Chasmanthe is a genus of flowering plants in the family Iridaceae, first described in 1932. It is endemic to South Africa where it is found in the Cape Province. It is widely grown as an ornamental and naturalized in various locations. In their native habitat the flowers are pollinated by sunbirds. The genus name is derived from the Greek words chasme, meaning “gaping”, and anthos, meaning “flower”.

Chasmanthe floribunda is a perennial cormous plant sprouting from a corm and producing clumps of long, narrow leaves. It erects one thin, tall stem which may approach a meter in height. Atop the stem is a spike inflorescence holding 20 to 40 flowers in neat vertical rows. The flower is a curving tube with a long upper lobe curving down over smaller lobes. From the mouth of the flower protrude the stamens with their large, hanging anthers, and the style. The flower is generally bright orange-red or scarlet on the upper lobe and yellow to orange in the lower lobes. There is a also a yellow flowering variety called Chasmanthe floribunda var ducketii.