[citation needed] The various basils have such distinct scents because the volatile aromatic compounds vary with cultivars.

[5] The essential oil from European basil contains high concentrations of linalool and methyl chavicol (estragole), in a ratio of about 3:1.

The exact taxonomy of basil is uncertain due to the immense number of cultivars, its ready polymorphy, and frequent cross-pollination (resulting in new hybrids) with other members of the genus Ocimum and within the species.

[21] 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.

[citation needed] 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.

UV-B increases the 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.

[citation needed] Basil suffers from several plant pathogens that can ruin the crop and reduce yield.

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 blanched quickly in boiling water.

[citation needed] The most commonly used Mediterranean basil cultivars are "Genovese", "Purple Ruffles", "Mammoth", "Cinnamon", "Lemon", "Globe", and "African Blue".

[citation needed] Lemon basil has a strong lemony smell and flavor due to the presence of citral.

[citation needed] When soaked in water, the seeds of several basil varieties become gelatinous, and are used in Asian drinks and desserts such as the Indian faluda, the Iranian sharbat-e-rihan, or hột é.

[citation needed] In Kashmir, the Ramadan fast is often broken with babre beole, a sharbat made with basil seeds.

[35] Studies of the essential oil have shown insecticidal and insect-repelling properties,[36] including potential toxicity to mosquitos.

[39] The pests Sitophilus oryzae, Stegobium paniceum, Tribolium castaneum, and Bruchus chinensis are evaluated by Deshpande et al. 1974 and '77.

[40] The essential oil of the leaf and terminal shoot is effective against a large number of bacterial species including Lactiplantibacillus plantarum and Pseudomonas spp.

[41] The essential oil of the leaf and terminal shoot is also effective against a large number of fungal species including Aspergillus spp., Candida spp., Mucor spp., and Geotrichum candidum.

[citation needed] Basil has religious significance in the Greek Orthodox Church, where it is used to sprinkle holy water.

[45] Some Greek Orthodox Christians avoid eating it due to its association with the legend of the Elevation of the Holy Cross.

[46] In Giovanni Boccaccio's 14th century Decameron, the fifth story of the narrative's fourth day involves a pot of basil as a central plot device.