Sabal causiarum, commonly known as the Puerto Rican Hat Palm or simply the Hat Palm, is a species of palm native to the Caribbean islands, particularly Puerto Rico and Hispaniola. It is a robust, slow-growing palm that can reach heights of up to 50 feet, with a trunk diameter of up to 2 feet. The palm is known for its large, fan-shaped leaves that can reach lengths of up to 10 feet, giving it a distinctive, tropical appearance.