Prionium serratum, the palmiet, is a robust, evergreen, semiaquatic, rhizomatous flowering plant growing to 2 m (6 ft 7 in) in height. It is the only species in the genus Prionium, and is endemic to South Africa (Cape Province and KwaZulu-Natal). Some authors have separated Prionium from the Thurniaceae, putting it instead in its own family, the Prioniaceae.