Weirwood is a fictional tree species from the A Song of Ice and Fire series by George R.R. Martin. These trees are characterized by their white bark and red leaves, often featuring faces carved into their trunks. Weirwoods are sacred to the Children of the Forest and the Old Gods of the Forest, playing a significant role in the spiritual practices of the North. In the story, weirwoods are often found in sacred groves and are used for worship and communication with the divine. Their sap is known to have mystical properties, and the trees are linked to the ancient history of the Seven Kingdoms.