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Prunus dulcis - (Mill.)D.A.Webb.

Almond

Author	(Mill.)D.A.Webb.	Botanical references	11, 200
Family	Rosaceae	Genus	Prunus
Synonyms	Amygdalus communis - L. Amygdalus dulcis - Mill. Prunus amygdalus - Batsch. Prunus communis - L.
Known Hazards	Although no specific mention has been seen for this species, it belongs to a genus where most, if not all members of the genus produce hydrogen cyanide, a poison that gives almonds their characteristic flavour. This toxin is found mainly in the leaves and seed and is readily detected by its bitter taste. It is usually present in too small a quantity to do any harm but any very bitter seed or fruit should not be eaten. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death.
Range	Europe - E. Mediterranean to C. Asia.
Habitat	Cultivated ground, thickets, hedges and rocky places near cultivation[89].
Edibility Rating	3 (1-5)	Medicinal Rating	3 (1-5)

Physical Characteristics

A decidious Tree growing to 6m by 6m.

The plant prefers light (sandy), medium (loamy) and heavy (clay) soils and requires well-drained soil. The plant prefers acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It requires moist soil.

Habitats

Woodland Garden; Secondary; Sunny Edge; Dappled Shade; South Wall By; West Wall By;

Cultivars: (as above except)
'Largueta'
'Macrocarpa'
'Mission'

Edible Uses

Edible Parts: Seed.

Edible Uses: Gum; Milk; Oil.

Seed - raw, cooked or dried and ground into a powder for use in confections etc[7, 183]. The whole seed can also be roasted, sprouted or used in cakes, confectionery and pastry[183]. The sweet-flavoured forms have a delicious flavour but bitter forms should not be eaten in any quantity - see the notes above on toxicity. The seed is somewhat difficult to digest and so needs to be thoroughly masticated[4]. It can be blended with water to make almond milk[183]. An edible oil is obtained from the seed[183]. It is used mainly as a food flavouring and in cooking[57, 105]. An edible gum is obtained from points of damage on the stems[64].

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

Antitumor; Demulcent; Emollient; Nutritive; Pectoral.

As well as being a tasty addition to the diet, almonds are also beneficial to the overall health of the body, being used especially in the treatment of kidney stones, gallstones and constipation[238]. Externally, the oil is applied to dry skins and is also often used as a carrier oil in aromatherapy[238, K]. The seed is demulcent, emollient, laxative, nutritive and pectoral[4, 7, 21]. When used medicinally, the fixed oil from the seed is normally employed4]. The seed contains 'laetrile', a substance that has also been called vitamin B17[218]. This has been claimed to have a positive effect in the treatment of cancer, but there does not at present seem to be much evidence to support this[K]. The pure substance is almost harmless, but on hydrolysis it yields hydrocyanic acid, a very rapidly acting poison - it should thus be treated with caution[218]. In small amounts this exceedingly poisonous compound stimulates respiration, improves digestion and gives a sense of well-being[238]. The leaves are used in the treatment of diabetes[218]. The plant contains the antitumour compound taxifolin[218].

Other Uses

Adhesive; Cleanser; Cosmetic; Dye; Gum; Miscellany; Oil; Soap making.

An oil expressed from the seeds is an excellent lubricant in delicate mechanisms such as watches[4]. It is often used in soaps and cosmetics because it has a softening effect on the skin[4, 7]. A green dye can be obtained from the leaves[168]. A dark grey to green dye can be obtained from the fruit[168]. A yellow dye is obtained from the roots and leaves[148]. The bruised leaves, when rubbed within any container, will remove strong odours such as garlic or cloves so long as any grease has first been fully cleaned off[4]. A gum from the stems is used as an adhesive[64]. The burnt shell yields a valuable absorbent for coal gas[74]. The burnt pericarp is rich in potassium, it is used in soap making[74]. The seed contains amygdallin, under the influence of water and in the presence of emulsion it can be hydrolized to produce benzaldehyde (the almond aroma, formula C6 H5 CHO) and prussic acid (the toxic principle)[74].

Cultivation details

Thrives in a well-drained moisture-retentive loamy soil[11, 200]. Prefers some lime in the soil but is likely to become chlorotic if too much lime is present[1]. Succeeds in sun or partial shade though it fruits better in a sunny position[11, 200]. The almond is often cultivated in the temperate zone for its edible seeds, there are many named varieties[63, 200]. It prefers a Mediterranean climate with a clear distinction between winter and spring, in milder maritime areas it can be induced into flower too early in the season and is then very liable to be damaged by frosts[200]. There is also likely to be a shortage of pollinating insects around when the tree is in flower so hand pollination may improve the crop. Although partially self-fertile, better crops are obtained if at least 2 cultivars are grown[200]. There are two basic forms of almonds, one with bitter seeds and one with 'sweet' seeds. The bitterness is caused by the presence of hydrogen cyanide (see notes above). Although the bitter forms are used in making marzipan and as a food flavouring, the seeds themselves should not be eaten. Even the sweet forms should not be eaten in very large quantities. (Approximately 900 seeds at one time is considered to be a toxic dose for the average adult). Trees are hardier when grown on a plum rootstock[11]. Almond seedlings are the preferred rootstock when plants are grown on hot dry soils, peach rootstocks are better for heavier soils[200]. Trees are at least partially self-sterile. Most members of this genus are shallow-rooted and will produce suckers if the roots are damaged[238]. Plants in this genus are notably susceptible to honey fungus[200].

Propagation

Seed - requires 2 - 3 months cold stratification and is best sown in a cold frame as soon as it is ripe[200]. Sow stored seed in a cold frame as early in the year as possible[200]. Protect the seed from mice etc. The seed can be rather slow, sometimes taking 18 months to germinate[113]. Prick out the seedlings into individual pots when they are large enough to handle. Grow them on in a greenhouse or cold frame for their first winter and plant them out in late spring or early summer of the following year. Cuttings of half-ripe wood with a heel, July/August in a frame[11, 200]. Difficult. Softwood cuttings from strongly growing plants in spring to early summer in a frame[200]. Cuttings of mature wood, late autumn in a frame. Layering in spring.

Cultivars

'Largueta'

The large, long, juicy, sweet kernel averages 25 - 27% of the total nut weight[183]. Recommended for cold areas because the structure of the branches helps to protect the flowers from frost[183]. A drought and disease-resistant tree[183].

'Macrocarpa'

This form of P. dulcis has larger seeds than the type and easily cracked shells, it is often cultivated in the temperate zone for its edible seeds.

'Mission'

A round, hard-shelled nut with a slightly bitter flavour that is preferred by some[183]. The kernel averages 40 - 45% of the total weight of the nut[183]. Resistant to navel orange worm and bird damage[183]. A good tree for late frost areas because it blooms late[183]. It also ripens late, in late September to October[183]. This is the second most important cultivar in California, it pollinates with 'Nonpareil', 'Ne Plus Ultra' and 'Carmel'. It has a chilling requirement of 284 - 310 hours[183].

Links

This plant is also mentioned in the following PFAF articles: Edible Shrubs, Staple seed crops from perennials..

References

[K] Ken Fern
Notes from observations, tasting etc at Plants For A Future and on field trips.

[1] F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951
Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaces in 1992 by a new dictionary (see [200]).

[4] Grieve. A Modern Herbal. Penguin 1984 ISBN 0-14-046-440-9
Not so modern (1930's?) but lots of information, mainly temperate plants.

[7] Chiej. R. Encyclopaedia of Medicinal Plants. MacDonald 1984 ISBN 0-356-10541-5
Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.

[11] Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981
A classic with a wealth of information on the plants, but poor on pictures.

[21] Lust. J. The Herb Book. Bantam books 1983 ISBN 0-553-23827-2
Lots of information tightly crammed into a fairly small book.

[57] Schery. R. W. Plants for Man. 0
Fairly readable but not very comprehensive. Deals with plants from around the world.

[63] Howes. F. N. Nuts. Faber 1948
Rather old but still a masterpiece. Has sections on tropical and temperate plants with edible nuts plus a section on nut plants in Britain. Very readable.

[64] Howes. F. N. Vegetable Gums and Resins. Faber 0
A very good book dealing with the subject in a readable way.

[74] Komarov. V. L. Flora of the USSR. Israel Program for Scientific Translation 1968
An immense (25 or more large volumes) and not yet completed translation of the Russian flora. Full of information on plant uses and habitats but heavy going for casual readers.

[89] Polunin. O. and Huxley. A. Flowers of the Mediterranean. Hogarth Press 1987 ISBN 0-7012-0784-1
A very readable pocket flora that is well illustrated. Gives some information on plant uses.

[105] Tanaka. T. Tanaka's Cyclopaedia of Edible Plants of the World. Keigaku Publishing 1976
The most comprehensive guide to edible plants I've come across. Only the briefest entry for each species, though, and some of the entries are more than a little dubious. Not for the casual reader.

[113] Dirr. M. A. and Heuser. M. W. The Reference Manual of Woody Plant Propagation. Athens Ga. Varsity Press 1987 ISBN 0942375009
A very detailed book on propagating trees. Not for the casual reader.

[148] Niebuhr. A. D. Herbs of Greece. Herb Society of America. 1970
A pleasant little book about Greek herbs.

[168] Grae. I. Nature's Colors - Dyes from Plants. MacMillan Publishing Co. New York. 1974 ISBN 0-02-544950-8
A very good and readable book on dyeing.

[183] Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990 ISBN 0-9628087-0-9
Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.

[200] Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992 ISBN 0-333-47494-5
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.

[218] Duke. J. A. and Ayensu. E. S. Medicinal Plants of China Reference Publications, Inc. 1985 ISBN 0-917256-20-4
Details of over 1,200 medicinal plants of China and brief details of their uses. Often includes an analysis, or at least a list of constituents. Heavy going if you are not into the subject.

[238] Bown. D. Encyclopaedia of Herbs and their Uses. Dorling Kindersley, London. 1995 ISBN 0-7513-020-31
A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.

Readers Comments

Plants for a Future does not verify the accuracy of reader comments, use at your own risk. In particular Plants For A Future can not take any responsibility for any adverse effects from the use of plants. You should always consult a professional before using plants medicinally.

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