flame maple top is grained maple wood, the grain has a pattern which resembles flames, there is nothin special about this, its only used for the asthetic and cosmetic purpose on guitar tops and other furniture (however some people say that it makes the sound brighter, but i dont think that it has a significant effect, any maple will do the same) other famous figured woods are, curly maple, burr maple, birds eye maple, quilt maple, koa, snake wood etc.
a ridiculously beautiful flame maple top: https://www.northridgehardwoods.com/Products/Private Stock/ps205.jpg droooooooooooooooooooooooooooooooooooooool