The tree appears to be a native of western Asia, Barbary?, and Morocco; but it has been extensively distributed over the warm temperate regions of the Old World. It ripens its fruit in the south of England. It is a tree of moderate size; the leaves are lanceolate, and serrated at the edges; and it flowers early in spring. The fruit is a drupe, having a downy outer coat, called the epicarp, which encloses the reticulated hard stony shell, or "endocarp." The seed is the kernel which is contained within these coverings. The tree grows in Syria and Palestine; and is referred to in the Bible under the name of "Shaked", meaning "hasten." The word "Luz", which occurs in Genesis 30:37, and which some translations have as "hazel", is supposed to be another name for the almond. In Palestine the tree flowers in January. The application of "Shaked" or "hasten" to the almond is similar to the use of the name "May" for the hawthorn, which usually flowers in that month in Britain. The rod of Aaron, mentioned in Numbers 17, was taken from an almond tree; and the Jews still carry rods of almond blossom to the synagogues on great festival days. The fruit of the almond supplied a model for certain kinds of ornamental carved work (Exodus 25:33-34; 37:19-20).
There are two forms of the plant, the one (with pink flowers) producing sweet almonds, and the other (with white flowers) producing bitter almonds. The kernel of the former contains a fixed oil and emulsion. As late as the early 20th century it was used internally in medicine, with the stipulation that it must not be adulterated with the bitter almond; it remains fairly popular in alternative medicine but has fallen out of prescription among doctors.
The bitter almond is rather broader and shorter than the sweet almond, and contains about 50% of the fixed oil which also occurs in sweet almonds. It also contains a ferment emulsion which, in the presence of water, acts on a soluble glucoside?, amygdalin, yielding glucose, cyanide and the essential oil of bitter almonds or benzaldehyde. Bitter almonds may yield from 6 to 8% of prussic acid (also known as hydrogen cyanide). Extract of bitter almond was once used medicinally but even in small doses is severe and in larger doses can be deadly; the prussic acid must be removed before consumption.
"Oleum Amygdalae", the fixed oil, is prepared from either variety of almond and is a glyceryl oleate, with slight odour and a nutty taste. It is almost insoluble in alcohol but readily soluble in chloroform or ether. It may be used as a pleasant substitute for olive oil. The sweet almond itself contains practically no starch and may therefore be made into flour for cakes and biscuits for patients suffering from diabetes mellitus or any other form of glycosuria. Almond extract is also a popular substitute for vanilla extract among people with diabetes. Sweet almonds are used in marzipan, nougat, and macaroons, as well as other desserts. Almonds contain 35% USRDA [Vitamin E]? per ounce and are high in [monunsaturated fat]?, the "good" fat responsible for lowering [LDL cholesterol]?.
California has become the single largest producer of almonds since their introduction to the state in the mid 1700s; almonds now serve as California's seventh largest food export. Spain is the next largest producer of almonds after California, producing numerous commercial varieties of sweet almond, most notably the Jordan almond (imported from Malaga?) and the Valencia? almond.