How does one disambiguate a subject so complex? Holy Basil, a plant that is gentle and healing to body, mind and spirit should bring happiness, not confusion! The commonality of all types (species/cultivars) is that the leaves may be eaten fresh, used in cooking, or best yet picked, dried, and made into tea.
Taxonomy: Vana Tulsi (a tree basil) is Ocimum gratissimum. The tropical tulsis (Rama, Krishna, Amrita, etc.) are Ocimum tenuiflorum which is the same as Ocimum sanctum (2 different Latin names used interchangeably). The temperate tulsi (formerly called “Kapoor” tulsi which is a misnomer and commonly called “Holy Basil” which is inaccurate but lovely) is classification unknown. Could it be Ocimum kilimandscharicum? Probably not, it smells like tutti-frutti, not camphor. However, a google search (odorless) would lead one to believe so!
Common names: The tropical basils intergrade (hybridize) freely, will vary in name and appearance depending on location and gardener, and have been called by many common names: Krishna Tulsi, Shyam Tulsi, Rama Tulsi, Amrita Tulsi, etc.
Pharmacology: For the purpose of identification, the presence of Eugenol (oil of clove) seems to be the ruling factor. All the tulsi types contain eugenol and smell and taste of clove. Eugenol is an antiseptic and is often used in dentistry. The anxiolytic (anti-anxiety) aspects of the herb have been attributed to the presence of Rosmarinic acid, which is present in varying concentration in all types of tulsi.
Comparative description of types of tulsi:
Vana Tulsi (Ocimum gratissimum) is a tree basil native to India and East Africa. The plant grows wild on roadsides and in waste places. The leaves are large and the plant can easily attain 5 feet tall, even when grown as an annual in the temperate north. Vana tulsi is relatively easy to overwinter indoors–they are very stable in a bright window, and once the soil warms outdoors, can be transplanted to the garden with good results. This type is often used as an ingredient in tulsi tea blends. There is a long history of misidentification–many products have used lemon basil and called it “vana” out of convenience. Here are the results of one of our analytical tests of Vana Tulsi: 8.89 Eugenol, 3.51 Rosmarinic Acid expressed as dried wt in mg/g.
Rama Tulsi (Ocimum tenuiflorum = O. sanctum) is a tropical perennial that may be grown as an annual in temperate gardens. The color of the leaves is primarily green, while the color of the stems is primarily purple. This is the most common type grown in India. Here are the results of one of our analytical tests of Rama Tulsi: 5.60 Eugenol, 5.15 Rosmarinic Acid expressed as dried wt in mg/g.
Krishna Tulsi (Ocimum tenuiflorum = O. sanctum) is a tropical perennial that may be grown as an annual in temperate gardens. The color of the leaves is green at first, but eventually develops to a mottled purple, while the color of the stems is primarily purple. This is a preferred type grown in India. Here are the results of one of our analytical tests of Krishna Tulsi: 4.90 Eugenol, 10.47 Rosmarinic Acid expressed as dried wt in mg/g.
Amrita Tulsi (Ocimum tenuiflorum = O. sanctum) was originally obtained from Amritapuri in Southern India. It is a Krishna Tulsi type, and as with any tulsi cultivar obtained from any particular place, it has its own uniaque characteristics. We have found this type to overwinter very nicely in a heated greenhouse (50 degrees F minimum temp). The plants tend to be globe-shaped, bushy and almost red when mature and flowering. I have heard that in India the plants grow very tall and are not globe shaped. Environment will have its influence!
Temperate Tulsi (AKA: “Holy Basil,” Latin unknown) was introduced by the now-defunct Abundant Life Seed Foundation. The plant has been grown successfully as a quick summer annual and is well-loved by American gardeners. The aroma is tutti-frutti, the plant bolts fast to flower, it magnetizes bees and is the only basil I know of that readily self-seeds from seed dropped the year before. To make the most of the leaf, it works best to direct-seed the plant in the spring garden and harvest on an ongoing basis, cutting back just prior to flowering. The plants are globe-shaped and do not get very tall–a foot or two at best. Careful management of the timing of planting and harvest can result in a good deal of dried tea from a few plants. This is the tea that we grow and dry for our own personal use, and it has been shown to be a healthy drink for our family. Here are the results of one of our analytical tests of Temperate Tulsi: 0.74 Eugenol, 5.53 Rosmarinic Acid expressed as dried wt in mg/g.
Here’s a video to show the differences between the several types of tulsi. I hope nobody gets too hung up about the different types–a tulsi by any other name would smell as sweet!