Prionium
Prionium is a monotypic genus. Prionium is a robust, evergreen, semiaquatic, rhizomatous flowering plant growing to 2 m in height. The stem of P. serratum is up to 10 cm in diameter and covered with the black, fibrous bases of old spirally arranged leaves, four-ranked or tristichous. The strap-like lanceolate leaves are rigid, narrow, leathery, grey-green, and with toothed margins. The small, brown flowers are on a branched inflorescence. Plants are hermaphroditic and pollination is anemophilous. The fruit is a dry dehiscent triangular capsule, with three seed chambers and arillate seeds which are hispid (with sclerenchymatous fibres) and winged. The net-like, black fibrous, reticulate leaf sheaths are often found on beaches near rivers with colonies of palmiet. New flower shoots are cooked as vegetables. Prionium is endemic to South Africa.