Ocimum tenuiflorum
Ocimum tenuiflorum, commonly known as holy basil, tulsi or tulasi, and tamole, damole, or domole in Fiji, is an aromatic perennial plant in the family Lamiaceae. It is native to tropical and subtropical regions of Australia, Malesia, Asia, and the western Pacific. It is widely cultivated throughout the Southeast Asian tropics. This plant has  escaped from cultivation and has naturalized in many tropical regions of the Americas. It is an agricultural and environmental weed.

Tulsi is cultivated for religious and traditional medicine purposes, and also for its essential oil. It is widely used as a herbal tea, commonly used in Ayurveda, and has a place within the Vaishnava tradition of Hinduism, in which devotees perform worship involving holy basil plants or leaves.

Morphology

Holy basil is an erect, many-branched subshrub,  tall with hairy stems. Leaves are green or purple; they are simple, petioled, with an ovate blade up to  long, which usually has a slightly toothed margin; they are strongly scented and have a decussate phyllotaxy. The purplish flowers are placed in close whorls on elongated racemes.

The three main morphotypes cultivated in India and Nepal are Ram tulsi (the most common type, with broad bright green leaves that are slightly sweet), the less common purplish green-leaved (Krishna or Shyam tulsi) and the common wild vana tulsi (e.g., Ocimum gratissimum).

Phytochemicals 
The plant and its oil contain diverse phytochemicals, including tannins, flavonoids, eugenol, caryophyllenes, carvacrol, linalool, camphor, and cinnamyl acetate, among others. One study reported that the plant contains an eponymous family of 10 neolignan compounds called tulsinol A-J. 

Specific aroma compounds in the essential oil are camphor (32%), eucalyptol (19%), ⍺-bisabolene (17%), eugenol (14%), germacrene (11%) and β-bisabolene (11%). In addition, more than 60 different aroma compounds were found through gas chromatography–mass spectrometry analysis of holy basil. However, other studies have stated tulsi essential oil consists mostly of eugenol (70%) β-elemene (11%), β-caryophyllene (8%), and germacrene (2%), with the balance being made up of various trace compounds, mostly terpenes.

Uses

Culinary
Tulsi (Sanskrit: Surasa) has been used in Ayurvedic and Siddha practices for its supposed medicinal properties.

Thai cuisine
 
The leaves of holy basil, known as kaphrao in the Thai language (), are commonly used in Thai cuisine for certain stir-fries and curries such as phat kaphrao () — a stir-fry of Thai holy basil with meats, seafood or, as in khao phat kraphao, with rice. Two different types of holy basil are used in Thailand, a "red" variant which tends to be more pungent, and a "white" version for seafood dishes. Kaphrao should not be confused with horapha (), which is normally known as Thai basil, or with Thai lemon basil (maenglak; ).

Insect repellent
For centuries, the dried leaves have been mixed with stored grains to repel insects.

Nematicidal
The essential oil may have nematicidal properties against Tylenchulus semipenetrans, Meloidogyne javanica, Anguina tritici, and Heterodera cajani.

Disinfection
Water disinfection using O. tenuiflorum extracts was tested by Bhattacharjee et al 2013 and Sadul et al 2009. Both found an alcoholic extract to be more effective than aqueous or leaf juice. Sundaramurthi et al 2012 finds the result to be safe to drink and antimicrobial. A constituent analysis by Sadul found alkaloids, steroids, and tannins in the aqueous, and alkaloids and steroids only in the alcoholic extract.

Significance in Hinduism

Tulsi is a sacred plant for Hindus, particularly the Vaishnavite sect. It is worshipped as the avatar of Lakshmi, and is often planted in courtyards of Hindu houses or temples to Hanuman. The ritual lighting of lamps each evening during Karthik includes the worship of the tulsi plant. Vaishnavites are also known as "those who bear the tulsi around the neck".

Tulsi Vivah is a ceremonial festival performed between Prabodhini Ekadashi (the 11th or 12th lunar day of the bright fortnight of the Hindu month of Kartik) and Kartik Purnima (the full moon of the month).

Every evening, Bengali Hindus place earthen lamps in front of tulsi plants. During the Kati Bihu festival celebrated in Assam, people light earthen lamps (diya) at the foot of the household tulsi plants and pray.

Gallery

See also
 Sacred trees
 Sacred groves

References

External links

Herbs
tenuiflorum
Flora of tropical Asia
Plants described in 1753
Indian spices
Taxa named by Carl Linnaeus