Root ginger is ginger in its solid rhizome form, sold fresh or dried, the knobbly underground stem of the ginger plant. Fresh root ginger has a pungent, citrusy heat from gingerols, which mellow into sweeter, warmer shogaols when dried or cooked. It is grated, sliced, or juiced into curries, stir-fries, marinades, teas, and baking, and crystallised or ground versions extend its reach into confectionery. Medicinally it is best evidenced as an anti-nausea remedy, used for motion sickness and pregnancy sickness, and it carries anti-inflammatory interest. Fresh roots should feel firm and heavy; dried root, whether whole or powdered, keeps its potency for months in an airtight container away from light.