A single banyan tree will grow a forest of prop roots as it matures over a long lifetime.
Banyan is a common home and office houseplant, but in the wild it's a giant tree of Indian jungles. Banyan starts out life as an epiphyte growing on another tree where some fig-eating bird deposited a seed. As it grows, banyan produces aerial roots that hang down from horizontal branches and take root where they touch the ground. These vertical "prop roots" can create a forest on their own. Banyan can get 100' tall and, with its massive limbs supported by prop roots, spread over an area of several acres. A famous banyan tree near Poona, India, is said to measure a half mile around its perimeter and be capable of sheltering 2000 people. The large (5-10"), leathery leaves are like those of another home grown fig, the rubber plant (Ficus elastica), except that banyan's start out bronzy brown and hairy before maturing to glossy green and retaining just a scattering of hairs. They often have prominently marked veins. The figs are scarlet red, about a half-inch in diameter, and reportedly not particularly tasty. The cultivar, 'Krishnae' (Krishna fig or Krishna's cup) has leaves that are uniquely cup shaped at their bases.
The banyan tree is native to India, Sri Lanka and Pakistan. It is often planted around temples and is considered sacred by both Hindus and Buddhists. Banyan tree is widely cultivated in city parks and botanical gardens throughout the New World and Old World tropics.
Thin roots emerge from the banyan tree branches and hang like strings as they grow toward the ground. Once they're rooted in the earth these aerial roots thicken into trunklike structures able to support the weight of the wide-ranging branches.
Of course there is no such thing as a "houseplant." All plants grow outdoors, but some can be made to survive, even thrive, indoors. The banyan tree is one plant that can remain indoors all year long. Repot every 2-3 years, but like the rubber plant, banyan is best kept a little on the pot-bound side. The shoot tips can be pinched back to promote branching.
Light: As a houseplant, banyan should be positioned in an area where it gets half shade or moderately bright light. It does not need the bright light so often demanded of plants grown indoors. Outdoors, grow in half sun to partial shade. Moisture: Outside established banyan trees are drought tolerant. As a houseplant, banyan likes a soil that is well drained but kept moderately moist. Allow soil to dry almost completely, then saturate. Underwatering and overwatering can cause leaves to yellow and drop. Hardiness: USDA Zones 10 - 12. Banyan is damaged by frost but will recover from brief periods of freezing weather. Houseplants should be kept at 70-80 F in the summer and above 55 F in winter. Propagation: Banyan can be propagated by rooting tip cuttings or eye cuttings. To make an eye cutting, cut off a piece of stem about a half inch below and above a leaf. Insert the stem piece and a little of the petiole (leaf stalk) into the rooting medium. To reduce evaporation from the leaf surface, you can roll the leaf and secure with a rubber band. In a couple weeks roots and a new shoot should develop at the leaf axil.
The handsome (and rugged) foliage and its ability to grow in low light conditions have inspired homeowners for centures to grow them indoors.
A banyan tree makes a fine specimen and shade tree if you have your own tropical botanical garden and a few acres to spare. Otherwise, grow this evergreen rubber plant look-alike in a container in the house. In India, the edible leaves are used as plates.
The fig "fruit" is actually a hollow, globular receptacle with hundreds of small fleshy flowers facing each other on the inside. Figs are pollinated by a tiny specialized wasp that enters the receptacle through a small opening. Each flower inside the receptacle then produces a tiny fruit containing seeds.
The foliage and milky sap of all figs can sometimes be an irritant to skin and eyes for especially sensitive people, but most people are not effected.