Which teas have the most caffeine can be very complicated to determine. With the camellia sinensis tea plant, there are many factors involved.
1. How much sun/shade the plant gets
2. The height of the plant
3. The age of the plant, and
4. How the leaves were processed.
If your tea has no true tea leaves in it, you’re actually drinking a tisane. Tisanes have no caffeine. If you are drinking a tea blended with fruits or herbs, the caffeine percentage will vary from cup to cup. Primarily the amount depends on the ratio of tea leaves to other ingredients.