👉 Cork fluid, or phloem sap, is a viscous liquid found within the xylem and companion cells of cork oak (Quercus suber) trees, acting as a vital transport medium for water and nutrients. Unlike the rigid xylem vessels, cork fluid is less structured, flowing freely through the interconnected cells of the cork, facilitated by the presence of air-filled spaces and microscopic pores. This fluid is rich in sugars, amino acids, and other organic compounds, which are crucial for the tree's growth and defense mechanisms. The cork fluid also plays a role in the tree's ability to withstand environmental stresses, such as drought and fire, by maintaining cellular integrity and providing a barrier against pathogens.
