Time Tree

The Time Tree was a tree which enabled time travel simply by plucking its seeds, which grew into other time trees. However, the method of time travel was not exact: one seed could take someone back a thousand years, another ten thousand. They had an appetite for heavy metals and their leaves were orange. (PROSE: Genocide)

They originated on the planet Hirath, where they grew in heavy-metal rich soil. (PROSE: Longest Day)

The I left a time tree on the planet Tractis in one of their experiments. (PROSE: Seeing I) The Tractites attempted to change the history of Earth using this time tree. (PROSE: Genocide)