In the wild, the Myrtillocactus species are widespread in Mexico including the Baja California peninsula. There are four species of Myrtillocactus which are recognized and unlike most other genera belonging to the Cactaceae family, the taxonomy of Myrtillocactus is quite settled and universally accepted. The four species are all similar in that they are shrub or tree-like, much-branching plants with four to eight prominent ribs. Typically the ribs features a single, thick, long central spine and only a few thick, short radial spines or the areoles may be spineless. Flowers are quite small at less than 2.5cm and have short floral tubes which keep the flowers fairly tight to the stems. An unusual feature of Myrtillocactus is that the areoles may produce multiple flowers. The flowers are a greenish-white colour, waxy and somewhat translucent. These are followed by delicious edible fruit which resemble blue-berries. Myrtillocactus species are cold hardy to -4°C. They do well in raised garden beds, rockeries and large pots.

Myrtillocactus geometrizans commonly known as Blue Myrtle, Blueberry Cactus, Bilberry Cactus, Whortleberry Cactus or Blue Candle is a columnar cactus with ethnobotanical properties. It is native to Mexico and may reach 6 meters in the wild. This species is prized as an ornamental and a grafting stock for slower growing cacti such as Astrophytum, Ariocarpus and Lophophora. As the name indicates, Blue Myrtle has a bluish-green stem, and its spines are small like those of San Pedro cactus and like San Pedro and peyote it too contains mescaline. This makes it much easier to handle. This species is hardy to about -4°C. Elsewhere, it must be brought in for the winter. Blue myrtle bears several greenish-white flowers per areole. Following the flowers are delicious edible fruits that resemble blueberries.