resin canal

A resin canal is a tubular space found in certain plants, specifically in gymnosperms and some angiosperms. These canals are lined with epithelial cells that secrete resin. Resin itself is an organic compound, either natural or synthetic, that exists as a noncrystalline or viscous liquid. Natural resins are typically yellowish to brown, transparent or translucent, and are formed from plant secretions, being soluble in organic liquids but not water. They are often exuded by trees, especially pines and firs, as a response to injury. While historically used in lacquers and varnishes, natural resins have largely been replaced by synthetic resins in modern industry.12