Copiapoa or Pilocopiapoa is a genus of cacti from the Cactaceae family. These types of plants were named after the town of Copiapó in northern Chile, where they are native. There are about 26 species within this genus that come in distinctive shapes and sizes. Some varieties are small and multiply in clusters, while there are also species that are quite tall and have hundreds of stems covering a vast area. Normal conditions for these cacti are the extremely dry and hot climates present in the coastal deserts of South America.
Although species of Copiapoa exhibit a diverse set of physical characteristics, common features of such cacti include spherical or globose-cylindrical stems with distinct ribs and trumpet-shaped yellow flowers that sprout at the center of their clustered spines. Blossoms of these cacti are small to medium in size and approximately 1 to 2 inches (2.5 to 5 cm) in diameter. Most species also produce a white chalk-like coating that is excreted through the apex of the spines. This is a by-product of these cacti’s food synthesis and can be washed off by overhead watering.
Copiapoa cinerea is one of the most popularly collected species in this cacti group. A fully matured cinerea has thick jet black spines that cluster in groups of three or four and has the communal yellow flowers of the genus. Its body is smooth and globose in form, but can morph into a more cylindrical shape as it grows taller. Stems reach heights of 4 feet (1.2 m) with diameters of about 4 to 8 inches (10 to 20 cm). Ritter's tenebrosas, a variety of cinerea, has no spines in contrast, but the rest of the species’ physical attributes are still observed.
Another interesting species of Copiapoa is tenuissima. It is distinct among other cacti because it turns completely black when directly exposed to the sun. White fringed spines cover the cactus’ spherical body, which grows bright yellow flowers that bloom during spring and summer. Secretion of the white powdery substance provides a high color contrast of black and white, which is a trait that is exclusive to this cactus species.
Caring for these drought-tolerant Copiapoa plants requires minimal time and energy despite their slow growth. Potting them in wide-set containers is recommended for better root growth, as these cacti tend to spread across an area in clusters. Directly plotting them in rocky or sandy soil is also an alternative; however, exposure to frost can quickly kill these cacti.