The Hylocereus undatus is a unique plant because it resembles a cactus with small spikes. It only looks like that; it is a touch-friendly plant and is therefore very popular. The Hylocereus produces numerous stems that can grow to 6-12 cm in length. As this plant matures, it can produce fruit. These fruits are called pitaya or dragon fruit. The stems are triangular and produce air roots by which they can climb trees. This plant is originally from Thailand.