Local names:
Bengali (ritha), Chinese (wuhuangzi,youzhuzi,feizaojia), English (tree of Northern India,soap-nut tree,Chinese soapberry), Hindi (aritha,dodan,manmar,rithan,thali), Nepali (ritha), Sanskrit (arishta,phenila), Trade name (Chinese soap berry)
Sapindus mukorossi is a fairly large, deciduous tree, usually up to 12 m in height, sometimes attaining a height of 20 m and a girth of 1.8 m, with a globose crown and rather fine leathery foliage. Bark dark to pale yellow, fairly smooth, with many vertical lines of lenticels and fine fissures exfoliating in irregular wood scales. Blaze 0.8-1.3 cm, hard, not fibrous, pale orange brown, brittle and granular. Leaves 30-50 cm long, alternate, paripinnate; common petiole very narrowly bordered, glabrous; leaflets 5-10 pairs, opposite or alternate, 5-18 by 2.5-5 cm, lanceolate, acuminate, entire, glabrous, often slightly falcate or oblique; petioles 2-5 m long. Inflorescence a compound terminal panicle, 30 cm or more in length, with pubescent branches. Flowers about 5 mm across, polygamous, greenish white, subsessile, numerous, mostly bisexual. Sepals 5, each with a woolly scale on either side above the claw. Fruit a globose, fleshy, 1-seeded drupe, sometimes 2 drupels together, about 1.8-2.5 cm across. Seed 0.8-1.3 cm in diameter, globose, smooth, black, loose in dry fruit.
Ecology
The species is native to China and Japan
Native range
China, Japan
There are 700-800 seeds/kg. Fruits are collected from trees or from the ground after falling, sun dried and stored. Gentle cracking of the pericarp releases the seeds. Seeds retain viability for 1-2 years.
The species is native to China and Japan
The tree is propagated by either direct sowing or planting out nursery raised seedlings. Seeds should be filed, soaked in cold water for 24 hours in dry weather or sown without soaking in wet weather. Germination in nursery beds commences within 10 days and is complete within 2-3 weeks. Without pretreatment, seeds sown in April and watered start germinating after 3 weeks and continue for 2-3 months, sometimes failing to germinate till the following year. Pretreatment either with concentrated sulphuric acid or cowdung slurry stimulates germination 21 days after sowing to 77-82 %, and has shown to be more effective than hot water treatment.
Poison: The fruit pulp is used in northern India and China to control head lice and as fish poison. Powdered seeds are insecticidal.
The tree has proved successful in the afforestation of eroded hill slopes at elevations below 900 m in the western Himalayas.
The seed kernel cake of S. Mukorossi contains 32 % crude protein and 7.9 % total N. The protein is mainly of the globulin type. Aspartic acid, glutamic acid, lysine, serine, glycine, arginine, alanine, valine, leucine/isoleucine, proline and tryptophan have been identified. However, the kennels lack about 44 % of essential amino acids and are thus inadequate for human nutrition but industrial protein could be prepared from the globulin fraction.
The leaves are used as fodder for cattle.
Apiculture: Honey water-white (also described as light golden), of mild flavour and good aroma.
The wood is used for charcoal production and as firewood.
Timber: The wood is light yellow, compact, close-grained and fairly hard, weighing 750 kg/m³ at 12 % moisture content.
Medicine: The fruit and seeds are regarded as a cure for epilepsy in northern India. A decoction of the fruit is used as an expectorant. Seeds are used in China to stop dental caries. The fruit is considered to be haemolytic.
Ornamental: S. mukorossi is cultivated throughout northern India as an ornamental.
Soil improver: Seed kernels which are a by-product of the oil extraction from the pericarp and shells can be used as fertilizer
Essential oil: Seeds contain 23 % oil of which 92 % is triglycerides; the triglyceride fraction contained 30 % oleo-palmito-arachidin glyceride, 13.3 % oleo-diarachidin glyceride and 56.7 % di-olein type glycerides such as dioleo-palmitin, dioleo-stearin
Pollution control: A surfactant obtained from the fruit pericarp of S. mukorossi has proved effective in the remediation of contaminated soils.