Blue Myrtle Cactus (Myrtillocactus geometrizans) is a distinctive columnar cactus known for its smooth, waxy blue-green skin and branching candelabra-like form. Often referred to as Blue Candle Cactus or Bilberry Cactus, its sculptural ribs and upright growth make it a popular ornamental plant. Native to central and northern Mexico, it thrives in dry, rocky habitats and is well adapted to arid, high-elevation environments.

Small, star-like white to pale green flowers bloom along its ribs, followed by dark purple, edible fruits that resemble small berries—hence the name “myrtle” cactus. These fruits have traditionally been consumed by indigenous communities and are sometimes used in local sweets. The plant’s distinctive color and branching form are valued in landscape design for structure and contrast. Blue Myrtle Cactus also serves ecological roles, providing shelter and food for desert birds and insects. It is often used as grafting stock due to its hardy and fast-growing nature.