Hibiscus is a genus of the Malvaceae family of plants, which also include okra and cotton. There are no fewer than 200 species of Hibiscus, which grows in tropical climates. White Hibiscus is considered to have healing properties in Ayurvedic medicine, and natives of southern India have been using the red variety to degrease and protect their scalps for ages. And, of course, in Hawaii (where it's the state flower), it's also a popular hair accessory.*
In beauty products, Hibiscus is used to counteract oil on the skin. It's in Clarins Truly Matte Ultra-Matte Rebalancing Lotion for Oily Skin, Tarte Clean Slate Facial Primer, and Alba Botanical Hibiscus Facial Toner.
*Not just in Hawaii but all over the world, people are very passionate about Hibsicus. In fact, there is an International Hibiscus Society, the website of which includes videos, a Hibiscus jigsaw puzzle and a chat room. Yes.