Kava by Rex Tongan Pride is generally lanu-mata which literally means "green" in Tongan. We also periodically have what they call 'uli 'uli or "black" kava. All of our Tongan kava is grown on the main island of Vava'u which is well known to be the best island to grow kava on due to the rich volcanic soil.
Our people in Tonga do not use any actual cultivar names and just say if it is simply either a black or green variety, short or tall and if the powder is either light or dark colored.
