This document summarizes the common trees found in the forests of Catalonia, including the cork oak, deciduous oak, evergreen oak, and pine tree. It identifies the main parts of a tree, such as the crown, leaves, roots, seeds, and branches, and describes the key parts of a leaf, including the margin, petiole, main vein, and lateral veins. The document also briefly outlines the seasons and notes that in winter some trees lose their leaves while others remain evergreen.