Ocimum tenuiflorum (holy basil)
Holy basil is an important medicinal and religious plant closely related to the basil we use for cooking.
Ocimum tenuiflorum (Photo: GourangaUK)
Applications to the skin can cause reactions in sensitive people.
About this species
Ocimum tenuiflorum is closely related to culinary basil (Ocimum basilicum), but differs in being a short-lived perennial with smaller flowers. Commonly known as holy basil or tulsi and tulasi in South Asia, it is an important sacred plant in Hinduism and, as with many plant species used in Asia, the religious uses are often linked with the medicinal uses. Historically, holy basil was frequently grown in large vessels in the courtyards of Hindu forts and temples to cleanse the body. One of the plant’s synonyms, Ocimum sanctum, reflects this religious connection.
Geography and distribution
Native to tropical and subtropical Asia, and cultivated and naturalised in other tropical areas.
Holy basil is an aromatic, perennial herb up to 1 m tall, sometimes purplish in colour. The leaves are elliptic (narrow oval) in shape. The fruits have four small brown nutlets, which, unlike basil, do not produce a lot of mucilage when wet.
Regarded as sacred in Hinduism, Ocimum tenuiflorum has many traditional medicinal uses. A mixture of leaves and seeds, with black pepper (Piper nigrum) is given to pregnant women suffering from malaria. Fresh flowers are used to treat coughs and colds. The plant has shown promise in clinical trials in alleviating hepatic dysfunction, and is an ingredient of pills and ointment to cure eczema. The essential oil from some populations of holy basil contains high levels of eugenol. In traditional Thai medicine, the leaf or whole plant is used to alleviate nausea, vomiting, diarrhoea and flatulence. Alcohol extracts from the plant heal peptic ulcers.
The leaf extract is effective in checking the spread of the fungal pathogens Pyricularia oryzae and Rhizoctonia solani, which cause blast disease and sheath blight disease of rice. Antibacterial activity and deterrent against the larvae of root knot nematode (Meloidogyne incognita) have been reported, and the oil is a mosquito repellent.
Ocimum tenuiflorum is used as a major flavouring ingredient in Thai cuisine. Because it is regarded as sacred in Hinduism, it is used to make rosaries - the woody stems are used to make the beads.
Millennium Seed Bank: Seed storage
Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
Number of seed collections stored in the Millennium Seed Bank: One
Germination testing: Successful
A native of South Asia, it can be grown in pots in the UK, but is not frost-hardy.
Mabberley, D.J. (2008). Mabberley’s Plant-Book: A Portable Dictionary of Plants, their Classification and Uses, 3rd Ed. Cambridge University Press.
National Institute of Science Communication and Information Resources (CSIR) (2003). The wealth of India: a dictionary of Indian raw materials and industrial products. First Supplement Series (Raw Materials), Vol. 4: J-Q. CSIR, New Delhi.
Promjit Saralamp, Wongsatit Chuakul, Rungravi Temsiririrkkul & Clayton, T. (1996). Medicinal Plants in Thailand Vol. 1. Dept. of Pharmaceutical Botany, Mahidol University, Bangkok.
Kew Science Editor: Alan Paton
Kew contributors: Sustainable Uses Group
Copy editing: Kew Publishing
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