Basil (, ; ''Ocimum basilicum'' , also called great basil, is a culinary herb of the Family (biology), family Lamiaceae (mints). It is a Hardiness (plants), tender plant, and is used in cuisines worldwide. In Western cuisine, the generic term "basil" refers to the Variety (botany), variety also known as sweet basil or Genovese basil. Basil is native to tropical regions from Central Africa to Southeast Asia. In temperate climates basil is treated as an annual plant, however, basil can be grown as a short-lived Perennial plant, perennial or Biennial plant, biennial in warmer Hardiness zone, horticultural zones with Tropical climate, tropical or Mediterranean climates. There are many List of basil cultivars, varieties of basil including sweet basil, Thai basil (''O. basilicum'' var. ''thyrsiflora''), and Mrs. Burns' Lemon basil, Mrs. Burns' Lemon (''O. basilicum var. citriodora''). ''O. basilicum'' can Cross-pollination, cross-pollinate with other species of the ''Ocimum'' genus, producing Hybrid (biology), hybrids such as lemon basil (''O. × citriodorum'') and African blue basil (''O. × kilimandscharicum'').

Etymology

The name "basil" comes from the Latin , and the Greek language, Greek (), meaning "royal/kingly plant", possibly because the plant was believed to have been used in production of royal perfumes. Basil is likewise sometimes referred to in French language, French as ('the royal herb'). The Latin name has been confused with basilisk, as it was supposed to be an antidote to the basilisk's venom.

Description

Basil is an annual, or sometimes perennial, herb used for its leaves. Depending on the variety, plants can reach heights of between . Its leaves are richly green and ovate, but otherwise come in a wide variety of sizes and shapes depending on cultivar. Leaf sizes range from long, and between wide. Basil grows a thick, central taproot. Its flowers are small and white, and grow from a central inflorescence, or Raceme#Spike, spike, that emerges from the central stem atop the plant. Unusual among Lamiaceae, the four stamens and the pistil are not pushed under the upper lip of the Corolla (flower), corolla, but lie over the inferior lip. After entomophily, entomophilous pollination, the corolla falls off and four round achenes develop inside the bilabiate calyx (botany), calyx.

Phytochemistry

The various basils have such distinct scents because the volatile organic compound, volatile aromatic compounds vary with cultivars. The essential oil from European basil contains high concentrations of linalool and methyl chavicol (estragole), in a ratio of about 3:1. Other constituents include: 1,8-cineole, eugenol, and myrcene, among others. The clove scent of sweet basil is derived from eugenol. The aroma profile of basil includes 1,8-cineole and methyl eugenol. In this species eugenol is Isoeugenol synthase, synthesised from coniferyl acetate and Nicotinamide adenine dinucleotide phosphate, NADPH. Some of these are useful as insect repellents, see below.

Distribution and habitat

Basil is native to India and other tropical regions stretching from Africa to South East Asia, but has now become globalized due to human cultivation.

Taxonomy

The exact taxonomy of basil is uncertain due to the immense number of cultivars, its ready Polymorphism (biology), polymorphy, and frequent cross-pollination (resulting in new hybrids) with other members of the genus ''Ocimum'' and within the species. ''Ocimum basilicum'' has at least 60 varieties, which further complicates taxonomy.

Cultivars

Most basils are cultivars of sweet basil. Most basil varieties have green leaves, but a few are purple, such as, 'Purple Delight'. * Anise basil, Licorice basil, or Persian basil (''O. basilicum'' 'Liquorice') * Cinnamon basil (''Ocimum basilicum'' 'Cinnamon') * Dark opal basil (''Ocimum basilicum'' 'Dark Opal') * Spicy globe basil, Globe basil, dwarf basil, French basil (''Ocimum basilicum'' 'Minimum') * Lettuce leaf basil (''Ocimum basilicum'' 'Crispum') * Purple basil (''Ocimum basilicum'' 'Purpurescens') * Red rubin basil, Rubin basil (''Ocimum basilicum'' 'Rubin') * Thai basil (''Ocimum basilicum thyrsifolium'')

Hybrids

* African blue basil (''Ocimum basilicum × O. kilimandscharicum'') * Lemon basil (''Ocimum basilicum × O. americanum'') * Spice basil (''Ocimum basilicum × O. americanum''), which is sometimes sold as holy basil * Greek basil (''Ocimum basilicum var. minimum'')

Similar species

Some similar species in the same genus may be commonly called "basil", although they are not Variety (botany), varieties of ''Ocimum basilicum''. * Camphor basil, African basil (''Ocimum kilimandscharicum, O. kilimandscharicum'') * Clove basil, also African basil (''Ocimum gratissimum'') * Holy basil (''Ocimum tenuiflorum'', formerly known as ''O. sanctum'')

Cultivation

Growing conditions

Basil is sensitive to cold, with best growth in hot, dry conditions. It behaves as an annual if there is any chance of a frost. However, due to its popularity, basil is cultivated in many countries around the world. Production areas include countries in the Mediterranean area, those in the temperate zone, and others in subtropical climates. In Northern Europe, Canada, the northern states of the U.S., and the South Island of New Zealand, basil grows best if sown under glass in a peat pot, then planted out in late spring/early summer (when there is little chance of a frost); however, it can also thrive when planted outside in these climates. Additionally, it may be sown in soil once chance of frost is past. It fares best in well-drained soil with direct exposure to the sun. Although basil grows best outdoors, it can be grown indoors in a pot and, like most herbs, will do best on a sun-facing windowsill, kept away from extremely cold drafts. A greenhouse or row cover is ideal if available. It can, however, even be grown in a basement under fluorescent lights. Supplemental lighting produces greater biomass and phenol production, with red + blue specifically increasing growth and flower bud production. UV-B increases the volatile organic compound, volatiles in ''O. basilicum'' essential oil, which has not been reproducible in other plants, and so may be unique to the genus or even to this species. Basil plants require regular watering, but not as much attention as is needed in other climates. If its leaves have wilted from lack of water, it will recover if watered thoroughly and placed in a sunny location. Yellow leaves towards the bottom of the plant are an indication that the plant has been stressed; usually this means that it needs less water, or less or more fertilizer. Basil can be propagated reliably from cuttings with the stems of short cuttings suspended in water for two weeks or until roots develop.

Pruning, flowering, and seeding

Once a stem produces flowers, foliage production stops on that stem, the stem becomes woody, and essential oil production declines. To prevent this, a basil-grower may pinch off any flower stems before they are fully mature. Because only the blooming stem is so affected, some stems can be pinched for leaf production, while others are left to bloom for decoration or seeds. Picking the leaves off the plant helps promote growth, largely because the plant responds by converting pairs of leaflets next to the topmost leaves into new stems. Once the plant is allowed to flower, it may produce seed pods containing small black seeds, which can be saved and planted the following year. If allowed to go to seed, a basil plant will grow back the next year.

Diseases

Basil suffers from several plant pathogens that can ruin the crop and reduce crop yield, yield. Fusarium wilt is a soil-borne fungal disease that will quickly kill younger basil plants. Seedlings may be killed by ''Pythium'' damping off. A common foliage, foliar disease of basil is gray mold caused by ''Botrytis cinerea''; it can cause infections post-harvest and is capable of killing the entire plant. Black Spot (disease), Black spot can be seen on basil foliage and is caused by the fungi genus ''Colletotrichum''. Downy mildew caused by ''Peronospora belbahrii'' is a significant disease, as first reported in Italy in 2004. It was reported in the U.S. in 2007 and 2008. Non-pathogenic bacteria found on basil include ''Novosphingobium'' species.

Uses

Culinary

Basil is most commonly used fresh in recipes. In general, it is added last, as cooking quickly destroys the flavor. The fresh herb can be kept for a short time in plastic bags in the refrigerator, or for a longer period in the freezer, after being blanching (cooking), blanched quickly in boiling water.

Leaves and flowers

The most commonly used Mediterranean basil cultivars are "Genovese", "Purple Ruffles", "Mammoth", "Cinnamon", "Lemon", "Globe", and "African Blue basil, African Blue". Basil is one of the main ingredients in pesto, an Italian cuisine, Italian sauce with olive oil and basil as its primary ingredients. Many national cuisines use fresh or dried basils in soups and other foods, such as to thicken soups. Basil is commonly steeped in cream or milk to create flavor in ice cream or chocolate truffles. Lemon basil has a strong lemony smell and flavor due to the presence of citral. It is widely used in Indonesian cuisine, Indonesia, where it is called and served raw as an accompaniment to meat or fish.

Seeds

When soaked in water, the seeds of several basil varieties hydrophile, become gelatinous, and are used in Asian drinks and desserts such as the Indian cuisine, Indian ''faluda'', the Iranian cuisine, Iranian , or . In Kashmir, the Ramadan fast is often broken with ''babre beole'', a sharbat made with basil seeds.

Folk medicine

Basil is used in traditional medicine, folk medicine practices, such as those of Ayurveda or traditional Chinese medicine.

Toxicity to pests and pathogens

Insecticide and insect repellent

Studies of the essential oil have shown Insecticide, insecticidal and Insect repellent, insect-repelling properties, including potential toxicity to mosquitos. The essential oil is found by Huignard et al. 2008 to inhibit electrical activity by decreasing action potential amplitude, by shortening the post hyperpolarization (biology), hyperpolarization phase, and reducing the action frequency of action potentials. In Huignard's opinion this is due to the linalool and estagole, the amplitude reduction due to linalool, and the phase shortening due to both. ''Callosobruchus maculatus'', a pest which affects cowpea, is repelled by the essential oil. The essential oil mixed with kaolin is both an adulticide and an ovicide (insecticide), ovicide, effective for three months in against ''C. maculatus'' in cowpea. The thrips ''Frankliniella occidentalis'' and ''Thrips tabaci'' are repelled by ''O. basilicum'', making this useful as an insect repellent in other crops. The pests ''Sitophilus oryzae'', ''Stegobium paniceum'', ''Tribolium castaneum'', and ''Bruchus chinensis'' are evaluated by Deshpande et al. 1974 and '77.

Nematicide

The essential oil is found by Malik et al. 1987 and Sangwan et al. 1990 to be nematicide, nematicidal against ''Tylenchulus semipenetrans'', ''Meloidogyne javanica'', ''Anguina tritici'', and ''Heterodera cajani''.

Bacterial and fungal inhibition

The essential oil of the leaf and/or terminal shoot is effective against a large number of bacterial species including ''Lactiplantibacillus plantarum'' and ''Pseudomonas'' spp. The essential oil of leaf and/or terminal shoot is also effective against a large number of fungal species including ''Aspergillus'' spp., ''Candida (fungus), Candida'' spp., ''Mucor'' spp., and ''Geotrichum candidum''.

Culture

There are many rituals and beliefs associated with basil. The ancient Egyptians and ancient Greeks believed basil would open the gates of heaven for a person passing on. Jewish folklore suggests it adds strength while fasting. However, Herbalist Nicholas Culpeper saw basil as a plant of dread and suspicion. In Portugal, dwarf bush basil is traditionally presented in a pot, together with a poem and a paper carnation, to a sweetheart, on the religious holidays of John the Baptist (see ) and Saint Anthony of Padua. In Giovanni Boccaccio's 14th century The Decameron, ''Decameron'', the fifth story of the narrative's Summary of Decameron tales#Fourth day, fourth day involves a pot of basil as a central plot device. This famous story inspired John Keats to write his 1814 poem "Isabella, or the Pot of Basil", which was in turn the inspiration for two paintings of the Pre-Raphaelite Brotherhood: John Everett Millais's Isabella (Millais painting), ''Isabella'' in 1849 and in 1868 the ''Isabella and the Pot of Basil'' by William Holman Hunt. Basil has religious significance in the Greek Orthodox Church, where it is used to sprinkle holy water. The Bulgarian Orthodox Church, Serbian Orthodox Church, Macedonian Orthodox Church and Romanian Orthodox Church use basil ( bg, босилек, ; sr, босиљак, ; mk, босилек, ) to prepare holy water and pots of basil are often placed below church altars. Some Greek Orthodox Christians even avoid eating it due to its association with the legend of the Elevation of the Holy Cross.

References

External links

Basil: Knowing and Growing from the New York Botanical Garden
{{sister bar, auto=yes, commons=Ocimum basilicum, wikt=basil Articles containing video clips Flora of Asia Flora of New Guinea Herbs Indian spices Insect repellents Mediterranean cuisine Medicinal plants of Asia Ocimum Taxa named by Carl Linnaeus