Tonguesbane

Tough, leafy plant growing around the Storm Gate. Named by a man who attempted to consume a leaf, losing his ability to taste (and spending days in debilitating pain) in the process. Slightly toxic. Common symptoms of consumption are dizziness, nausea, and inability to focus.
Can be brewed into a bitter drink that tends to be physically painful to consume due to extreme 'fizziness'. This concentrated tea can grant a level of storm affinity, generally manifesting as some form of lightning manipulation, if consumed often enough. The process also removes a significant portion of the toxins, filtering out all but the compounds necessary for gaining affinity.
In very small doses, can also be used to create an effect near identical to carbonation, making it a popular ingredient in some drinks. Cheaper drinks do not process the plant to remove toxins in order to save money in production.