Ocimum tenuiflorum, commonly known as holy basil or tulsi, is a perennial aromatic herb in the mint family (Lamiaceae). The genus name Ocimum comes from the Greek ōkimon (“basil”), while the species epithet tenuiflorum means “slender-flowered” in Latin. The Sanskrit name Tulsi translates as “the incomparable one,” reflecting its revered cultural and spiritual significance in India. Native to the Indian subcontinent and Southeast Asia, it has been cultivated for over 3,000 years, revered as a sacred plant in Hinduism and Ayurveda, and is often grown in temple courtyards and household gardens. In antiquity, tulsi was described as a “rasayana” in Ayurvedic texts, credited with rejuvenating properties, and used in medicinal teas, poultices, and rituals for health and spiritual protection. It was historically administered for fevers, respiratory conditions, digestive ailments, and as a tonic for longevity.

In modern times, tulsi remains a cornerstone of Ayurvedic and Siddha medicine, widely consumed as tulsi tea, tinctures, powders, and extracts marketed globally as adaptogens for stress relief and immune support. In culinary traditions, tulsi is valued both as a medicinal herb and as a seasoning: in Thai cuisine, where it is known as kaphrao, it flavors stir-fries (pad kaphrao), soups, and curries. Its clove-like aroma, derived from eugenol and other volatile oils, distinguishes it from sweet basil (Ocimum basilicum). Today, tulsi is cultivated worldwide for herbal teas, supplements, essential oils, and culinary use.