The term 'treelike cactus' refers to two species of cacti, the SAGUARO (7 letters) and the CHOLLA (6 letters). Both species are native to the deserts of the southwestern United States and northern Mexico. The SAGUARO is a large, columnar cactus that can grow up to 40 feet tall and live for over 200 years. The CHOLLA is a smaller, shrub-like cactus with cylindrical stems and spines. Both species are important to the ecology of the desert, providing food and shelter for many animals.