Tannot root is a root harvested by the Sykarans (among other races). Tannot roots are typically introduced to Peacekeeper-controlled worlds, and the roots themselves are processed as an integral component of Chakan oil, used to fuel PK weapons. The PKs usually force indigenous populations to grow the root, and once the root is harvested, the fields where it was grown are left unusable.
When ingested, the root causes the person eating it to exhibit strange, blissful behavior and renders the person extremely susceptible to commands. Knowing this, the Peacekeepers set up loudspeakers in the Sykaran settlement that continuously subjected the farmers to labor propaganda in addition to keeping the farmers on task and on schedule. However, if ingested by Hynerians it will make their bodily fluids explosive making even sweating and relieving oneself potentially deadly--their internal chemistry being similar to the process that makes chakan oil.
The tannot root's effects can be averted by the insertion of the rare Sykaran worm within the body, which consumes the toxins. A small percentage of individuals are naturally immune to the effect of the root. ("Thank God It's Friday... Again")