This is Dracaena draco, also known as Canary Islands Dragon Tree. These interesting and unusual trees are drought tolerant and can be planted in full sun. When young, this plant is a single stalk. At 10 or 15 years the stem stops growing and the plant forms a flower spike which is loaded with white lily like flowers that have a wonderful perfumed fragrance. The flowers are followed by coral berries and then a crown of buds forms and then the plant starts branching. Each branch grows another 10 to 15 years before branching off again. As the slow growing tree gets taller and older it develops an umbrella shape. USDA Hardiness Zones 9b to 11