Simmondsia chinensis (Link) C.K. Schneider
Family
Simmondsiaceae
Synonyms
Buxus chinensis Link, Simmondsia californica Nuttall.
Vernacular Names
|
English |
Jojoba, goat nut. |
|
Indonesia |
Jojoba. |
|
Philippines |
Jojoba. |
|
Thailand |
Jojoba. |
|
French |
Jojoba. |
Geographical Distributions
Simmondsia chinensis is native to the Sonora semi-desert in north-western Mexico and the south-western United States, but is thought to have originated near the Pacific coast in the Baja California peninsula, where the climate is milder and more even. The similarity of its oil to sperm whale oil was first discovered in 1933, and the later ban on the import of sperm whale oil into the United States in 1969 gave a big impetus to its development as an oil crop and its distribution outside its native habitat. Since the 1980s, its commercial production has spread to South and Central America, southern Africa, Australia and the Middle East. Experimental plantations have been made throughout the drier parts of the subtropics and tropics, including Indonesia and Malaysia.
Description
Simmondsia chinensis is an evergreen, dioecious, multi-stemmed and profusely branching shrub, erect in moist sites, and can grow up to 2-2.5(-6) m tall. In the desert sites, it is rounded semi-prostrate, measures 20-50 cm tall and the young parts are usually with soft hairs.
The leaves are thick and leathery, decussate and subsessile. The blade is ovate to elliptical, measuring 1.5-4 cm x 0.5-2 cm, with entire margin, and dull dark-green to grey-green but sometimes larger in female plants than in the male ones.
The inflorescence is an axillary, dense and rounded cluster of yellowish male flowers or an axil. The male flowers are about 6 mm long while the female ones are about 13 mm. The sepal is (4-)5(-6)-lobed. The male flowers are with irregular denticulate margin, while in the female flowers are with entire margin, accrescent, imbricate and persistent. The petal is absent. There are (8-)10(-12) stamens which are free, with short filaments, stout, with basifixed or sometimes ventrifixed anthers, conspicuously extrorse, 4-sporangiate, dehiscing via longitudinal slits, with 3-loculed pistil, 3 superior ovary and free styles.
The 1(-3)-seeded fruit is an ovoid capsule. The light brown to black seed is (the ‘nut’ in literature) ovoid and measures 1-1.5(-3) cm long. The cotyledons are thickened. The straight embryo is well-differentiated.
Ecology / Cultivation
The milder, open parts of the Sonora semi-desert form the natural habitat of Simmondsia chinensis. Its spread is restricted to the east by cool highlands, to the north-west by dense shrub vegetation and to the south by thorn forests. Its expansion into areas with a climate more favorable to plant growth seems limited by its susceptibility to grazing. In its natural habitat, it occurs from sea level up to 1500 m altitude, with annual rainfall of about 250 mm in coastal populations and 400 mm for inland populations and with average annual temperatures of 16-26°C. In inland sites with less than 300 mm rainfall, Simmondsia chinensis is only found along temporary watercourses or where run-off water collects. It is tolerant of extreme temperatures; mature plants may tolerate a minimum of -1°C and a maximum of 55°C. Frost damage is common in natural stands and is a major risk in cultivated plants. Seedlings are very susceptible to frost. The higher extreme temperatures have caused scorching of young twigs, leaves and fruits, but not death of plants. Simmondsia chinensis grows on well-drained, sandy, gravelly and neutral to slightly alkaline soils that are often rich in phosphorus. Some selections are tolerant of salinity; they grow and yield well in soils with electric conductivity of 38 dS/m or when irrigated with saline water of conductivity 7.3 dS/m. Cultivated Simmondsia chinensis is grown in areas with 300-750 mm rainfall. Rainfall higher than 750 mm is likely to increase the incidence of diseases.
Line Drawing / Photograph
References
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Plant Resources of South-East Asia No.14: Vegetable oils and fats.
