Ocimum basilicum

About 35 species of aromatic annuals, evergreen perennials and shrubs belong to this genus, which occurs in most warm and tropical regions, especially in Africa. All basils need ample warmth and light, and do not thrive outdoors in areas with cool summers. The most widely grown basil is Ocimum basilicum, a highly variable species in terms of both appearance and aroma. Purple-leafed variants, such as ‘Dark Opal’ and ‘Purple Ruffles’, are ornamental, and can be grown as container or bedding plants; they are also used for giving a purple tint to basil vinegar. Basils are rich in volatile oils, which often vary considerably within the same species and according to growing conditions. Some 20 or more constituents have been isolated, the main ones being methyl chavicol (anise), methyl cinnamate (cinnamon), eugenol (clove), citral (lemon), geraniol (rose), linalol (lilac/orange blossom), thymol (thyme), and camphor. Variants in which certain constituents predominate are known as chemotypes; O. americanum has three distinct chemotypes; floral-lemony, camphoraceous, and spicy. Its essential oil characteristically contains 70-88 percent methyl chavicol, an anise-scented compound, which in excess may be carcinogenic. The Mexican O. selloi (sometimes incorrectly given as O. sellowii) has an unusual scent resembling green peppers. In green peppers this characteristic aroma is due to pyrazines, which are difficul to detect in essential oil. Analysis of O. selloi shows that elemicin, methyl eugenol, alpha-copaene, and beta-caryophyllene predominate. The composition of oils in a particular plant affects its aroma, flavor and uses, though it may not differ in appearance from other plants of the same species. Mediterranean types of O. basillicum contain mainly linalol and methyl chavicol, with little or no camphor, which give the typical sweet basil flavor; E European types are characterized by methyl cinnamate; SE Asian types contain a high proportion of clove-scented eugenol; and, in Réunion or African types, camphor and methyl chavicol predominate. Hybridization in cultivation further complicates the picture. The most widely grown basils for commercial drying and oil extraction go under many different names, not necessarily recognized by botanists as distinct cultivars. Though mainly grown for their aromatic leaves, most basils also have seeds that are high in mucilage and have different uses from the foliage. Some basils are important in folklore and religion. The common name “basil” may be associated with the Basilisk (a mythical serpent-like creature whose glance and breath were fatal), as it was beleived that basil could turn into scorpions. Ocimum tenuiflorum, regarded in India as the most sacred plant after the Lotus (Nelumbo nucifera), is grown in most Hindu homes, and around temples, for its protective influence, holding basil root protects against thunder, and wearing a string of beads made from basil stems wards off infection and “induces religious tendency and longevity” (Indian Materia Medica, 1976). The tropical American duppy basil (O. campechianum syn. O. micranthum), also known as mosquito plant/bush or Peruvian basil, is crushed and hung in homes to repel mosquitoes; “duppy” is a word used in the Caribbean for a ghost or a mosquito. It also goes by the name “married man pork” and is used to flavor soups and stews. Ocimum is from the Greek okimon, used by Theophrastus for basil.

Today this savory herb is best known as a flavoring in spaghetti sauce, but well into the seventeenth century many believed that if you left a sprig of basil under a pot, in time it would turn into a scorpion. And smelling the herb would cause scorpions to nest in the brain!

Erect, much-branched, aromatic annual or short-lived perennial, woody at the base, with narrowly ovate to elliptic, entire or toothed, bright green leaves to 5cm (2in) long. Small, white, tubular flowers are borne in whorls to 2cm (¾in) apart.