived India in 326 B.C.E. But it was when the British invaded India that the tree took on a newly dark purpose, often used as gallows to execute rebels who resisted their rule. By the 1850s, hundreds of men were hung from the branches of banyans. When India gained independence, the people reclaimed the banyan as well, making it the national tree.
The Banyan of Today
Banyans are native to and thrive in India and Pakistan but these days, variations of the majestic trees can be found in areas of Florida. "These Ficus species can only grow in the tropical and subtropical areas of the world because they are not sufficiently cold-hardy to live outdoors in colder climates," Alvarez and Schutzman write. "In some places such as south Florida, the False Banyan, Ficus altissima, has become invasive."
There's also one famous species representative on the Hawaiian island of Maui: the Lahaina Banyan, planted in 1873 and presented to the sheriff by missionaries from India. Now 40 feet (12 meters) tall, the Lahaina Banyan has a canopy circumference spanning a quarter-mile (0.4 kilometers).
Today's banyans aren't just beautiful and symbolic — they also come in handy for modern purposes. "This ability of tiny Ficus roots to become trunk-like structures is used by the people of Meghalaya, India, to create foot bridges across streams that become raging rivers during the monsoon season," Alvarez and Schutzman write. "They weave the tiny roots of our well-known rubber tree (Ficus elastica) together to cross the streams. They enlarge and form sturdy structures that can live 500 years or more and do not get washed away during the storms."
And while you may be tempted to grow your very own majestic banyan now that you know the unique magic of their roots (literal and figurative), you may have to settle for a painting or photo print homage. "The best way to care for them is to give them plenty of space and warm, wet, humid weather — so most banyans don't make very good plants for regular home gardens," Alvarez and Schutzman write. "A few species have adapted to indoor environments and can be grown in bright indirect light with regular watering, however they are not as long-lived as their relatives in the wild."