Cleistocactus strausii
Silver Torch cactus can thrive in low-nitrogen soil without facing the consequences of low nitrogen. Too much water will make the plant weak and lead to root rot. 
Least Concern. This cactus is locally abundant in its native land and has few local threats to its survival.
This cactus can be propagated by cuttings or seed.
Generalist and specialist species
The distinction between generalists and specialists is not limited to animals. For example, some plants require a narrow range of temperatures, soil conditions and precipitation to survive while others can tolerate a broader range of conditions. A cactus could be considered a specialist species. It will die during winters at high latitudes or if it receives too much water.