There are several holy basil varieties, each with their own unique look, feel, taste and smell. What you may not know is that each of these plants is called tulsi, rather than holy basil by the people in which the country of origin reigns that each basil is from. English speakers have come to call it holy basil, but the name certainly applies because the plants are in fact seen as holy in the regions where they are from, so it is still appropriate, even if not entirely accurate. What you need to know about these plants is that each of them playes an important part in the big picture of Southeast Asian culture. When you have all of them brought together, you get a bigger general idea of what the culture is like that reveres these plants. Each has its own place in the history of that region and own story.
All of the holy basil varieties are in fact seen as holy and, as such, two of them are even named after gods. There is one variety of the holy basil that is named after the god Krishna. This variety of the holy plant is purple in color and has a very strong taste and huge medicinal properties that are widely taken advantage of everywhere it goes. It is a plant that has seen quite as much use in medicine as it has in cooking, as a matter of fact. One variety that is possibly used even more in cooking is the Rama version of the holy basil. This version is green, like the basil most of us know, and it has the holy basil benefits of a very pleasant perfume-like aroma that makes it the perfect incense or compliment to some foods.
Another widely known, but not as widely used variety of the holy basil is the Vana kind. This is not a gods name but rather a name that signifies that fact that this particular form of the basil grows wild, and is not used as much as the other two varieties are used. It is still revered as holy and, in fact, that is why it is allowed to grow wild as it is, so that people everywhere on their journeys or wherever they are can catch a glimpse of the wild vana holy basil and know that it belongs to the family of sacred plants that is very much respected in the regions where it grows like this, and thus is normally left to its own devices so as to facilitate more of its lore. That is what makes these plants this great.