Noughtweed

 was an extremely dangerous type of weed outlawed on every civilised world. The Thirteenth Doctor described it as "eating biological weapons for breakfast". It originated from the planet Gehenna Prime.

Renegade Gardeners used a modified variety of noughtweed to weaken the defences of and destroy the Galactic Seed Vault. In particular, they supplied it with a time propagator. (PROSE: The Secret in Vault 13)