red-hot poker

plural red-hot pokers

1. Many of the species of flowering plants of the genus Kniphofia, that produce an inflorescence in the form of a raceme of red flowers that turn yellow as they mature.

   1 more example

   1897 Sir Harry Johnston -- British Central Africa The Kniphofia (the “red-hot poker” of our gardens) is on the borderland between the grotesque and the beautiful. When its flower spike is in full bearing and the many little tube-like flowers are scarlet, lightening into yellow, it offers a fine body of colour; but without the bloom the plant with its limp attenuated leaves (green and spotted with white, having much of the aloe’s fleshiness without its pompous stiffness) looks like some monstrous caricature of a lily made in a madman’s world.

   Synonyms: brimstone flower

2. Used other than figuratively or idiomatically: see red-hot, poker.