The variegated shape of this plant presents 'spots' or shades of lighter color in the exact areas of the epidermis where there is a lack of chlorophyll. Such spots will never be identical in two different plants, thus making each specimen unique. In the normal form H. undulatus is a climbing cactus that uses its aerial roots to grow on rocks and trees, up to a height of ten meters. Its green stems are covered with numerous white areoles and small thin spines. It has an initially erect shape that tends to fall with growth. The flowering takes place from late spring to early summer, generating large white flowers with lime green basal petals, which bloom only at night. Its fruits, widely known as "dragon fruit" are edible, much sought after for their nourishing properties, in fact they are rich in fiber and vitamins.