They do actually grow on trees Strychnos spinosa (Monkey Apple).
Gathering of Monkey Balls is done by unemployed people in rural areas, and provides a valuable source of income to families who would otherwise have little or none. The harvesting of the balls also protects the trees from being cut for firewood. After local villagers harvest the balls, the skin is then removed and the balls are dried for nearly 12 months. In the workshop the balls are then made into different products with different finishes. After almost a year, local artists decorate the
balls – no two balls are alike.