A Decon III droid is shown here, tending to the kholm-grass.
Kholm-grass was a type of plant that originated on the planet known as Honoghr. Following the Battle of Honoghr, which occurred during the Clone Wars, the planet suffered immense damage, resulting in the widespread death of its native flora.
Darth Vader exploited this environmental disaster to keep the Noghri people enslaved for an extended period. He gained their favor by sending them supplies, but secretly replaced the original kholm-grass with a modified version that continued to poison the other indigenous plants. The decon droids supplied by the Empire were actually deployed to prolong the planet's economic hardship, removing the kholm-grass at the slowest rate possible. Although the Noghri noticed a change in the scent of the new kholm-grass, they wrongly attributed it to chemicals released by the Gahenna many years prior.
During the events of the Thrawn campaign, Leia Organa Solo and Chewbacca ultimately discovered the truth about the altered kholm-grass and revealed it to the Noghri. This revelation led them to leave the service of Grand Admiral Thrawn.