It's technically true that tea is only made from the camellia sinensis plant, but you can get the same experience from other "hot, tea-like drinks" as well such as Herbal and Rooibos "teas".

Please take a look at http://www.theteafinder.com. It's a tea search engine that I made after getting motivated reading HN a few weeks ago! You can search for tea by flavor and health benefit.

Would love feedback from other tea-drinking hackers.