The Almond (Prunus dulcis, syn. Prunus amygdalus Batsch., Amygdalus communis L., Amygdalus dulcis Mill.) is a species of tree of the genus Prunus, belonging to the subfamily Prunoideae of the family Rosaceae and native to the Middle East. Within Prunus, it is classified in the subgenus Amygdalus, distinguished from the other subgenera by the corrugated seed shell.

Almond is also the name of the edible and widely cultivated seed of this tree. Although popularly referred to as a nut, the almond seed or fruit is botanically not a true nut, but the seed of a drupe (a botanic name for a type of fruit).

Description

The almond is a small deciduous tree, growing to between 4 and 10 meters in height, with a trunk of up to 30 centimetres in diameter. The young shoots are green at first, becoming purplish where exposed to sunlight, then grey in their second year. The leaves are 1 cm long and 1.2–4 cm broad, with a serrated margin and a 2.5 cm petiole. The flowers are white or pale pink, 3–5 cm diameter with five petals, produced singly or in pairs before the leaves in early spring.

The fruit is a drupe 3.5–6 cm long, with a downy outer coat. The outer covering or exocarp, fleshy in other members of Prunus such as the plum and cherry, is instead a leathery grey-green coating called the hull, which contains inside a hard shell, and the edible seed, commonly called a nut in culinary terms. Generally, one seed is present, but occasionally there are two. In botanical terms, an almond is not a true nut. The reticulated hard woody shell (like the outside of a peach pit) surrounding the edible seed is called the endocarp. The fruit is mature in the autumn, 7–8 months after flowering.

Origin and history

The almond is a native to an area stretching from the northern Indian subcontinent westwards to Syria, Israel, and Turkey. It was spread by humans in ancient times along the shores of the Mediterranean into northern Africa and southern Europe and more recently transported to other parts of the world, notably California.

The wild form of domesticated almond grows in parts of the Levant; almonds must first have been taken into cultivation in this region. The fruit of the wild forms contains the glycoside amygdalin, "which becomes transformed into deadly prussic acid (hydrogen cyanide) after crushing, chewing, or any other injury to the seed." Before cultivation and domestication occurred, wild almonds were harvested as food and doubtless were processed by leaching or roasting to remove their toxicity.Fact: date=February 2008