The bay laurel (Laurus nobilis, of the plant family Lauraceae), also known as sweet bay, bay tree, true laurel, Grecian laurel,^[1] laurel tree, or simply laurel, is an aromatic evergreen tree or large shrub with green, glossy leaves, native to the Mediterranean region. It is the source of the bay leaf used in cooking. Under the simpler name "laurel," Laurus nobilis figures prominently in classical Greek, Roman, and Biblical culture.

Worldwide, many other kinds of plants in diverse families are also called "bay" or "laurel," generally due to similarity of foliage or aroma to Laurus nobilis, and the full name is used for the California bay laurel (Umbellularia), also in the family Lauraceae.

Characteristics

The laurel can vary greatly in size and height, sometimes reaching 10–18 metres (33–59 ft) tall. Laurus is a genus of evergreen trees belonging to the Laurel family, Lauraceae. The genus includes three species, whose diagnostic key characters often overlap (Mabberley 1997).

The laurel is dioecious (unisexual), with male and female flowers on separate plants.^[2] Each flower is pale yellow-green, about 1 cm diameter, and they are born in pairs beside a leaf. The leaves are 6–12 cm long and 2–4 cm broad, with a characteristic finely-serrated and wrinkled margin. The fruit is a small, shiny black berry about 1 cm long.^[2]

A laurel tree

Ecology

Laurus nobilis and Ilex aquifolium are widespread relics of the laurisilva forests that originally covered much of the Mediterranean Basin when the climate of the region was more humid. With the drying of the Mediterranean during the Pliocene era, the laurel forests gradually retreated, and were replaced by the more drought-tolerant sclerophyll plant communities familiar today. Most of the last remaining laurisilva forests around the Mediterranean are believed to have disappeared approximately ten thousand years ago at the end of the Pleistocene era, when the Mediterranean Basin became drier and with a harsher climate, although some remnants of the laurel forest flora still persist in the mountains of southern Turkey, northern Syria, southern Spain, north-central Portugal and northern Morocco. Indigenous laurisilva forest also persists in Madeira near the North Atlantic Ocean, which has moderated these climatic fluctuations.

The ecological requirements of the species, are those of the laurel forest and like most of their counterparts laurifolia in the world, it is vigorous species with a great ability to populate the habitat that is conducive. Laurus nobilis responded to favourable climatic periods and expanded across the available habitat. Laurus nobilis occur as opportunistic species across wide distribution with close relatives and few species, indicating the recent divergence of this species. The extant laurel species of this group are relatively young.

The laurus genus is characteristic of the formations of laurel forest and was more widespread in the Tertiary. It has led to endemic species on islands, but not so widespread geographically as in the past. The genus come from a few relict species living in temperate areas and more distributed in the Tertiary. The main centers are found inhabiting montane forests or coastal forest in low-altitude. Laurus nobilis species have adapted to more extreme conditions but mostly depending on favorable soil edaphic conditions, as presence of aquifers, groundwater periodic flows, etc.

The patterns of speciation in the Lauraceae family, where laurus genus belong, indicate that since the onset of aridification on the continents 15 million years ago, rainforest diversified in species numbers with the majority of species the product of vicariance. One of the products of aridification is the current island like archipelagos of rainforests along the planet. The fragmentation of once more continuous rainforest facilitated isolation of populations and this likely caused the increase in the rate of speciation as found in the Lauraceae. In Europe the genus is represented by a single species, the named Laurus nobilis. In macaronesian islands this former arose from a common ancestor in the area of laurisilva in the Mediterranean area. The islander laurels of Macaronesia in the eastern Atlantic, are closely related to this species. A recent study found that native stands classified as L. nobilis in northern Spain shared greater genetic and morphological similarity to L. azorica than to populations of L. nobilis native to rest of Spain, France and Italy [Arroyo-Garcia et al. 2001]. This populations like the Cortegada Island population, in Galicia, famous for its large grove of laurels, come from seeds dispersed by birds but is not indigenous to the island, as this islander forest originated spontaneously from laurel specimens that were planted after the original vegetation was destroyed.

Fossils dating from before the Pleistocene glaciations show that species of Laurus were formerly distributed more widely around the Mediterranean and North Africa, when the climate was more humid and mild than at present. It is currently thought that the drying of the Mediterranean basin during the glaciations caused Laurus to retreat to the mildest climate refuges, including southern Spain, Portugal and the Macaronesian islands. With the end of the last glacial period, L. nobilis recovered some of its former range around the Mediterranean.

Chemical constituents

The most abundant essential oil found in laurel is cineole, also called eucalyptol.^[2] The leaves contain about 1.3% essential oils (ol. lauri folii), consisting of 45% eucalyptol, 12% terpenes, 3-4% sesquiterpenes, 3% methyleugenol, and other α- und β-pinenes, phellandrene, linalool, geraniol, and terpineol.

Both essential and fatty oils are present in the fruit. The fruit is pressed and water-extracted to obtain these products. The fruit contains up to 30% fatty oils and about 1% essential oils (terpenes, sesquiterpenes, alcohols, and ketones).

Food

The plant is the source of several popular spices used in a wide variety of recipes, particularly among Mediterranean cuisines.^[2] Most commonly, the aromatic leaves are used, fresh or dried. For cooking purposes, whole bay leaves have a long shelf life of about one year, under normal temperature and humidity.^[3] Bay leaves are used almost exclusively as flavour agents during the food preparation stage; even when cooked, whole bay leaves can be sharp and abrasive enough to damage internal organs, so they are typically removed from dishes before serving, unless used as a simple garnish.^[3]

A laurel shrub

Ground bay leaves, however, can be ingested safely and are often used in soups and stocks, as well as being a common addition to a Bloody Mary.^[3] Dried laurel berries and pressed leaf oil can both be used as robust spices, and even the wood can be burnt for strong smoke flavouring.^[3]

Traditional medicine

Aqueous extracts of bay laurel can also be used as astringents and even as a reasonable salve for open wounds.^[4]

In massage therapy, the essential oil of bay laurel is reputed to alleviate arthritis and rheumatism, while in aromatherapy, it is used to treat earaches and high blood pressure.^{[5][unreliable source?]} A traditional folk remedy for rashes caused by poison ivy, poison oak, and stinging nettle is a poultice soaked in boiled bay leaves.^[6]

The chemical compound lauroside B isolated from Laurus nobilis is an inhibitor of human melanoma (skin cancer) cell proliferation at high concentrations.^[7]

Other uses

Laurel is widely cultivated as an ornamental plant in regions with Mediterranean or oceanic climates, and as a house plant or greenhouse plant in colder regions.

Laurel oil is a main ingredient, and the distinguishing characteristic of Aleppo soap. Aleppo soap is revered worldwide for its skin care properties.

Symbolism

Bay laurel was used to fashion the laurel wreath of ancient Greece, a symbol of highest status. A wreath of bay laurels was given as the prize at the Pythian Games because the games were in honor of Apollo, and the laurel was one of his symbols.

Ovid tells the story that laurel tree was first formed when the nymph Daphne was changed into a laurel tree because of Apollo's pursuit of her. Daphne is the Greek name for the tree.^[8]

The symbolism carried over to Roman culture, which held the laurel as a symbol of victory.^[9] It is also the source of the words baccalaureate and poet laureate, as well as the expressions "assume the laurel" and "resting on one's laurels".

In the Bible, the laurel is often an emblem of prosperity and fame. In Christian tradition, it symbolizes the resurrection of Christ.

In Chinese folklore, there is a great laurel tree on the moon, and the Chinese name for the laurel, (Chinese: 月桂), literally translates to "moon-laurel". This is the subject of a story of Wu Gang, a man who aspired to immortality and neglected his work. When the deities discovered this, they sentenced Wu Gang to fell the laurel tree, whereupon he could join the ranks of the deities; however, since the laurel regenerated immediately when cut, it could never be felled. The phrase (Chinese: 吴刚伐木) ("Wu Gang chops the tree") is sometimes used to refer to endless toil, analogous to the legend of Sisyphus in Greek mythology.

See also

• Cherry laurel
• California Bay Laurel
• Spotted laurel

Notes

References

• De Cleene, Marcel; Lejeune, Marie Claire (2003). Compendium of symbolic and ritual plants in Europe, Volume 1. Man & Culture. OCLC 482791069. 
• Green, Aliza (2006). Field Guide to Herbs & Spices. Philadelphia: Quirk Books. ISBN 1-59474-082-8. http://books.google.com/books?id=oGaF5FZ-sMMC&lpg=PA17&dq=bay%20laurel%20berries&pg=PA17#v=onepage&q=bay%20laurel%20berries&f=false. Retrieved 2010-12-31. 
• Nayak, S; Nalabothu, P; Sandiford, S; Bhogadi, V; Adogwa, A (2006). "Evaluation of wound healing activity of Allamanda cathartica. L. and Laurus nobilis. L. extracts on rats". BMC complementary and alternative medicine 6: 12. doi:10.1186/1472-6882-6-12. PMC 1456996. PMID 16597335. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1456996. 
• Wood, Jamie; Steinke, Lisa (2010). The Faerie's Guide to Green Magick from the Garden. New York: Random House. ISBN 1-58761-354-9. http://books.google.com/books?id=61Vm30HszfkC&lpg=PA43&dq=bay%20laurel&pg=PA43#v=onepage&q=bay%20laurel&f=false. Retrieved 2010-12-31. 
• Vaughan, John Griffith; Geissler, Catherine (2009). The New Oxford Book of Food Plants. Oxford: Oxford University Press. ISBN 0-19-954946-X. http://books.google.com/books?id=UdKxFcen8zgC&lpg=PA150&dq=bay%20laurel&pg=PA150#v=onepage&q=bay%20laurel&f=false. Retrieved 2010-12-31. 

Bay leaf (plural bay leaves) refers to the aromatic leaf of the bay laurel (Laurus nobilis, Lauraceae). Fresh or dried bay leaves are used in cooking for their distinctive flavor and fragrance. The leaves are often used to flavor soups, stews, braises and pâtés in Mediterranean cuisine. The fresh leaves are very mild and do not develop their full flavor until several weeks after picking and drying.^[1]

Taxonomy

The term "bay leaf" is used to refer to several other plants besides the leaves of L. nobilis. These include:

• California bay leaf – the leaf of the California bay tree (Umbellularia californica), also known as California laurel, Oregon myrtle, and pepperwood, is similar to the Mediterranean bay, but has a stronger flavor.
• Indian bay leaf or Malabathrum (Cinnamomum tejpata; also tej pat, tejpat, tejpata or palav aaku in Telugu or punnai ilai in Tamil or daalchini in Kannada), iin appearance to bay leaves, but is culinarily quite different, having a fragrance and taste similar to cinnamon (cassia) bark, but milder. In culinary terms, it is misleading to call it bay leaf because it is of a genus other than that of the bay laurel tree, it does not taste the same as the bay laurel leaf, and cannot be used in cooking as a substitute for the bay laurel leaf.
• Indonesian bay leaf or Indonesian laurel (salam leaf) – the leaf of Syzygium polyanthum is not commonly found outside of Indonesia; this herb is applied to meat and, less often vegetables. Like Indian bay leaf, it is also inaccurately named because the plant is actually a member of the Myrtaceae family.^[2]

History

The bay laurel tree has been cultivated since the beginning of recorded history;^[3] it originated in Asia Minor, and spread to the Mediterranean and other countries with suitable climates. Bay leaf is not grown in northern regions, as the plants do not thrive in cold climates. Turkey is one of the main exporters of bay leaves, although they are also grown in areas of Albania, France, Belgium, Italy, Russia, Central America, North America, and India.^[1] The laurel tree was very important both symbolically and literally in both Greece and Rome. The laurel can be found as a central component in many ancient mythologies that glorify the tree as a symbol of honor.^[4] Bay leaves are one of the most widely used culinary herbs in Europe and North America. In the Elizabethan era, some people believed pinning bay leaves to one's pillow on the eve of Saint Valentine's Day would permit one to see one's future spouse in a dream.

Taste and aroma

If eaten whole, bay leaves are pungent and have a sharp, bitter taste. As with many spices and flavorings, the fragrance of the bay leaf is more noticeable than its taste. When dried, the fragrance is herbal, slightly floral, and somewhat similar to oregano and thyme. Myrcene, which is a component of many essential oils used in perfumery, can be extracted from the bay leaf. They also contain the essential oil eugenol.^[4]

Uses

Bay leaves are a fixture in the cooking of many European cuisines (particularly those of the Mediterranean), as well as in North America. They are used in soups, stews, meat, seafood and vegetable dishes. The leaves also flavor many classic French dishes. The leaves are most often used whole (sometimes in a bouquet garni) and removed before serving (they can be abrasive in the digestive tract). In Indian (Sanskrit name tamaalpatra, Hindi tejpatta) and Pakistani cuisine, bay leaves are often used in biryani and other rich, spicy dishes - although not as an everyday ingredient in home cuisine - and as an ingredient in garam masala.

Bay leaves can also be crushed or ground before cooking. Crushed bay leaves impart more of their desired fragrance than whole leaves, but are more difficult to remove, and thus they are often used in a muslin bag or tea infuser. Ground bay laurel may be substituted for whole leaves, and does not need to be removed, but it is much stronger due to the increased surface area and in some dishes the texture may not be desirable.

Bay leaves can also be scattered in a pantry to repel meal moths,^[5] flies, roaches, and silverfish.

Bay leaves have been used in entomology as the active ingredient in killing jars. The crushed, fresh, young leaves are put into the jar under a layer of paper. The vapours they release kill insects slowly but effectively, and keep the specimens relaxed and easy to mount. The leaves discourage the growth of moulds. They are not effective for killing large beetles and similar specimens, but insects that have been killed in a cyanide killing jar can be transferred to a laurel jar to await mounting.^[6] It is not clear to what extent the effect is due to cyanide released by the crushed leaves, and to what extent other volatile products are responsible.

Medicinal value

This unreferenced section requires citations to ensure verifiability.

In the Middle Ages, bay leaves were believed to induce abortions and to have many magical qualities. They were once used to keep moths away, owing to the leaf's lauric acid content that gives it insecticidal properties. They have many properties that make them useful for treating high blood sugar, migraine headaches, bacterial and fungal infections, and gastric ulcers. Bay leaves and berries have been used for their astringent, carminative, diaphoretic, digestive, diuretic, emetic and stomachic properties. Bay oil, or oil of bays (oleum lauri) is used in liniments for bruises and sprains. Bay leaf has been used as an herbal remedy for headaches. It contains compounds, called parthenolides, which have proven useful in the treatment of migraines. Bay leaf has also been shown to help the body process insulin more efficiently, which leads to lower blood sugar levels, and to reduce the effects of stomach ulcers. Bay leaf contains eugenol, which has anti-inflammatory and antioxidant properties. Bay leaf is also an antifungal and antibacterial, and has also been used to treat rheumatism, amenorrhea, and colic.

Safety

Some members of the laurel family, as well as the unrelated, but visually similar mountain laurel and cherry laurel, have leaves that are poisonous to humans and livestock. While these plants are not sold anywhere for culinary use, their visual similarity to bay leaves has led to the oft-repeated belief bay leaves should be removed from food after cooking because they are poisonous. This is not true - bay leaves may be eaten without toxic effect. However, they remain very stiff even after thorough cooking, and if swallowed whole or in large pieces, they may pose a risk of scratching the digestive tract or even causing choking. Thus, most recipes that use bay leaves will recommend their removal after the cooking process has finished.^[7]

Cultivation

Gardeners in frost-free or light frost areas will find that bay laurel seedlings planted in the ground easily grow into large trees, 38 feet (12 m) and taller; but when kept pruned, it can thrive as a small bush. Bay laurel can also be grown in containers, the size of which limits the ultimate size of the trees. New plants are often started via layering, or from cuttings, since growing from seed can be difficult.

Bay trees are difficult to start from seed, due in part to the seed's low germination rate, and long germination period. Fresh seeds with the pericarp removed typically have a 40% germination rate, while dried seeds and/or seeds with an intact pericarp have yet lower germination rates. In addition, the seed germination period can be 50 days or more, which increases the risk of the seeds rotting before they germinate. Treating the seeds with gibberellic acid can be useful in increasing seed germination, as is careful monitoring of moisture levels in the rooting medium.^[8]

Gallery

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  Bay leaf

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  Leaves and flower buds

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  Bay leaves

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  Laurus nobilis bush

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  A closeup of several Laurus nobilis leaves

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  Dried bay leaves in a bowl

References

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