Syferum

Syferum was a highly toxic nerve agent that was created from the oil extract of the Syferium plant, which occurred most commonly on Commenor.

Since its discovery, syferium plants were marked as illegal contraband under Republic/Imperial law, though many Commenorian farmers in league with the black markets continued to secretly cultivate the weaponized plant.

Description
Syferum was colorless, odorless, and had a slightly metallic taste, and would immediately begin released gaseous fumes when exposed to open air, requiring processed syferum to be contained in specialized canisters that rendered its contents fully air-tight until ready to be used. When ingested orally, syferum acted as a traditional poison and killed by causing rapid organ failure within minutes of ingestion; when ingested through respiration or intraveneous injection, syferum acted as a nerve agent - causing intense pain (followed by brief periods of complete numbness), hallucinations, delirium, and eventually death within an hour. In extremely small doses, Imperial Intelligence agents have purportedly used syferum as a truth serum, though its use in this field is unconfirmed. While syferum was extremely deadly, there have been many cases of Imperial soldiers surviving syferum attacks with little to no long-lasting effects. Strangely enough, the filtration system found in stormtrooper helmets - designed to filter out toxic substances even as undetectable as dioxis - were unable to filter out large amounts of syferum gas, forcing Imperial engineers to redesign the helmets' filtration devices to include syferum gas, which had seemingly become more popular on the battlefield.

Syferum was administered either by releasing the contents of its container into open air, detonating missiles/bombs equipped with syferum canisters, attacking a target with syferum darts, or "spiking" a targets beverage or meal with droplets of liquid syferum.

The syferium plant itself was almost entirely purple and, according to reports made by the Galactic Botanical Society, was ironically a close relative of the savorium plant, which was smoked in large quantities to produce psychoactive effects vaguely similar to that of cannabis.

History
Its properties as a chemical weapon were discovered during the Clone Wars, when several Separatist militias acquired syferum through the black markets and used syferum bombs extensively against Republic forces in some Outer Rim battles. A terrorist attack on Denon in 16 BBY also featured the use of syferum, in which a neo-Separatist terror cell used syferum to attack an Imperial military base, resulting in the death of more than 200 Imperial military personnel and dozens of their visiting family members during a ceremony. In the later years of the Mandalore campaign, an attack made on an Imperial outpost by Mandalorian insurgents involved the use of syferum canisters, killing more than a platoon of Imperial stormtroopers. Reports released by Rebel Alliance intelligence officers concluded that the Imperials themselves may have used syferum gas in some of their covert operations.