The Cinerea Complex is hard to organize mainly because many of its members' population zones also overlap and hybridize in habitat. Some other members of this complex include Copiapoa cinerea v. albispina, C. cinerea subs. columna-alba, and C. melanohystrix.

Appearance:
The taxonomic representation of C. cinerea is physically characterized by possessing a crown of white wool, a ribbed stem, black spines, and a coat of protective farina over the stem. These characteristics were based solely upon the descriptions of the first ever collected plants which for the most part also had dark spines, though possesed one to three spines per areole. In habitat most cinerea have three to five spines per areole.

There are actually a few different spine colors that can also be displayed other than black; both white and tan, as well as brown have been observed in habitat. However, spines crack internally due to age and in habitat local algae will infiltrate these cracks and thus stain the spines a darker color. This is why the species was/is still characterized by the descriptor "black spines''. The same kinds of algae also stain the lower stems, where age and weathering has stripped the protective farina away. The result creates a stark contrast between white farina covered active growth and dark colored barked-up growth.

Cultivation:
Copiapoa cultivation is rather straightforward. Copiapoa like many other cacti are very rot prone, so a very porous and well draining soil is required. Copiapoa seem to do best with about 10%-20% of their potting mix being an organic compound like charcoal, coconut coir, or peat moss. The rest of the mix should be well draining mineral compounds such as pumice, decomposed granite, or scoria.

They enjoy full sun, although can be sensitive to harsher afternoon sun. They tend to do best in morning sun, with later afternoon shade.

In terms of hydration, they enjoy being watered every two to three weeks during their active growing season. This generally means we can stop watering when the temperature drops in fall and begin watering again when the temperature rises again in spring. They enjoy a thorough soak when watered during this time like all other cacti.

Copiapoa cinerea are considered to be very slow growing, although in my opinion they move at least a little faster than some other slow growing cacti such as ariocarpus. After a good soak you may notice that their ribs have swelled up somewhat and that they seem to gain at least some recognizable size over the course of a season.

Watch Out For:
Despite their hardiness in their natural environment, in cultivation Copiapoas are often prone to a few problems that most Chilean cacti are prone to. Although the Atacama Desert in Chile is one of the hottest in the world, cacti from here are notoriously prone to damage from overexposure and overheating. The reason for this is that although Cacti from the Atacama and Chile enjoy very arid seasons almost year round,  they also experience some unique weather conditions due to the coastal geography. In most areas a heavy coastal fog, called camanchaca, will roll through and drench everything. This fog pools around rocks, and even where the ground is less rocky is found to be hydrating the soil up to a few inches under the surface. This fog also acts to diffuse harsh sunlight as well. Coastal winds also cool the area. Perhaps it is due to these habitat conditions that Copiapoa actually grow more healthily in milder climates.

In greenhouse cultivation it is often found that copiapoas grown at temperatures in the high 50s Fahrenheit grow more optimally than those at higher temps, where some growers experience more sunburn and visible signs of dehydration. Ventilation or shade cloth up to 30% has been found to be most effective at mitigating heat or sun stress related problems. Chilean cacti are also somewhat vulnerable to cold and should be kept dry when temperatures drop to the low 40s Fahrenheit. Some growers will even fully withhold water if temperature is below 70, although outdoors in the Bay Area this will be challenging. I have had good success watering every three weeks when temperatures are in the mid to high 50s so far. A few cultivators will spray/mist their copiapoa and I have heard two reasons for this. One reason is to mist at a certain point of the day to mitigate the heat and recreate the effect of their natural habitat's coastal fogs. The other reason is for the intention of giving a very light hydration to just the top layer of soil.

One Last Thing:
The last bit I want to talk about is the moral obligation of having these cacti. The current conservation status of at least two-thirds of the genus Copiapoa needs to be reassessed. For instance C. cinerea has been classified both as vulnerable and as of least concern. The threats to these plants come from two causes. The first and longest standing threat is the environment. We can think of current Copiapoa populations as relics: the survivors of centuries and generations of diebacks due to the further and further desertification of the Atacama. Because of these environmental factors Copiapoa cinerea have not been able to germinate in habit successfully for many generations, potentially for centuries.

The other threat to these habitat populations is human intervention. Aside from development that has become all too familiar around the world, Copiapoa are also highly popular on the market. Many cacti currently for sale on some markets are not sustainably and responsibly collected specimens. The first Copiapoa cinerea specimens were also very irresponsibly poached over years and taken out of Chile to their collectors' respective home countries. Many of these plants were already centuries old individuals before being pulled and then forced to survive in captivity for another forty or more years. Even today, people still irresponsibly poach these plants from habitat despite the fact that there already exist generations of plants cultivated from the early specimens. We want to try and educate people on this part of the trade and steer them towards specimens that have been cultivated from seed. This way even if we can't return the plants that have been taken, we can educate the market and hopefully mitigate future poaching.