Ironweed

Ironweed is a type of plant, usually no thicker than a Human's arm, which contains mercury for sap.

On the planet Bliss, Prof. Shimura has bred a new variety of gigantic tree-sized Ironweeds. By feeding the Ironweeds' metallic sap to silkworms and combining the silkworms' genes with Piranha Locusts, Shimura also created a new species of metal-eating predators known as the Kiseibya.

Appearances

 * Big Finish Doctor Who audio stories, Enemy of the Daleks (2009)