Sapindus mukorossi aka Reetha

Sapindus mukorossi, or Chinese soapberry, belongs to the soapberry family, Sapindaceae. Kew places its native range in southern China. Other sources list a wider range across Asia. This includes Japan, Korea, India, Nepal, and parts of Southeast Asia. The tree grows in warm subtropical and tropical regions. In Nepal, it grows on open, rocky ground.

This fast-growing tree sheds its leaves and forms a rounded crown. Garden references give heights of 33–66 feet [10–20 metres]. Another account gives 39 feet [12 metres] as usual. Some trees reach 82 feet [25 metres]. Its crown can spread to 66 feet [20 metres]. The trunk grows straight and can reach 2 feet [0.6 metres] across. Its broad, rounded form suits sites with ample space.

Small white to cream flowers grow in large panicles. Bees visit the flowers and carry pollen between them. Sources place flowering from late spring into summer. The smooth fruits turn yellow to orange. Their pulp contains saponins, which make a lather in water. People have used these fruits for washing for thousands of years. The seeds also serve as beads for bracelets.

Grow Chinese soapberry in full sun, with soil that drains well. It prefers deep, fertile soil that stays moist. Yet it also grows in dry, stony, or poor soil. It accepts sand, loam, and clay where drainage allows. It tolerates mildly acid, neutral, and mildly alkaline ground. Plants For A Future lists USDA zones 8–12. Its separate UK zone 9 rating is not an RHS H rating. Growers can raise new plants from seeds or greenwood cuttings.

People plant this tree in gardens, near temples, and beside roads. It serves as an ornamental tree and a source of soap. Plantings have also helped restore eroded hillsides in the western Himalayas. Fruit lather cleans clothes, hair, and tarnished silver. Traditional medicine uses the fruit and seeds for several ailments. These records describe folk uses, not proof of safe treatment. They include uses for burns, lice, coughs, and dental problems.

The seeds have a limited, prepared use in food. People crush and boil them to make liquid for some Indian sweets. This does not make the raw fruit a safe snack. Its saponins can cause harm, though the human gut absorbs them poorly. The sources warn against eating large amounts of raw saponin-rich food. These compounds are much more harmful to fish. People have used the pulp to poison fish.