cereus

The term "cereus" refers to a genus of about 30 species of large, columnar cacti belonging to the family Cactaceae. These plants, native to South America, are characterized by their ribbed stems lined with areoles that bear stout spines. They produce large, fragrant, night-blooming white flowers and fleshy, often edible fruits.1

The name "cereus" is also broadly applied to other cacti with elongated bodies, often indicated by the suffix "-cereus" in their scientific names, such as Hylocereus and Selenicereus. Some well-known examples sometimes referred to as cereus include the saguaro and the organ pipe cactus. The genus Cephalocereus also includes large, columnar cacti, often topped with white wool. Cacti, in general, are adapted to arid environments, with most having succulent stems for photosynthesis and spines that are modified leaves to reduce water loss.123