Simmondsia chinensis (Link) Schneider = S. californica = Buxus chinensis
Fam Buxaceae
See also: Jojoba liquid wax - Jojoba oil in cosmetics
Description
Large dioecious shrub with a roundish shape, very long-lived (it lives up to 200 years).
It originates from America (there is no spontaneity in China, it was called " chinensis" due to a botanist's mistake).
Leaves: opposite, petiolate, entire margin, waxed green, cerulean green, then light green.
White flowers, pentamers, isolated and terminal, the male and female carried by different plants.
Fruit: an ovoid capsule containing 1-3 brown seeds, with large cotyledons.
Areal and culture
Native to Arizona and California, this plant was also known to the Aztecs who used it as food and oil, to treat skin diseases and wounds. It grows in several semi-arid regions of the world, where there is a fairly high temperature; Europe, Asia, Australia, Japan, North and South America. It lives on sandy or stony soil, poor and does not need fertilizers, it also requires little water. it adapts to extreme conditions thanks to the very developed and deep roots and the waxy coating of the leaves.
Used part 
The seeds are used, in particular the cotyledons, harvested at maturity in late summer. The cotyledons mainly contain wax-oily substances (44-64), from which the so-called jojoba liquid oil is obtained. There are also proteins (26-32%), carbohydrates (8%), fibers, and a cyanogenic glucoside, simmondsin. The oil is unusual: it lacks glycerin and there are unsaturated fatty acids at C30-C40 that form linear esters with monoethylene alcohols. This particular constitution is at the base of the particular properties of jojoba oil. This oil is in fact more fluid, stable, non-flammable and resistant to oxidation. It can polymerize in light and must therefore be stored in tin or dark glass bottles (such as olive oil).
uses
Multiple: due to the chemical-physical properties of the lipid constituents jojoba oil is used in the field:
therapeutic for the preparation of dermo-pharmaceutical emulsions with protective, nourishing, emollient and softening properties. In particular, sulfur oil is used to treat oily skin and acne.
The main sector of use is the cosmetic one, always in the dermatological field. Jojoba oil protects and lubricates skin and hair and is often used to prevent skin aging and the appearance of wrinkles.
The particular nature of the lipid constituents of jojoba oil allows on the one hand greater penetration and prompt epidermal absorption, on the other a high film-forming activity. It has a protective action even against the sun, due to the stability of these molecules to UV rays.
Jojoba oil and liquid wax, as well as being used in cosmetics, have various industrial uses : to make paints, detergents, resins and plastics and can be a substitute for whale fat used as a lubricant for precision engines.
