Myrtillocactus is a genus of cacti that contains four different species. Native to parts of Mexico and Guatemala, they are grown as landscaping plants and houseplants in many places. Each of the species produces fruit that is similar to a bilberry or whortleberry, so the scientific name, Myrtillocactus, is related to the scientific name of the bilberry plant, Vaccinium myrtillus.
All species of myrtillocactus produce flowers that range in color from green to white, and can measure from less than 1 inch (2.54 cm) to more than 2 inches (5.08 cm) long, depending on the species. These blooms typically give way to fruits that are red to dark purple in color and resemble bilberries or blueberries. While some are more widely consumed than others, all species of these plants produce edible fruits.
Myrtillocacti are tall and tree-like, consisting of a central trunk with many branches. The trunk and branches have up to eight distinct ribs. Their full height can range from 4 feet (1.21 m) to 16 feet (4.87 m), depending on the species.
Of the four species of myrtillocacti, M. geometrizans is most commonly grown as a potted or landscape plant. Also called Blue Candle or whortleberry cactus, the fruit of this cultivar is the most widely eaten by people. This species should only be grown outdoors in more temperate climates, as it can sustain frost damage at 25°F (3.88°C). It can also be grown indoors as a potted plant, however, a potted Blue Candle will seldom grow large enough to flower and produce fruit.
M. schenkii is the tallest species of myrtillocacti, sometimes reaching up to 16 feet (4.87 m). Its common name is garambullo. Myrtillocactus fruits are often sold in Mexican markets under the name garambullo as well.
The M. eichlamii species is the only myrtillocactus that is native to Guatemala. These cactii produce the largest flowers in the genus, with white flowers that may be over two inches in diameter. M. eichlamii are the least commonly known myrtillocacti, and are somewhat rare even in their native habitat.
Candelabra cactus is the common name of M. cochal. This is the most shrub-like of the genus, and usually has a short trunk with many branches. The candelabra variety can grow up to 10 ft (about 3 m) tall.
All species of myrtillocactus are native to temperate desert regions, so they grow best outdoors in similar regions. Cuttings of the cacti will only take root in hot weather. If they are grown in regions with frequent winter freezes, they should be potted and kept inside during the winter months.
